For Peer Review Only Journal: BMJ Open

BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

Radiation-related Anxiety among Public Health Nurses in the Fukushima Prefecture after the Accident at the Fukushima Daiichi Nuclear Power Station

For peer review only Journal: BMJ Open

Manuscript ID bmjopen-2016-013564

Article Type: Research

Date Submitted by the Author: 21-Jul-2016

Complete List of Authors: Yoshida, Koji; Nagasaki University Graduate School of Biomedical Sciences, Health Sciences; Fukushima Medical University, Education Center for Disaster Medicine Orita, Makiko; Atomic Bomb Disease Institute, Nagasaki University, , Global Health, Medicine and Welfare Goto, Aya; Fukushima Medical University, Integrated Science and Humanities Kumagai, Atsushi; Fukushima Medical University, Education Center for Disaster Medicine Yasui, Kiyotaka; Fukushima Medical University, Education Center for Disaster Medicine Ohtsuru, Akira; Fukushima Medical University, Radiation Health Management Hayashida, Naomi ; Atomic Bomb Disease Institute, Nagasaki University, http://bmjopen.bmj.com/ Promotion of Collaborative Research on Radiation and Environment Health Effects Kudo, Takashi; Atomic Bomb Disease Institute, Nagasaki University, Radioisotope Medicine Yamashita, Shunichi ; Atomic Bomb Disease Institute, Nagasaki University, Radiation Medical Sciences Takamura, Noboru; Atomic Bomb Disease Institute, Nagasaki University, ; on September 24, 2021 by guest. Protected copyright. Primary Subject Nursing Heading:

Secondary Subject Heading: Public health

public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power Keywords: Station, Sense of Coherence-13

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1 2 3 4 5 6 1 Radiation-related Anxiety among Public Health Nurses in the Fukushima 7 8 2 Prefecture after the Accident at the Fukushima Daiichi Nuclear Power Station 9 10 11 3 12 13 4 Koji Yoshida1,2*, Makiko Orita3, Aya Goto4, Atsushi Kumagai2, Kiyotaka Yasui2, Akira 14 15 5 For peer6 review7 only8 3 16 5 Ohtsuru , Naomi Hayashida , Takashi Kudo , Shunichi Yamashita , Noboru Takamura 17 18 6 19 20 21 7 1 Department of Health Sciences, Nagasaki University Graduate School of Biomedical 22 23 8 Sciences, Nagasaki, Japan 24 25 9 26 2 Education Center for Disaster Medicine, Fukushima Medical University, Fukushima, 27 28 10 Japan 29 30 11 3 Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, 31 32 33 12 Nagasaki University, Nagasaki, Japan 34 http://bmjopen.bmj.com/ 35 13 4 Center for Integrated Science and Humanities, Fukushima Medical University, 36 37 38 14 Fukushima, Japan 39 40 15 5 Department of Radiation Health Management, Fukushima Medical University School 41

42 on September 24, 2021 by guest. Protected copyright. 43 16 of Medicine, Fukushima, Japan 44 45 17 6 Division of Promotion of Collaborative Research on Radiation and Environment 46 47 48 18 Health Effects, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 49 50 19 7 Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki 51 52 53 20 University, Nagasaki, Japan 54 55 21 8 Department of, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 56 57 58 59 1 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 2 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 22 7 8 23 *Corresponding author 9 10 11 24 Koji Yoshida, R.N, Ph.D. 12 13 25 Department of Health Sciences, Nagasaki University Graduate School of Biomedical 14 15 For peer review only 16 26 Sciences, Nagasaki, Japan 17 18 27 171 Sakamoto, Nagasaki 8508520, Japan 19 20 21 28 Email: koujiy@nagasakiu.ac.jp (KY) 22 23 29 TEL: +81958197195 24 25 30 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 2 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 3 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 31 Abstract 7 8 32 Objective: In Japan, public health nurses (PHNs) play important roles in managing the 9 10 11 33 health of local residents, especially after a disaster. In this study, we assessed radiation 12 13 34 anxiety and the stress processing capacity of PHNs in the Fukushima Prefecture in 14 15 For peer review only 16 35 Japan, after the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS). 17 18 36 Methods: We conducted a questionnaire survey among the PHNs (n=430) in July of 19 20 21 37 2015 via mail by post. The questions included demographic factors (sex, age, and 22 23 38 employment position), knowledge about radiation, degree of anxiety about radiation at 24 25 39 26 the time of the FDNPS accident (and at present), when answering the questions about 27 28 40 radiation, and the Sense of Coherence13 (SOC13). We classified the low and high 29 30 41 levels of anxiety when answering questions about radiation, and compared the 31 32 33 42 anxietynegative () group with the anxietypositive (+) group. 34 http://bmjopen.bmj.com/ 35 43 Results: Of the PHNs, 269 (62.6%) were classified in the anxiety () group and 161 36 37 38 44 (37.4%) were in the anxiety (+) group. When the multivariate logistic regression 39 40 45 analysis was conducted, the PHNs at the time of the accident (OR: 2.37, p=0.007), 41

42 on September 24, 2021 by guest. Protected copyright. 43 46 current general anxieties about radiation (OR: 3.56, p<0.001), current possession of 44 45 47 materials to obtain knowledge about radiation (OR: 2.11, p=0.006), and knowledge of 46 47 48 48 the childhood thyroid cancer increase after the Chernobyl accident (OR: 1.69, p=0.035) 49 50 49 were significantly associated with anxiety after the FDNPS accident. The mean SOC13 51 52 53 50 was 43.0±7.7, with no significant difference between anxiety () group and anxiety (+) 54 55 51 group (p=0.47). 56 57 58 59 3 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 4 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 52 Conclusions: Our study suggested that anxiety about radiation was associated with 7 8 53 materials and knowledge about radiation in the PHNs of Fukushima Prefecture four 9 10 11 54 years after the FDNPS accident. It is important for PHNs to obtain knowledge and 12 13 55 teaching materials about radiation, and radiation education programs for PHNs must be 14 15 For peer review only 16 56 established in areas that have nuclear power stations and other nuclear facilities. 17 18 57 19 20 21 58 Keywords: public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power 22 23 59 Station, Sense of Coherence13 24 25 60 26 27 28 61 Strengths and limitations of this study 29 30 62 ・We could assess radiation anxiety and the stress processing capacity of PHNs in the 31 32 33 63 Fukushima Prefecture in Japan, after the accident at the FDNPS. 34 http://bmjopen.bmj.com/ 35 64 ・We believe that this study regarding the PHNs’ situation in the Fukushima Prefecture 36 37 38 65 four years after the FDNPS disaster will be very important in the provision of future 39 40 66 support. 41

42 on September 24, 2021 by guest. Protected copyright. 43 67 ・We could not obtain sufficient information on the anxietyrelated factors, such as 44 45 68 detailed consultation contents and other information. 46 47 48 69 49 50 70 51 52 53 54 55 56 57 58 59 4 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 5 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 71 Introduction 7 8 72 On March 11, 2011, the Great East Japan Earthquake struck the east coast of 9 10 11 73 Japan. This large earthquake and tsunami caused immense damage, including that to the 12 13 74 Fukushima Daiichi Nuclear Power Station (FDNPS) [14]. After the accident at the 14 15 For peer review only 16 75 FDNPS, the Fukushima prefectural government immediately issued instructions for the 17 18 76 evacuation of those areas within a 20 km radius of the FDNPS, and they also instructed 19 20 21 77 sheltering in the areas between 20 km and 30 km from the FDNPS. Beyond the 30 km 22 23 78 radius, additional areas were designated “deliberate evacuation areas” if there was 24 25 79 26 concern that the cumulative doses of radiation might reach 20 mSv per year in those 27 28 80 areas [2]. Despite the low estimated and measured external and internal exposure doses 29 30 81 just after the accident, many residents of the Fukushima Prefecture evacuated inside or 31 32 33 82 outside the prefecture [58]. 34 http://bmjopen.bmj.com/ 35 83 In the report by the World Health Organization (WHO) on the health impacts 20 36 37 38 84 years after the Chernobyl accident, mental health was described as the most serious 39 40 85 public health problem resulting from that nuclear accident [911]. Based on the lessons 41

42 on September 24, 2021 by guest. Protected copyright. 43 86 learned from the Chernobyl accident, the Fukushima Health Management Survey 44 45 87 (FHMS) was initiated to assess the health impacts, including mental health, of the 46 47 48 88 residents by the Fukushima prefectural government and the Fukushima Medical 49 50 89 University [12, 13]. According to the results of this survey, the residents of the 51 52 53 90 Fukushima Prefecture were exposed to a higher risk of not only physical problems, such 54 55 91 as diabetes and obesity, but also mental problems (including the risk perception of the 56 57 58 59 5 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 6 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 92 health effects of radiation) [14, 15]. 7 8 93 In Japan, public health nurses (PHNs) play important roles in managing the health 9 10 11 94 of local residents, especially after this disaster. While they were themselves victims of 12 13 95 the radiation disaster, they had to respond to the residents’ anxieties about radiation 14 15 For peer review only 16 96 exposure, despite their lack of professional knowledge on this topic. 17 18 97 In this study, we conducted a survey to clarify the radiation anxiety and stress 19 20 21 98 processing capacity of the PHNs in the Fukushima Prefecture, after the nuclear accident 22 23 99 at the FDNPS. 24 25 26 100 27 28 101 Materials and Methods 29 30 102 Study population and data collection 31 32 33 103 We conducted a questionnaire survey among the PHNs in the Fukushima 34 http://bmjopen.bmj.com/ 35 104 Prefecture located in Northeastern Japan, which was severely affected by the earthquake, 36 37 38 105 tsunami, and FDNPS accident following the Great East Japan Earthquake in 2011. The 39 40 106 survey was conducted in July of 2015 via mail by post, and contained questions about 41

42 on September 24, 2021 by guest. Protected copyright. 43 107 the demographic factors (sex, age, activity area, and employment position) and 44 45 108 knowledge of the PHNs about radiation before and after the accident at the FDNPS, as 46 47 48 109 well as their degree of anxiety about radiation at the time of the FDNPS accident (and at 49 50 110 present), and their mental health status. The degree of anxiety was rated on a 10point 51 52 53 111 Likert scale ranging from no anxiety to having a lot of anxiety; we defined 15 as 54 55 112 “anxiety ()” and 610 as “anxiety (+).” 56 57 58 59 6 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 7 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 113 To measure the PHNs’ stress management capability, we used the Japanese 7 8 114 version of the Sense of Coherence13 (SOC13). The SOC13 consists of three 9 10 11 115 dimensions (comprehensibility, manageability, and meaningfulness) that are equally 12 13 116 weighted to create an overall (total) score. The score ranges from 791, with a higher 14 15 For peer review only 16 117 score representing a stronger sense of coherence [16]. 17 18 118 19 20 21 119 Statistical analysis 22 23 120 We classified the low and high levels of anxiety when answering the questions 24 25 121 26 about radiation, and compared the anxiety () group and anxiety (+) group by using the 27 28 122 chisquare test and ttest as univariate analyses. A multiple logistic regression analysis 29 30 123 was then used to calculate the odds ratio (OR), and its 95% confidence interval (95% 31 32 33 124 CI) was used to identify the factors independently associated with the anxiety level. A 34 http://bmjopen.bmj.com/ 35 125 pvalue of less than 0.05 was considered to be significant, and the statistical analysis 36 37 38 126 was performed using SPSS Statistics 22.0 (IBM Japan, Tokyo, Japan). 39 40 127 41

42 on September 24, 2021 by guest. Protected copyright. 43 128 Ethics statement 44 45 129 This study was approved by the ethics committee of the Fukushima Medical 46 47 48 130 University (No. 2251), and conducted in accordance with the guidelines specified in the 49 50 131 Declaration of Helsinki. 51 52 53 132 54 55 56 57 58 59 7 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 8 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 133 Results 7 8 134 A total of 458 PHNs responded to the survey, and 430 of those PHNs (93.9%) 9 10 11 135 completed all of the questions. The number of women was 416 (96.7%), and 153 12 13 136 (35.6%) were 50 years old or older. The number of PHNs with less than 10 years of 14 15 For peer review only 16 137 working experience was 124 (22.8%), and 306 (71.2%) had ten years or more. There 17 18 138 were 119 participants (27.7%) with managerial positions. At the time of the accident, 19 20 21 139 330 (76.8%) worked as PHNs and 62 (14.4%) were still in training. The number of 22 23 140 those in Hamadori, which became the evacuation area of the FDNPS accident, was 83 24 25 141 26 (19.3%) (Table 1). 27 28 142 29 30 143 Table 1. Basic characteristics of the study participants. 31 32 33 Variable Number (%) 34 http://bmjopen.bmj.com/ 35 Gender Women 416(96.7) 36 Men 14(3.3) 37 38 Age 2029 years old 92(21.4) 39 3039 years old 72(16.7) 40 4049 years old 113(26.3) 41 ≥50 years old 153(35.6) 42 on September 24, 2021 by guest. Protected copyright. 43 Tenure as a public health nurse <10 years 124(28.8) 44 ≥10 years 306(71.2) 45 Nursing experience in a hospital Yes 149(34.7) 46 No 281(65.3) 47 Activity area Hamadori 83(19.3) 48 49 Other area (Nakadori, Aizu et al.) 347(80.7) 50 Position in the workplace Manager (director, chief) 119(27.7) 51 Staff 311(72.3) 52 Occupation at the time of the Public health nurse 330(76.8) 53 54 accident Other occupations (mostly nurses) 38(8.8) 55 Students 62(14.4) 56 57 144 58 59 8 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 9 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 145 Of the PHNs, 269 were classified in the anxiety () group and 161 were in the 7 8 146 anxiety (+) group (Table 2). A significantly higher ratio of PHNs younger than 40 years 9 10 11 147 old was observed in the anxiety (+) group (p<0.001, Table 2). Likewise, higher ratios of 12 13 148 PHNs with less than 10 years of working experience, staff positions, and nursing 14 15 For peer review only 16 149 licenses were observed in the anxiety (+) group (p<0.001, respectively, Table 2). On the 17 18 150 other hand, no significant differences were observed between the two groups in the 19 20 21 151 activity area, education curriculum, and seminars before or after the accident (p=0.62, 22 23 152 p=0.16, p=0.60, and p=0.13, respectively, Table 2). In addition, there was no significant 24 25 153 26 difference in the mean points in the SOC13 observed between the two groups (p=0.47, 27 28 154 Table 2). 29 30 155 31 32 33 156 Table 2. Participant’s demographic factors, educational history, and mental health 34 http://bmjopen.bmj.com/ 35 157 via anxiety with regard to questions about radiation after the FNPS accident. 36 37 38 Anxiety () Anxiety (+) 39 Variable Unit pvalues 40 (n=269) (%) (n=161) (%) 41

42 Gender Women/ 262(97.4)/ 154(95.7)/ on September 24, 2021 by guest. Protected copyright. 0.32 43 Men 7(2.6) 7(4.3) 44 Age <40 years old/ 77(28.6)/ 87(54.0)/ 45 <0.001 46 ≥40 years old 192(71.4) 74(46.0) 47 Working experience as a public <10 years/ 53(19.7)/ 71(44.1)/ <0.001 48 health nurse ≥10 years 216(80.3) 90(55.9) 49 Activity area Hamadori/ 54(20.1)/ 29(18.0)/ 50 0.62 51 Other area 215(79.9) 132(72.0) 52 Position in the workplace Manager/ 88(32.7)/ 31(19.3)/ 0.003 53 Staff 181(67.3) 130(80.7) 54 Occupation at the time of the PHNs/ 55 230(85.5)/ 100(62.1)/ accident Others (nurses, <0.001 56 39(14.5) 61(37.9) 57 students) 58 59 9 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 10 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 Did you have children ≤15 6 years old at the time of the Yes 110(40.9) 59(36.6) 0.42 7 8 accident? 9 Education history in Yes 114(42.4) 80(49.7) 0.16 10 curriculum 11 Education history in seminar 12 Yes 25(9.3) 12(7.5) 0.60 13 before the accident 14 Education history in seminar Yes 247(91.8) 140(87.0) 0.13 15 after the accidentFor peer review only 16 Frequency of participation in Once/ 47(19.0)/ 42(29.6)/ 17 0.02 18 seminars Plural 200(81.0) 98(70.4) 19 SOC13 total points Mean 44.0 41.4 0.47 20 21 158 22 23 159 In the anxiety (+) group, the ratio of those having current anxiety about radiation 24 25 26 160 was significantly higher than that in the anxiety () group (p<0.001, Table 3). On the 27 28 161 other hand, in the anxiety () group, the ratios with difficulty answering the questions 29 30 162 about radiation, currently having the materials to obtain knowledge about radiation, and 31 32 33 163 having knowledge about childhood thyroid cancer increases after the Chernobyl 34 http://bmjopen.bmj.com/ 35 164 accident were significantly higher than in the anxiety (+) group (p<0.05, p<0.01, and 36 37 38 165 p<0.05, respectively, Table 3). However, there were no significant changes between the 39 40 166 two groups in the anxiety about radiation at the time of the accident and the recognition 41

42 on September 24, 2021 by guest. Protected copyright. 43 167 of health effects (such as late effects and genetic effects) due to radiation exposure 44 45 168 (p=0.68, p=0.79, and p=0.20, respectively, Table 3). 46 47 48 169 49 50 170 Table 3. Participants’ anxiety, recognition, and knowledge about radiation via 51 52 53 171 anxiety with regard to answering the questions about radiation after the FDNPS 54 55 172 accident. 56 57 58 59 10 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 11 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 Anxiety () Anxiety (+) 7 Question Unit pvalues 8 (n=269) (%) (n=161) (%) 9 10 Degree of anxiety about radiation at anxiety ()/ 99(36.8)/ 56(34.8)/ 11 0.68 the time of the FDNPS accident anxiety (+) 170(63.2) 105(65.2) 12 Degree of anxiety about radiation anxiety ()/ 251(93.3)/ 130(80.7)/ 13 <0.001 14 currently anxiety (+) 18(6.7) 31(19.3) 15 Do you thinkFor that delayed peer effects such review only 16 as malignancies occur due to radiation 17 Yes 37(13.8) 33(20.5) 0.79 18 exposure following the Fukushima 19 accident? 20 Do you think that genetic effects in 21 offspring occur due to radiation 22 Yes 33(12.3) 27(16.8) 0.20 23 exposure following the Fukushima 24 accident? 25 Did you have a difficult time 26 answering the questions about Yes 216(80.3) 115(71.4) 0.04 27 radiation? 28 29 Did you have the materials to obtain 30 knowledge about radiation at the time Yes 87(32.3) 40(24.8) 0.10 31 of the accident? 32 Do you currently have the materials to 33 Yes 233(86.6) 118(73.3) 0.01 34 obtain knowledge about radiation? http://bmjopen.bmj.com/ Did you know about the three 35 Yes 64(23.8) 42(26.1) 0.64 36 principles of radiation protection? 37 Did you know about the annual dose 38 Yes 20(12.4) 11(6.8) 0.99 39 limit for the general public? Did you know about the halflife of 40 Yes 129(48.0) 77(47.8) 0.99 41 radioactive substances? 42 Did you know about childhood on September 24, 2021 by guest. Protected copyright. 43 thyroid cancer increases after the Yes 213(79.2) 109(67.7) 0.01 44 45 Chernobyl accident? 46 47 173 48 49 174 When the logistic regression analysis was conducted, following the adjustment 50 51 175 for confounding factors, being a PHN at the time of the accident (OR: 2.37, p<0.01), 52 53 54 176 current general anxieties about radiation (OR: 3.56, p<0.001), currently having the 55 56 177 materials to obtain knowledge about radiation (OR: 2.11, p<0.01), and having 57 58 59 11 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 12 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 178 knowledge about childhood thyroid cancer increases after the Chernobyl accident (OR: 7 8 179 1.69, p=0.04) were all significantly associated with anxiety after the FDNPS accident 9 10 11 180 (Table 4). 12 13 181 14 15 For peer review only 16 182 Table 4. Odds ratios and 95% confidence intervals of the study variables for 17 18 183 anxiety (+) when answering questions about radiation, as assessed by the logistic 19 20 21 184 regression analysis. 22 95% confidence 23 Variable Unit Odds ratio pvalue 24 interval 25 Age ≥40 years old 0.64 0.361.15 0.13 26 Manager in the No 1.14 0.652.00 0.66 27 workplace 28 Public health nurse at 29 No 2.37 1.274.42 <0.01 30 the time of the accident 31 Current degree of anxiety (+) 3.56 1.826.96 <0.001 32 anxiety about radiation 33 34 Difficulty answering http://bmjopen.bmj.com/ 35 radiation questions in No 1.27 0.762.12 0.37 36 the past 37 Currently have 38 materials to obtain 39 No 2.11 1.2483.60 <0.01 40 knowledge about 41 radiation 42 Knowledge about on September 24, 2021 by guest. Protected copyright. 43 childhood thyroid 44 No 1.69 1.042.75 0.04 45 cancer increase after the 46 Chernobyl accident 47 185 48 49 50 51 52 53 54 55 56 57 58 59 12 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 13 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 186 Discussion 6 7 187 This study was conducted four years after the FDNPS disaster to provide 8 9 10 188 educational support for PHNs who receive many consultations from residents. In 11 12 189 univariate analysis, younger and inexperienced PHNs had higher anxiety with regard to 13 14 190 communicating with residents about radiation. When adjusting for other variables, those 15 For peer review only 16 17 191 PHNs who were students at the time of the accident had higher anxiety when 18 19 192 communicating with residents about radiation. Our results suggested that experience as 20 21 22 193 a professional during the FDNPS accident is important. Although many of the PHNs 23 24 194 had knowledge about the Chernobyl accident, they could not properly communicate the 25 26 27 195 health effects of radiation with the residents, which caused anxiety in the residents after 28 29 196 the accident at the FDNPS. In addition, our results showed that having the materials to 30 31 32 197 obtain knowledge about radiation was independently associated with anxiety about the 33 34 198 FDNPS accident. http://bmjopen.bmj.com/ 35 36 37 199 These results suggest that continuous effort is necessary to provided education 38 39 200 and materials among the PHNs in the Fukushima Prefecture for them to gain knowledge 40 41 201 about radiation, including the health effects caused by radiation exposure [17]. Some 42 on September 24, 2021 by guest. Protected copyright. 43 44 202 education initiatives have been undertaken in the prefecture after the nuclear accident, 45 46 203 which includes Fukushima Medical University’s disaster education for undergraduates 47 48 49 204 and health literacy training for public health nurses for field practitioners [18, 19]. 50 51 205 Appropriate and sustainable allocation of financial and human resources is needed to 52 53 54 206 continue and expand such activities. 55 56 207 The SOC13 was employed to estimate the stress management capability of the 57 58 59 13 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 14 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 208 PHNs in this study. There was no significant difference in the mean points in the 7 8 209 SOC13 observed between the anxiety () group and anxiety (+) group. This result, as 9 10 11 210 well as other study, may suggest that factor of lifestyle related [20]. On the other hand, 12 13 211 Eriksson et al. showed that individuals with high scores in the SOC13 are better able to 14 15 For peer review only 16 212 cope with chronic stress than those with low scores [21]. In other studies, the average 17 18 213 points of the nursing students at two Japanese universities were 50.2±7.7 and 53.8±10.7, 19 20 21 214 respectively [22, 23], and the average score of elderly individuals in the Nagasaki 22 23 215 Prefecture in Japan was 45.0 [24]. In this study, the average score (43.0±7.7) was lower 24 25 216 26 than those in other studies, and it was substantially lower when compared to those of 27 28 217 nursing students. Accordingly, there is a need for planning of stress management 29 30 218 capacity improvement for the PHNs in Fukushima Prefecture with low SOC score. 31 32 33 219 The correspondence of the disaster affected the stress management capability, and 34 http://bmjopen.bmj.com/ 35 220 might cause a worsening of chronic stress. According to the FHMS, which includes 36 37 38 221 monitoring the mental health and daily lives of Fukushima residents and providing 39 40 222 proper care for them, the mental health status of the residents in the Fukushima 41

42 on September 24, 2021 by guest. Protected copyright. 43 223 Prefecture was very poor [13]. Thus, the mental health of the residents was greatly 44 45 224 affected by the disaster, and a similar impact could be expected from the PHNs who 46 47 48 225 work in the Fukushima Prefecture. Therefore, mental support is important for the PHNs, 49 50 226 as well as for the residents of the Fukushima Prefecture. 51 52 53 227 The present study has several limitations. For example, we could not obtain 54 55 228 sufficient information on the anxietyrelated factors, such as detailed consultation 56 57 58 59 14 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 15 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 229 contents and other information. However, we believe that this study regarding the PHNs’ 7 8 230 situation in the Fukushima Prefecture four years after the FDNPS disaster will be very 9 10 11 231 important in the provision of future support. 12 13 232 In conclusion, we conducted a survey of the radiation anxiety and stress 14 15 For peer review only 16 233 processing capacity of PHNs in the Fukushima Prefecture four years after the nuclear 17 18 234 accident at the FDNPS, and determined that it is important for PHNs to obtain 19 20 21 235 knowledge and teaching materials about radiation. In addition to Fukushima, radiation 22 23 236 education programs for PHNs must be established in areas that have nuclear power 24 25 237 26 stations and other nuclear facilities. 27 28 238 29 30 239 Footnotes 31 32 33 240 Contributorship statement 34 http://bmjopen.bmj.com/ 35 241 ・Koji Yoshida conceived and designed the experiments, analyzed the data, wrote the 36 37 38 242 paper, prepared Tables. 39 40 243 ・Makiko Orita, Akira Ohtsuru, Aya Goto, Atsushi Kumagai and Kiyotaka Yasui 41

42 on September 24, 2021 by guest. Protected copyright. 43 244 contributed materials, reviewed drafts of the paper. 44 45 245 ・Naomi Hayashida, Takashi Kudo, and Shunichi Yamashita designed the experiments, 46 47 48 246 reviewed drafts of the paper. 49 50 247 • Noboru Takamura conceived and designed the experiments, wrote the paper, 51 52 53 248 reviewed drafts of the paper. 54 55 249 56 57 58 59 15 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 16 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 250 Competing interests 7 8 251 There are no competing interests 9 10 11 252 12 13 253 Funding 14 15 For peer review only 16 254 This study was partly supported by Japan Society for Promotion of Science. 17 18 255 19 20 21 256 Data sharing statement 22 23 257 No additional data are available. 24 25 258 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 16 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 17 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 259 6 260 7 References 8 261 1. United Nations Scientific Committee on the Effects of Atomic Radiation. 9 10 11 262 UNSCEAR 2013 Report Volume I Report to the general assembly scientific 12 13 263 annex A: Levels and effects of radiation exposure due to the nuclear accident 14 15 For peer review only 16 264 after the 2011 Great eastJapan earthquake and tsunami. Available: 17 18 265 http://www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf 19 20 21 266 (accessed 16 July 2016). 22 23 267 2. International Atomic Energy Agency. The Fukushima Daiichi accident Technical 24 25 268 26 Volume 4. Radiological Consequences. Vienna: International Atomic Energy 27 28 269 Agency (IAEA). 2015: 1250. 29 30 270 3. Nuclear Emergency Response Headquarters of Japanese Government. Report of 31 32 33 271 Japanese government to the IAEA ministerial conference on nuclear safety. The 34 http://bmjopen.bmj.com/ 35 272 Accident at TEPCO’s Fukushima nuclear power stations. Available: 36 37 38 273 http://japan.kantei.go.jp/kan/topics/201106/iaea_houkokusho_e.html (accessed 39 40 274 16 July 2016). 41

42 on September 24, 2021 by guest. Protected copyright. 43 275 4. Nuclear Emergency Response Headquarters of Japanese Government. Additional 44 45 276 report of the Japanese government to the IAEA—The Accident at TEPCO’s 46 47 48 277 Fukushima nuclear power stations (Second Report). Available: 49 50 278 https://www.iaea.org/newscenter/focus/fukushima/additionaljapanreport 51 52 53 279 (accessed 16 July 2016). 54 55 280 5. Nagataki S, Takamura N, Kamiya K, et al. Measurements of individual radiation 56 57 58 59 17 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 18 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 281 doses in residents living around the Fukushima Nuclear Power Plant. Rad Res. 7 8 282 2013;180: 439447. doi: 10.1667/RR13351.1 9 10 11 283 6. Nagataki S, Takamura N. A review of the Fukushima nuclear reactor accident: 12 13 284 radiation effects on the thyroid and strategies for prevention. Curr Opin 14 15 For peer review only 16 285 Endocrinol Diabetes Obes. 2014;21: 384393. doi: 17 18 286 10.1097/MED.0000000000000098 19 20 21 287 7. Ishikawa T, Yasumura S, Ozasa K, et al. The Fukushima Health Management 22 23 288 Survey: estimation of external doses to residents in Fukushima Prefecture. Sci 24 25 289 26 Rep. 2015;5: 12712. 111. doi: 10.1038/srep12712 27 28 290 8. Yoshida K, Hashiguchi K, Taira Y, et al. Importance of personal dose equivalent 29 30 291 evaluation in Fukushima in overcoming social panic. Radiat Prot Dosimetry. 31 32 33 292 2012;151(1): 1446. doi: 10.1093/rpd/ncr466 34 http://bmjopen.bmj.com/ 35 293 9. WHO (World Health Organization) 2005a. Health Effects of the Chernobyl 36 37 38 294 Accident and Special Health Care Programmes. Available: 39 40 295 http://www.who.int/ionizing_radiation/a_e/chernobyl/EGH%20Master%20file 41

42 on September 24, 2021 by guest. Protected copyright. 43 296 %202005.08.24.pdf. (accessed 16 July 2016). 44 45 297 10. WHO (World Health Organization) 2005b. Chernobyl: The true scale of the 46 47 48 298 accident; 20 Years Later a UN Report Provides Definitive Answers and Ways to 49 50 299 Repair Lives. Available: 51 52 53 300 http://www.who.int/mediacentre/news/releases/2005/pr38/en/ (accessed 16 July 54 55 301 2016). 56 57 58 59 18 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 19 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 302 11. WHO (World Health Organization). Health effects of the Chernobyl Accident 7 8 303 and Special Health Care Programmes. Geneva:WHO 2006. Available: 9 10 11 304 http://www.who.int/ionizing_radiation/chernobyl/who_chernobyl_report_2006.p 12 13 305 df#search=%2715.+WHO+%28World+Health+Organization%29.+Health+effect 14 15 For peer review only 16 306 s+of+the+Chernobyl+Accident+and+Special+Health+Car%27.pdf. (accessed 16 17 18 307 July 2016). 19 20 21 308 12. Yasumura S, Hosoya M, Yamashita S, et al. Study Protocol for the Fukushima 22 23 309 Health Management Survey. J Epidemiol. 2012;22: 375383. PMID: 22955043 24 25 310 26 13. Yabe H, Suzuki Y, Mashiko H, et al. Psychological distress after the Great East 27 28 311 Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident: results 29 30 312 of a mental health and lifestyle survey through the Fukushima Health 31 32 33 313 Management Survey in FY2011 and FY2012. Fukushima J Med Sci. 2014;60(1): 34 http://bmjopen.bmj.com/ 35 314 5767. PMID: 25030715 36 37 38 315 14. Ohira T, Hosoya M, Yasumura S, et al. Effect of Evacuation on Body Weight 39 40 316 After the Great East Japan Earthquake. Am J Prev Med. 2016;50(5): 55360. doi: 41

42 on September 24, 2021 by guest. Protected copyright. 43 317 10.1016/j.amepre.2015.10.008 44 45 318 15. Satoh H, Ohira T, Hosoya M, et al. Evacuation after the Fukushima Daiichi 46 47 48 319 Nuclear Power Plant Accident Is a Cause of Diabetes: Results from the 49 50 320 Fukushima Health Management Survey. J Diabetes Res. 2015: 627390. doi: 51 52 53 321 10.1155/2015/627390 54 55 322 16. Antonovsky A. The structure and properties of the sense of coherence scale. Soc 56 57 58 59 19 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 20 of 21 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 323 Sci Med. 1993;36(6): 72533. PMID: 8480217 7 8 324 17. Konishi E, Nagai T, Kobayashi M, et al. PostFukushima radiation education for 9 10 11 325 public health nursing students: a case study. Int Nurs Rev. 2016;63(2): 2929. 12 13 326 doi: 10.1111/inr.12244 14 15 For peer review only 16 327 18. Ohtsuru A, Tanigawa K, Kumagai A, et al. Nuclear disasters and health: lessons 17 18 328 learned, challenges, and proposals. Lancet. 2015;386(9992): 489497. doi: 19 20 21 329 http://dx.doi.org/10.1016/S01406736(15)609941 22 23 330 19. Goto A, Lai AY, Rudd RE. Health literacy training for public health nurses in 24 25 331 26 Fukushima: A multisite program evaluation. Japan Med Assoc J. 2015;58(3): 27 28 332 6977. PMID: 26870621 29 30 333 20. Wainwright NW, Surtees PG, Welch AA, et al. Healthy lifestyle choices: could 31 32 33 334 sense of coherence aid health promotion? J Epidemiol Community Health. 34 http://bmjopen.bmj.com/ 35 335 2007;61(10): 8716. doi: 10.1136/jech.2006.056275 36 37 38 336 21. Eriksson M, Lindström B. Antonovsky's sense of coherence scale and the 39 40 337 relation with health: a systematic review. J Epidemiol Community Health. 41

42 on September 24, 2021 by guest. Protected copyright. 43 338 2006;60(5): 37681. doi: 10.1136/jech.2005.041616 44 45 339 22. Ohki T, Ihara M. A nursing student demonstration in the adult nursing practice 46 47 48 340 and Sense of chherence (SOC). The Showa University journal of nursing and 49 50 341 rehabilitation sciences. 2013;11: 4348. (in Japanese) 51 52 53 342 23. Egami C. Relationship between sense of coherence and mental health at nursing 54 55 343 student. The Japan Society of Health Sciences of Mind and Body. 2008;4(2), 56 57 58 59 20 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 21 of 21 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 344 111116. (in Japanese) 7 8 345 24. Teraoka S, Hayashida N, Shinkawa T, et al. Good stress management capability 9 10 11 346 is associated with lower body mass index and restful sleep in the elderly. Tohoku 12 13 347 J Exp Med. 2013;229(1): 510. PMID: 23196278 14 15 For peer review only 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 21 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

Radiation-related Anxiety among Public Health Nurses in the Fukushima Prefecture after the Accident at the Fukushima Daiichi Nuclear Power Station

For peer review only Journal: BMJ Open

Manuscript ID bmjopen-2016-013564.R1

Article Type: Research

Date Submitted by the Author: 03-Sep-2016

Secondary Subject Heading: Public health

public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power Keywords: Station, Sense of Coherence-13

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42 on September 24, 2021 by guest. Protected copyright. 43 16 of Medicine, Fukushima, Japan 44 45 17 6 Division of Promotion of Collaborative Research on Radiation and Environment 46 47 48 18 Health Effects, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 49 50 19 7 Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki 51 52 53 20 University, Nagasaki, Japan 54 55 21 8 Department of, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 56 57 58 59 1 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 2 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 2 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 3 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 31 Abstract 7 8 32 Objective: In Japan, public health nurses (PHNs) play important roles in managing the 9 10 11 33 health of local residents, especially after a disaster. In this study, we assessed radiation 12 13 34 anxiety and the stress processing capacity of PHNs in the Fukushima Prefecture in 14 15 For peer review only 16 35 Japan, after the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS). 17 18 36 Methods: We conducted a questionnaire survey among the PHNs (n=430) in July of 19 20 21 37 2015 via mail by post. The questions included demographic factors (sex, age, and 22 23 38 employment position), knowledge about radiation, degree of anxiety about radiation at 24 25 39 26 the time of the FDNPS accident (and at present), by asking them to answer questions 27 28 40 about radiation, and the Sense of Coherence13 (SOC13). We classified the low and 29 30 41 high levels of anxiety by asking them to answer questions about radiation, and 31 32 33 42 compared the anxietynegative () group with the anxietypositive (+) group. 34 http://bmjopen.bmj.com/ 35 43 Results: Of the PHNs, 269 (62.6%) were classified in the anxiety () group and 161 36 37 38 44 (37.4%) were in the anxiety (+) group. When the multivariate logistic regression 39 40 45 analysis was conducted, the PHNs at the time of the accident (OR: 2.37, p=0.007), 41

42 on September 24, 2021 by guest. Protected copyright. 43 46 current general anxieties about radiation (OR: 3.56, p<0.001), current possession of 44 45 47 materials to obtain knowledge about radiation (OR: 2.11, p=0.006), and knowledge of 46 47 48 48 the childhood thyroid cancer increase after the Chernobyl accident (OR: 1.69, p=0.035) 49 50 49 were significantly associated with anxiety after the FDNPS accident. The mean SOC13 51 52 53 50 was 43.0±7.7, with no significant difference between anxiety () group and anxiety (+) 54 55 51 group (p=0.47). 56 57 58 59 3 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 4 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 52 Conclusions: Our study suggested that anxiety about radiation was associated with 7 8 53 materials and knowledge about radiation in the PHNs of Fukushima Prefecture four 9 10 11 54 years after the FDNPS accident. It is important for PHNs to obtain knowledge and 12 13 55 teaching materials about radiation, and radiation education programs for PHNs must be 14 15 For peer review only 16 56 established in areas that have nuclear facilities. 17 18 57 19 20 21 58 Keywords: public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power 22 23 59 Station, Sense of Coherence13 24 25 60 26 27 28 61 Strengths and limitations of this study 29 30 62 ・We could assess radiation anxiety and the stress processing capacity of PHNs in the 31 32 33 63 Fukushima Prefecture in Japan, after the accident at the FDNPS. 34 http://bmjopen.bmj.com/ 35 64 ・We believe that this study regarding the PHNs’ situation in the Fukushima Prefecture 36 37 38 65 four years after the FDNPS disaster will be very important in the provision of future 39 40 66 support. 41

42 on September 24, 2021 by guest. Protected copyright. 43 67 ・We could not obtain sufficient information on the anxietyrelated factors, such as 44 45 68 detailed consultation contents and other information. 46 47 48 69 ・We were not able to gather sufficient information on stress management factors, such 49 50 70 as family issues and marital status. 51 52 53 71 54 55 56 57 58 59 4 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 5 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 72 Introduction 7 8 73 On March 11, 2011, the Great East Japan Earthquake struck the east coast of 9 10 11 74 Japan. This large earthquake and tsunami caused immense damage, including that to the 12 13 75 Fukushima Daiichi Nuclear Power Station (FDNPS) [14]. After the accident at the 14 15 For peer review only 16 76 FDNPS, the Fukushima prefectural government immediately issued instructions for the 17 18 77 evacuation of those areas within a 20 km radius of the FDNPS, and they also instructed 19 20 21 78 sheltering in the areas between 20 km and 30 km from the FDNPS. Beyond the 30 km 22 23 79 radius, additional areas were designated “deliberate evacuation areas” if there was 24 25 80 26 concern that the cumulative doses of radiation might reach 20 mSv per year in those 27 28 81 areas [2]. Despite the low estimated and measured external and internal exposure doses 29 30 82 just after the accident, many residents of the Fukushima Prefecture evacuated inside or 31 32 33 83 outside the prefecture [58]. 34 http://bmjopen.bmj.com/ 35 84 In the report by the World Health Organization (WHO) on the health impacts 20 36 37 38 85 years after the Chernobyl accident, mental health was described as the most serious 39 40 86 public health problem resulting from that nuclear accident [911]. Based on the lessons 41

42 on September 24, 2021 by guest. Protected copyright. 43 87 learned from the Chernobyl accident, the Fukushima Health Management Survey 44 45 88 (FHMS) was initiated to assess the health impacts, including mental health, of the 46 47 48 89 residents by the Fukushima prefectural government and the Fukushima Medical 49 50 90 University [12, 13]. According to the results of this survey, the residents of the 51 52 53 91 Fukushima Prefecture were exposed to a higher risk of not only physical problems, such 54 55 92 as diabetes and obesity, but also mental problems (including the risk perception of the 56 57 58 59 5 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 6 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 93 health effects of radiation) [14, 15]. 7 8 94 In Japan, public health nurses (PHNs) hold a national license, and many PHNs 9 10 11 95 work for prefectural and municipal bodies, enabling them to provide community health 12 13 96 services such as health guidance, home visits, and health education to local residents. In 14 15 For peer review only 16 97 other words, they play important roles in managing the health of local residents, 17 18 98 including the time after this disaster. While they were themselves victims of the 19 20 21 99 radiation disaster, they had to respond to the residents’ anxieties about radiation 22 23 100 exposure, despite their lack of professional knowledge on this topic. 24 25 101 26 In this study, we conducted a survey to clarify the radiation anxiety and stress 27 28 102 processing capacity of the PHNs in the Fukushima Prefecture, after the nuclear accident 29 30 103 at the FDNPS. 31 32 33 104 34 http://bmjopen.bmj.com/ 35 105 Materials and Methods 36 37 38 106 Study population and data collection 39 40 107 We conducted a questionnaire survey among the PHNs in the Fukushima 41

42 on September 24, 2021 by guest. Protected copyright. 43 108 Prefecture located in Northeastern Japan, which was severely affected by the earthquake, 44 45 109 tsunami, and FDNPS accident following the Great East Japan Earthquake in 2011. The 46 47 48 110 survey was conducted in July of 2015 via mail by post, and contained questions about 49 50 111 the demographic factors (sex, age, activity area, and employment position) and 51 52 53 112 knowledge of the PHNs about radiation before and after the accident at the FDNPS, and 54 55 113 their mental health status. In addition, we examined their degree of anxiety about 56 57 58 59 6 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 7 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 114 radiation at the time of the FDNPS accident, and at present, by asking them to answer 7 8 115 questions about radiation at present. The degree of anxiety was rated on a 10point 9 10 11 116 Likert scale ranging from no anxiety to having a lot of anxiety; we defined 15 as 12 13 117 “anxiety ()” and 610 as “anxiety (+).” 14 15 For peer review only 16 118 To measure the PHNs’ stress management capability, we used the Japanese 17 18 119 version of the Sense of Coherence13 (SOC13). The SOC13 consists of three 19 20 21 120 dimensions (comprehensibility, manageability, and meaningfulness) that are equally 22 23 121 weighted to create an overall (total) score. The score ranges from 791, with a higher 24 25 122 26 score representing a stronger sense of coherence [16]. 27 28 123 29 30 124 Statistical analysis 31 32 33 125 We classified the low and high levels of anxiety by asking them to answer 34 http://bmjopen.bmj.com/ 35 126 questions about radiation, and compared the anxiety () group and anxiety (+) group by 36 37 38 127 using the chisquare test and ttest as univariate analyses. A multiple logistic regression 39 40 128 analysis was then used to calculate the odds ratio (OR), and its 95% confidence interval 41

42 on September 24, 2021 by guest. Protected copyright. 43 129 (95% CI) was used to identify the factors independently associated with the anxiety 44 45 130 level. A pvalue of less than 0.05 was considered to be significant, and the statistical 46 47 48 131 analysis was performed using SPSS Statistics 22.0 (IBM Japan, Tokyo, Japan). 49 50 132 51 52 53 133 Ethics statement 54 55 134 This study was approved by the ethics committee of the Fukushima Medical 56 57 58 59 7 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 8 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 135 University (No. 2251), and conducted in accordance with the guidelines specified in the 7 8 136 Declaration of Helsinki. 9 10 11 137 12 13 14 15 For peer review only 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 8 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 9 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 138 Results 7 8 139 A total of 458 PHNs responded to the survey, and 430 of those PHNs (93.9%) 9 10 11 140 completed all of the questions. The number of women was 416 (96.7%), and 153 12 13 141 (35.6%) were 50 years old or older. The number of PHNs with less than 10 years of 14 15 For peer review only 16 142 working experience was 124 (22.8%), and 306 (71.2%) had ten years or more. There 17 18 143 were 119 participants (27.7%) with managerial positions. At the time of the accident, 19 20 21 144 330 (76.8%) worked as PHNs and 62 (14.4%) were still in training. The number of 22 23 145 those in Hamadori, which became the evacuation area of the FDNPS accident, was 83 24 25 146 26 (19.3%) (Table 1). 27 28 147 29 30 148 Table 1. Basic characteristics of the study participants. 31 32 33 Variable Number (%) 34 http://bmjopen.bmj.com/ 35 Gender Women 416(96.7) 36 Men 14(3.3) 37 38 Age 2029 years old 92(21.4) 39 3039 years old 72(16.7) 40 4049 years old 113(26.3) 41 ≥50 years old 153(35.6) 42 on September 24, 2021 by guest. Protected copyright. 43 Tenure as a public health nurse <10 years 124(28.8) 44 ≥10 years 306(71.2) 45 Nursing experience in a hospital Yes 149(34.7) 46 No 281(65.3) 47 Activity area Hamadori 83(19.3) 48 49 Other area (Nakadori, Aizu et al.) 347(80.7) 50 Position in the workplace Manager (director, chief) 119(27.7) 51 Staff 311(72.3) 52 Occupation at the time of the Public health nurse 330(76.8) 53 54 accident Other occupations (mostly nurses) 38(8.8) 55 Students 62(14.4) 56 57 149 58 59 9 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 10 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 150 Of the PHNs, 269 were classified in the anxiety () group and 161 were in the 7 8 151 anxiety (+) group (Table 2). A significantly higher ratio of PHNs younger than 40 years 9 10 11 152 old was observed in the anxiety (+) group (p<0.001, Table 2). Likewise, higher ratios of 12 13 153 PHNs with less than 10 years of working experience, staff positions, and nursing 14 15 For peer review only 16 154 licenses were observed in the anxiety (+) group (p<0.001, respectively, Table 2). On the 17 18 155 other hand, no significant differences were observed between the two groups in the 19 20 21 156 activity area, education curriculum, and seminars before or after the accident (p=0.62, 22 23 157 p=0.16, p=0.60, and p=0.13, respectively, Table 2). In addition, there was no significant 24 25 158 26 difference in the mean points in the SOC13 observed between the two groups (p=0.47, 27 28 159 Table 2). 29 30 160 31 32 33 161 Table 2. Participant’s demographic factors, educational history, and mental health 34 http://bmjopen.bmj.com/ 35 162 via anxiety with regard to questions about radiation after the FNPS accident. 36 37 38 Anxiety () Anxiety (+) 39 Variable Unit pvalues 40 (n=269) (%) (n=161) (%) 41

42 Gender Women/ 262(97.4)/ 154(95.7)/ on September 24, 2021 by guest. Protected copyright. 0.32 43 Men 7(2.6) 7(4.3) 44 Age <40 years old/ 77(28.6)/ 87(54.0)/ 45 <0.001 46 ≥40 years old 192(71.4) 74(46.0) 47 Working experience as a public <10 years/ 53(19.7)/ 71(44.1)/ <0.001 48 health nurse ≥10 years 216(80.3) 90(55.9) 49 Activity area Hamadori/ 54(20.1)/ 29(18.0)/ 50 0.62 51 Other area 215(79.9) 132(72.0) 52 Position in the workplace Manager/ 88(32.7)/ 31(19.3)/ 0.003 53 Staff 181(67.3) 130(80.7) 54 Occupation at the time of the PHNs/ 55 230(85.5)/ 100(62.1)/ accident Others (nurses, <0.001 56 39(14.5) 61(37.9) 57 students) 58 59 10 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 11 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 Did you have children ≤15 6 years old at the time of the Yes 110(40.9) 59(36.6) 0.42 7 8 accident? 9 Education history in Yes 114(42.4) 80(49.7) 0.16 10 curriculum 11 Education history in seminar 12 Yes 25(9.3) 12(7.5) 0.60 13 before the accident 14 Education history in seminar Yes 247(91.8) 140(87.0) 0.13 15 after the accidentFor peer review only 16 Frequency of participation in Once/ 47(19.0)/ 42(29.6)/ 17 0.02 18 seminars Plural 200(81.0) 98(70.4) 19 SOC13 total points Mean 44.0 41.4 0.47 20 21 163 22 23 164 In the anxiety (+) group, the ratio of those having current anxiety about radiation 24 25 26 165 was significantly higher than that in the anxiety () group (p<0.001, Table 3). On the 27 28 166 other hand, in the anxiety () group, the ratios with difficulty answering the questions 29 30 167 about radiation, currently having the materials to obtain knowledge about radiation, and 31 32 33 168 having knowledge about childhood thyroid cancer increases after the Chernobyl 34 http://bmjopen.bmj.com/ 35 169 accident were significantly higher than in the anxiety (+) group (p<0.05, p<0.01, and 36 37 38 170 p<0.05, respectively, Table 3). However, there were no significant changes between the 39 40 171 two groups in the anxiety about radiation at the time of the accident and the recognition 41

42 on September 24, 2021 by guest. Protected copyright. 43 172 of health effects (such as late effects and genetic effects) due to radiation exposure 44 45 173 (p=0.68, p=0.79, and p=0.20, respectively, Table 3). 46 47 48 174 49 50 175 Table 3. Participants’ anxiety, recognition, and knowledge about radiation via 51 52 53 176 anxiety with regard to answering the questions about radiation after the FDNPS 54 55 177 accident. 56 57 58 59 11 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 12 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 Anxiety () Anxiety (+) 7 Question Unit pvalues 8 (n=269) (%) (n=161) (%) 9 10 Degree of anxiety about radiation at anxiety ()/ 99(36.8)/ 56(34.8)/ 11 0.68 the time of the FDNPS accident anxiety (+) 170(63.2) 105(65.2) 12 Degree of anxiety about radiation anxiety ()/ 251(93.3)/ 130(80.7)/ 13 <0.001 14 currently anxiety (+) 18(6.7) 31(19.3) 15 Do you thinkFor that delayed peer effects such review only 16 as malignancies occur due to radiation 17 Yes 37(13.8) 33(20.5) 0.79 18 exposure following the Fukushima 19 accident? 20 Do you think that genetic effects in 21 offspring occur due to radiation 22 Yes 33(12.3) 27(16.8) 0.20 23 exposure following the Fukushima 24 accident? 25 Did you have a difficult time 26 answering the questions about Yes 216(80.3) 115(71.4) 0.04 27 radiation? 28 29 Did you have the materials to obtain 30 knowledge about radiation at the time Yes 87(32.3) 40(24.8) 0.10 31 of the accident? 32 Do you currently have the materials to 33 Yes 233(86.6) 118(73.3) 0.01 34 obtain knowledge about radiation? http://bmjopen.bmj.com/ Did you know about the three 35 Yes 64(23.8) 42(26.1) 0.64 36 principles of radiation protection? 37 Did you know about the annual dose 38 Yes 20(12.4) 11(6.8) 0.99 39 limit for the general public? Did you know about the halflife of 40 Yes 129(48.0) 77(47.8) 0.99 41 radioactive substances? 42 Did you know about childhood on September 24, 2021 by guest. Protected copyright. 43 thyroid cancer increases after the Yes 213(79.2) 109(67.7) 0.01 44 45 Chernobyl accident? 46 47 178 48 49 179 When the logistic regression analysis was conducted, following the adjustment 50 51 180 for confounding factors, being a PHN at the time of the accident (OR: 2.37, p<0.01), 52 53 54 181 current general anxieties about radiation (OR: 3.56, p<0.001), currently having the 55 56 182 materials to obtain knowledge about radiation (OR: 2.11, p<0.01), and having 57 58 59 12 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 13 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 183 knowledge about childhood thyroid cancer increases after the Chernobyl accident (OR: 7 8 184 1.69, p=0.04) were all significantly associated with anxiety after the FDNPS accident 9 10 11 185 (Table 4). 12 13 186 14 15 For peer review only 16 187 Table 4. Odds ratios and 95% confidence intervals of the study variables for 17 18 188 anxiety (+) by asking them to answer questions about radiation, as assessed by the 19 20 21 189 logistic regression analysis. 22 95% confidence 23 Variable Unit Odds ratio pvalue 24 interval 25 Age ≥40 years old 0.64 0.361.15 0.13 26 Manager in the No 1.14 0.652.00 0.66 27 workplace 28 Public health nurse at 29 No 2.37 1.274.42 <0.01 30 the time of the accident 31 Current degree of anxiety (+) 3.56 1.826.96 <0.001 32 anxiety about radiation 33 34 Difficulty answering http://bmjopen.bmj.com/ 35 radiation questions in No 1.27 0.762.12 0.37 36 the past 37 Currently have 38 materials to obtain 39 No 2.11 1.2483.60 <0.01 40 knowledge about 41 radiation 42 Knowledge about on September 24, 2021 by guest. Protected copyright. 43 childhood thyroid 44 No 1.69 1.042.75 0.04 45 cancer increase after the 46 Chernobyl accident 47 190 48 49 50 51 52 53 54 55 56 57 58 59 13 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 14 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 191 Discussion 6 7 192 This study was conducted four years after the FDNPS disaster to provide 8 9 10 193 educational support for PHNs who receive many consultations from residents. In 11 12 194 univariate analysis, younger and inexperienced PHNs had higher anxiety with regard to 13 14 195 communicating with residents about radiation. When adjusting for other variables, those 15 For peer review only 16 17 196 PHNs who were students at the time of the accident had higher anxiety when 18 19 197 communicating with residents about radiation. Our results suggested that experience as 20 21 22 198 a professional during the FDNPS accident is important. Although many of the PHNs 23 24 199 had knowledge about the Chernobyl accident, they could not properly communicate the 25 26 27 200 health effects of radiation with the residents, which caused anxiety in the residents after 28 29 201 the accident at the FDNPS. In addition, our results showed that having the materials to 30 31 32 202 obtain knowledge about radiation was independently associated with anxiety about the 33 34 203 FDNPS accident. http://bmjopen.bmj.com/ 35 36 37 204 These results suggest that continuous effort is necessary to provided education 38 39 205 and materials among the PHNs in the Fukushima Prefecture for them to gain knowledge 40 41 206 about radiation, including the health effects caused by radiation exposure [17]. Some 42 on September 24, 2021 by guest. Protected copyright. 43 44 207 education initiatives have been undertaken in the prefecture after the nuclear accident, 45 46 208 which includes Fukushima Medical University’s disaster education for undergraduates 47 48 49 209 and health literacy training for public health nurses for field practitioners [18, 19]. 50 51 210 Appropriate and sustainable allocation of financial and human resources is needed to 52 53 54 211 continue and expand such activities. 55 56 212 The SOC13 was employed to estimate the stress management capability of the 57 58 59 14 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 15 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 213 PHNs in this study. There was no significant difference in the mean points in the 7 8 214 SOC13 observed between the anxiety () group and anxiety (+) group. This result, as 9 10 11 215 well as other study, may suggest that factor of lifestyle related [20]. On the other hand, 12 13 216 Eriksson et al. showed that individuals with high scores in the SOC13 are better able to 14 15 For peer review only 16 217 cope with chronic stress than those with low scores [21]. In other studies, the average 17 18 218 points of the nursing students at two Japanese universities were 50.2±7.7 and 53.8±10.7, 19 20 21 219 respectively [22, 23], and the average score of elderly individuals in the Nagasaki 22 23 220 Prefecture in Japan was 45.0 [24]. In this study, the average score (43.0±7.7) was lower 24 25 221 26 than those in other studies, and it was substantially lower when compared to those of 27 28 222 nursing students. Accordingly, there is a need for planning of stress management 29 30 223 capacity improvement for the PHNs in Fukushima Prefecture with low SOC score. 31 32 33 224 The correspondence of the disaster affected the stress management capability, and 34 http://bmjopen.bmj.com/ 35 225 might cause a worsening of chronic stress. According to the FHMS, which includes 36 37 38 226 monitoring the mental health and daily lives of Fukushima residents and providing 39 40 227 proper care for them, the mental health status of the residents in the Fukushima 41

42 on September 24, 2021 by guest. Protected copyright. 43 228 Prefecture was very poor [13]. Thus, the mental health of the residents was greatly 44 45 229 affected by the disaster, and a similar impact could be expected from the PHNs who 46 47 48 230 work in the Fukushima Prefecture. Therefore, mental support is important for the PHNs, 49 50 231 as well as for the residents of the Fukushima Prefecture. 51 52 53 232 The present study has several limitations. First, we could not obtain sufficient 54 55 233 information on the anxietyrelated factors, such as detailed consultation contents and 56 57 58 59 15 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 16 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 234 other information. Second, we were not able to gather sufficient information on stress 7 8 235 management factors, such as family issues and marital status. However, we believe that 9 10 11 236 this study regarding the PHNs’ situation in the Fukushima Prefecture four years after the 12 13 237 FDNPS disaster will be very important in the provision of future support. 14 15 For peer review only 16 238 In conclusion, we conducted a survey of the radiation anxiety and stress 17 18 239 processing capacity of PHNs in the Fukushima Prefecture four years after the nuclear 19 20 21 240 accident at the FDNPS, and determined that it is important for PHNs to obtain 22 23 241 knowledge and teaching materials about radiation. In order to develop workers’ 24 25 242 26 capabilities that can correspond to the timing of radiation disasters in the future, 27 28 243 radiation education programs for PHNs and nursing students must be established in 29 30 244 areas that have nuclear power stations and other nuclear facilities. 31 32 33 245 34 http://bmjopen.bmj.com/ 35 246 Footnotes 36 37 38 247 Contributorship statement 39 40 248 ・Koji Yoshida conceived and designed the experiments, analyzed the data, wrote the 41

42 on September 24, 2021 by guest. Protected copyright. 43 249 paper, prepared Tables. 44 45 250 ・Makiko Orita, Akira Ohtsuru, Aya Goto, Atsushi Kumagai and Kiyotaka Yasui 46 47 48 251 contributed materials, reviewed drafts of the paper. 49 50 252 ・Naomi Hayashida, Takashi Kudo, and Shunichi Yamashita designed the experiments, 51 52 53 253 reviewed drafts of the paper. 54 55 254 • Noboru Takamura conceived and designed the experiments, wrote the paper, 56 57 58 59 16 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 17 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 255 reviewed drafts of the paper. 7 8 256 9 10 11 257 Competing interests 12 13 258 There are no competing interests 14 15 For peer review only 16 259 17 18 260 Funding 19 20 21 261 This study was partly supported by Japan Society for Promotion of Science. 22 23 262 24 25 26 263 Data sharing statement 27 28 264 No additional data are available. 29 30 265 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 17 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 18 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 266 6 267 7 References 8 268 1. United Nations Scientific Committee on the Effects of Atomic Radiation. 9 10 11 269 UNSCEAR 2013 Report Volume I Report to the general assembly scientific 12 13 270 annex A: Levels and effects of radiation exposure due to the nuclear accident 14 15 For peer review only 16 271 after the 2011 Great eastJapan earthquake and tsunami. Available: 17 18 272 http://www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf 19 20 21 273 (accessed 16 July 2016). 22 23 274 2. International Atomic Energy Agency. The Fukushima Daiichi accident Technical 24 25 275 26 Volume 4. Radiological Consequences. Vienna: International Atomic Energy 27 28 276 Agency (IAEA). 2015: 1250. 29 30 277 3. Nuclear Emergency Response Headquarters of Japanese Government. Report of 31 32 33 278 Japanese government to the IAEA ministerial conference on nuclear safety. The 34 http://bmjopen.bmj.com/ 35 279 Accident at TEPCO’s Fukushima nuclear power stations. Available: 36 37 38 280 http://japan.kantei.go.jp/kan/topics/201106/iaea_houkokusho_e.html (accessed 39 40 281 16 July 2016). 41

42 on September 24, 2021 by guest. Protected copyright. 43 282 4. Nuclear Emergency Response Headquarters of Japanese Government. Additional 44 45 283 report of the Japanese government to the IAEA—The Accident at TEPCO’s 46 47 48 284 Fukushima nuclear power stations (Second Report). Available: 49 50 285 https://www.iaea.org/newscenter/focus/fukushima/additionaljapanreport 51 52 53 286 (accessed 16 July 2016). 54 55 287 5. Nagataki S, Takamura N, Kamiya K, et al. Measurements of individual radiation 56 57 58 59 18 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 19 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 288 doses in residents living around the Fukushima Nuclear Power Plant. Rad Res. 7 8 289 2013;180: 439447. doi: 10.1667/RR13351.1 9 10 11 290 6. Nagataki S, Takamura N. A review of the Fukushima nuclear reactor accident: 12 13 291 radiation effects on the thyroid and strategies for prevention. Curr Opin 14 15 For peer review only 16 292 Endocrinol Diabetes Obes. 2014;21: 384393. doi: 17 18 293 10.1097/MED.0000000000000098 19 20 21 294 7. Ishikawa T, Yasumura S, Ozasa K, et al. The Fukushima Health Management 22 23 295 Survey: estimation of external doses to residents in Fukushima Prefecture. Sci 24 25 296 26 Rep. 2015;5: 12712. 111. doi: 10.1038/srep12712 27 28 297 8. Yoshida K, Hashiguchi K, Taira Y, et al. Importance of personal dose equivalent 29 30 298 evaluation in Fukushima in overcoming social panic. Radiat Prot Dosimetry. 31 32 33 299 2012;151(1): 1446. doi: 10.1093/rpd/ncr466 34 http://bmjopen.bmj.com/ 35 300 9. WHO (World Health Organization) 2005a. Health Effects of the Chernobyl 36 37 38 301 Accident and Special Health Care Programmes. Available: 39 40 302 http://www.who.int/ionizing_radiation/a_e/chernobyl/EGH%20Master%20file 41

42 on September 24, 2021 by guest. Protected copyright. 43 303 %202005.08.24.pdf. (accessed 16 July 2016). 44 45 304 10. WHO (World Health Organization) 2005b. Chernobyl: The true scale of the 46 47 48 305 accident; 20 Years Later a UN Report Provides Definitive Answers and Ways to 49 50 306 Repair Lives. Available: 51 52 53 307 http://www.who.int/mediacentre/news/releases/2005/pr38/en/ (accessed 16 July 54 55 308 2016). 56 57 58 59 19 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 20 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 309 11. WHO (World Health Organization). Health effects of the Chernobyl Accident 7 8 310 and Special Health Care Programmes. Geneva:WHO 2006. Available: 9 10 11 311 http://www.who.int/ionizing_radiation/chernobyl/who_chernobyl_report_2006.p 12 13 312 df#search=%2715.+WHO+%28World+Health+Organization%29.+Health+effect 14 15 For peer review only 16 313 s+of+the+Chernobyl+Accident+and+Special+Health+Car%27.pdf. (accessed 16 17 18 314 July 2016). 19 20 21 315 12. Yasumura S, Hosoya M, Yamashita S, et al. Study Protocol for the Fukushima 22 23 316 Health Management Survey. J Epidemiol. 2012;22: 375383. PMID: 22955043 24 25 317 26 13. Yabe H, Suzuki Y, Mashiko H, et al. Psychological distress after the Great East 27 28 318 Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident: results 29 30 319 of a mental health and lifestyle survey through the Fukushima Health 31 32 33 320 Management Survey in FY2011 and FY2012. Fukushima J Med Sci. 2014;60(1): 34 http://bmjopen.bmj.com/ 35 321 5767. PMID: 25030715 36 37 38 322 14. Ohira T, Hosoya M, Yasumura S, et al. Effect of Evacuation on Body Weight 39 40 323 After the Great East Japan Earthquake. Am J Prev Med. 2016;50(5): 55360. doi: 41

42 on September 24, 2021 by guest. Protected copyright. 43 324 10.1016/j.amepre.2015.10.008 44 45 325 15. Satoh H, Ohira T, Hosoya M, et al. Evacuation after the Fukushima Daiichi 46 47 48 326 Nuclear Power Plant Accident Is a Cause of Diabetes: Results from the 49 50 327 Fukushima Health Management Survey. J Diabetes Res. 2015: 627390. doi: 51 52 53 328 10.1155/2015/627390 54 55 329 16. Antonovsky A. The structure and properties of the sense of coherence scale. Soc 56 57 58 59 20 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 21 of 22 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 330 Sci Med. 1993;36(6): 72533. PMID: 8480217 7 8 331 17. Konishi E, Nagai T, Kobayashi M, et al. PostFukushima radiation education for 9 10 11 332 public health nursing students: a case study. Int Nurs Rev. 2016;63(2): 2929. 12 13 333 doi: 10.1111/inr.12244 14 15 For peer review only 16 334 18. Ohtsuru A, Tanigawa K, Kumagai A, et al. Nuclear disasters and health: lessons 17 18 335 learned, challenges, and proposals. Lancet. 2015;386(9992): 489497. doi: 19 20 21 336 http://dx.doi.org/10.1016/S01406736(15)609941 22 23 337 19. Goto A, Lai AY, Rudd RE. Health literacy training for public health nurses in 24 25 338 26 Fukushima: A multisite program evaluation. Japan Med Assoc J. 2015;58(3): 27 28 339 6977. PMID: 26870621 29 30 340 20. Wainwright NW, Surtees PG, Welch AA, et al. Healthy lifestyle choices: could 31 32 33 341 sense of coherence aid health promotion? J Epidemiol Community Health. 34 http://bmjopen.bmj.com/ 35 342 2007;61(10): 8716. doi: 10.1136/jech.2006.056275 36 37 38 343 21. Eriksson M, Lindström B. Antonovsky's sense of coherence scale and the 39 40 344 relation with health: a systematic review. J Epidemiol Community Health. 41

42 on September 24, 2021 by guest. Protected copyright. 43 345 2006;60(5): 37681. doi: 10.1136/jech.2005.041616 44 45 346 22. Ohki T, Ihara M. A nursing student demonstration in the adult nursing practice 46 47 48 347 and Sense of chherence (SOC). The Showa University journal of nursing and 49 50 348 rehabilitation sciences. 2013;11: 4348. (in Japanese) 51 52 53 349 23. Egami C. Relationship between sense of coherence and mental health at nursing 54 55 350 student. The Japan Society of Health Sciences of Mind and Body. 2008;4(2), 56 57 58 59 21 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 22 of 22 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 351 111116. (in Japanese) 7 8 352 24. Teraoka S, Hayashida N, Shinkawa T, et al. Good stress management capability 9 10 11 353 is associated with lower body mass index and restful sleep in the elderly. Tohoku 12 13 354 J Exp Med. 2013;229(1): 510. PMID: 23196278 14 15 For peer review only 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 22 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

Radiation-related Anxiety among Public Health Nurses in the Fukushima Prefecture after the Accident at the Fukushima Daiichi Nuclear Power Station：：： a cross-sectional study.

For peer review only Journal: BMJ Open

Manuscript ID bmjopen-2016-013564.R2

Article Type: Research

Date Submitted by the Author: 16-Sep-2016

Ohtsuru, Akira; Fukushima Medical University, Radiation Health http://bmjopen.bmj.com/ Management Hayashida, Naomi ; Atomic Bomb Disease Institute, Nagasaki University, Promotion of Collaborative Research on Radiation and Environment Health Effects Kudo, Takashi; Atomic Bomb Disease Institute, Nagasaki University, Radioisotope Medicine Yamashita, Shunichi ; Atomic Bomb Disease Institute, Nagasaki University, Radiation Medical Sciences Takamura, Noboru; Atomic Bomb Disease Institute, Nagasaki University, ; on September 24, 2021 by guest. Protected copyright.

Primary Subject Nursing Heading:

Secondary Subject Heading: Public health

public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power Keywords: Station, Sense of Coherence-13

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1 2 3 4 5 6 1 Radiation-related Anxiety among Public Health Nurses in the Fukushima 7 8 2 Prefecture after the Accident at the Fukushima Daiichi Nuclear Power Station: a 9 10 11 3 cross-sectional study. 12 13 4 14 15 For1,2* peer3 review4 only2 2 16 5 Koji Yoshida , Makiko Orita , Aya Goto , Atsushi Kumagai , Kiyotaka Yasui , Akira 17 18 6 Ohtsuru5, Naomi Hayashida6, Takashi Kudo7, Shunichi Yamashita8, Noboru Takamura3 19 20 21 7 22 23 8 1 Department of Health Sciences, Nagasaki University Graduate School of Biomedical 24 25 9 26 Sciences, Nagasaki, Japan 27 28 10 2 Education Center for Disaster Medicine, Fukushima Medical University, Fukushima, 29 30 11 Japan 31 32 33 12 3 Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, 34 http://bmjopen.bmj.com/ 35 13 Nagasaki University, Nagasaki, Japan 36 37 38 14 4 Center for Integrated Science and Humanities, Fukushima Medical University, 39 40 15 Fukushima, Japan 41

42 on September 24, 2021 by guest. Protected copyright. 43 16 5 Department of Radiation Health Management, Fukushima Medical University School 44 45 17 of Medicine, Fukushima, Japan 46 47 48 18 6 Division of Promotion of Collaborative Research on Radiation and Environment 49 50 19 Health Effects, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 51 52 53 20 7 Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki 54 55 21 University, Nagasaki, Japan 56 57 58 59 1 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 2 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 22 8 Department of, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 7 8 23 9 10 11 24 *Corresponding author 12 13 25 Koji Yoshida, R.N, Ph.D. 14 15 For peer review only 16 26 Department of Health Sciences, Nagasaki University Graduate School of Biomedical 17 18 27 Sciences, Nagasaki, Japan 19 20 21 28 171 Sakamoto, Nagasaki 8508520, Japan 22 23 29 Email: koujiy@nagasakiu.ac.jp (KY) 24 25 30 26 TEL: +81958197195 27 31 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 2 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 3 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 32 Abstract 7 8 33 Objective: In Japan, public health nurses (PHNs) play important roles in managing the 9 10 11 34 health of local residents, especially after a disaster. In this study, we assessed radiation 12 13 35 anxiety and the stress processing capacity of PHNs in the Fukushima Prefecture in 14 15 For peer review only 16 36 Japan, after the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS). 17 18 37 Methods: We conducted a questionnaire survey among the PHNs (n=430) in July of 19 20 21 38 2015 via mail by post. The questions included demographic factors (sex, age, and 22 23 39 employment position), knowledge about radiation, degree of anxiety about radiation at 24 25 40 26 the time of the FDNPS accident (and at present), by asking them to answer questions 27 28 41 about radiation, and the Sense of Coherence13 (SOC13). We classified the low and 29 30 42 high levels of anxiety by asking them to answer questions about radiation, and 31 32 33 43 compared the anxietynegative () group with the anxietypositive (+) group. 34 http://bmjopen.bmj.com/ 35 44 Results: Of the PHNs, 269 (62.6%) were classified in the anxiety () group and 161 36 37 38 45 (37.4%) were in the anxiety (+) group. When the multivariate logistic regression 39 40 46 analysis was conducted, the PHNs at the time of the accident (OR: 2.37, p=0.007), 41

42 on September 24, 2021 by guest. Protected copyright. 43 47 current general anxieties about radiation (OR: 3.56, p<0.001), current possession of 44 45 48 materials to obtain knowledge about radiation (OR: 2.11, p=0.006), and knowledge of 46 47 48 49 the childhood thyroid cancer increase after the Chernobyl accident (OR: 1.69, p=0.035) 49 50 50 were significantly associated with anxiety after the FDNPS accident. The mean SOC13 51 52 53 51 was 43.0±7.7, with no significant difference between anxiety () group and anxiety (+) 54 55 52 group (p=0.47). 56 57 58 59 3 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 4 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 53 Conclusions: Our study suggested that anxiety about radiation was associated with 7 8 54 materials and knowledge about radiation in the PHNs of Fukushima Prefecture four 9 10 11 55 years after the FDNPS accident. It is important for PHNs to obtain knowledge and 12 13 56 teaching materials about radiation, and radiation education programs for PHNs must be 14 15 For peer review only 16 57 established in areas that have nuclear facilities. 17 18 58 19 20 21 59 Keywords: public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power 22 23 60 Station, Sense of Coherence13 24 25 61 26 27 28 62 Strengths and limitations of this study 29 30 63 ・We could assess radiation anxiety and the stress processing capacity of PHNs in the 31 32 33 64 Fukushima Prefecture in Japan, after the accident at the FDNPS. 34 http://bmjopen.bmj.com/ 35 65 ・We believe that this study regarding the PHNs’ situation in the Fukushima Prefecture 36 37 38 66 four years after the FDNPS disaster will be very important in the provision of future 39 40 67 support. 41

42 on September 24, 2021 by guest. Protected copyright. 43 68 ・We could not obtain sufficient information on the anxietyrelated factors, such as 44 45 69 detailed consultation contents and other information. 46 47 48 70 ・We were not able to gather sufficient information on stress management factors, such 49 50 71 as family issues and marital status. 51 52 53 72 54 55 56 57 58 59 4 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 5 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 73 Introduction 7 8 74 On March 11, 2011, the Great East Japan Earthquake struck the east coast of 9 10 11 75 Japan. This large earthquake and tsunami caused immense damage, including that to the 12 13 76 Fukushima Daiichi Nuclear Power Station (FDNPS) [14]. After the accident at the 14 15 For peer review only 16 77 FDNPS, the Fukushima prefectural government immediately issued instructions for the 17 18 78 evacuation of those areas within a 20 km radius of the FDNPS, and they also instructed 19 20 21 79 sheltering in the areas between 20 km and 30 km from the FDNPS. Beyond the 30 km 22 23 80 radius, additional areas were designated “deliberate evacuation areas” if there was 24 25 81 26 concern that the cumulative doses of radiation might reach 20 mSv per year in those 27 28 82 areas [2]. Despite the low estimated and measured external and internal exposure doses 29 30 83 just after the accident, many residents of the Fukushima Prefecture evacuated inside or 31 32 33 84 outside the prefecture [58]. 34 http://bmjopen.bmj.com/ 35 85 In the report by the World Health Organization (WHO) on the health impacts 20 36 37 38 86 years after the Chernobyl accident, mental health was described as the most serious 39 40 87 public health problem resulting from that nuclear accident [911]. Based on the lessons 41

42 on September 24, 2021 by guest. Protected copyright. 43 88 learned from the Chernobyl accident, the Fukushima Health Management Survey 44 45 89 (FHMS) was initiated to assess the health impacts, including mental health, of the 46 47 48 90 residents by the Fukushima prefectural government and the Fukushima Medical 49 50 91 University [12, 13]. According to the results of this survey, the residents of the 51 52 53 92 Fukushima Prefecture were exposed to a higher risk of not only physical problems, such 54 55 93 as diabetes and obesity, but also mental problems (including the risk perception of the 56 57 58 59 5 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 6 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 94 health effects of radiation) [14, 15]. 7 8 95 In Japan, public health nurses (PHNs) hold a national license, and many PHNs 9 10 11 96 work for prefectural and municipal bodies, enabling them to provide community health 12 13 97 services such as health guidance, home visits, and health education to local residents. In 14 15 For peer review only 16 98 other words, they play important roles in managing the health of local residents, 17 18 99 including the time after this disaster. While they were themselves victims of the 19 20 21 100 radiation disaster, they had to respond to the residents’ anxieties about radiation 22 23 101 exposure, despite their lack of professional knowledge on this topic. 24 25 102 26 In this study, we conducted a survey to clarify the radiation anxiety and stress 27 28 103 processing capacity of the PHNs in the Fukushima Prefecture, after the nuclear accident 29 30 104 at the FDNPS. 31 32 33 105 34 http://bmjopen.bmj.com/ 35 106 Materials and Methods 36 37 38 107 Study population and data collection 39 40 108 We conducted a questionnaire survey among the PHNs in the Fukushima 41

42 on September 24, 2021 by guest. Protected copyright. 43 109 Prefecture located in Northeastern Japan, which was severely affected by the earthquake, 44 45 110 tsunami, and FDNPS accident following the Great East Japan Earthquake in 2011. We 46 47 48 111 initially distributed questionnaires to 509 PHNs, and we obtained responses from 458 49 50 112 PHNs (90.0%), after excluding 28 PHNs with insufficient responses. The survey was 51 52 53 113 conducted in July of 2015 via mail by post, and contained questions about the 54 55 114 demographic factors (sex, age, activity area, and employment position) and knowledge 56 57 58 59 6 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 7 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 115 of the PHNs about radiation before and after the accident at the FDNPS, and their 7 8 116 mental health status. In addition, we examined their degree of anxiety about radiation at 9 10 11 117 the time of the FDNPS accident, and at present, by asking them to answer questions 12 13 118 about radiation at present. The degree of anxiety was rated on a 10point Likert scale 14 15 For peer review only 16 119 ranging from no anxiety to having a lot of anxiety; we defined 15 as “anxiety ()” and 17 18 120 610 as “anxiety (+).” 19 20 21 121 To measure the PHNs’ stress management capability, we used the Japanese 22 23 122 version of the Sense of Coherence13 (SOC13). The SOC13 consists of three 24 25 123 26 dimensions (comprehensibility, manageability, and meaningfulness) that are equally 27 28 124 weighted to create an overall (total) score. The score ranges from 791, with a higher 29 30 125 score representing a stronger sense of coherence [16]. 31 32 33 126 34 http://bmjopen.bmj.com/ 35 127 Statistical analysis 36 37 38 128 We classified the low and high levels of anxiety by asking them to answer 39 40 129 questions about radiation, and compared the anxiety () group and anxiety (+) group by 41

42 on September 24, 2021 by guest. Protected copyright. 43 130 using the chisquare test and ttest as univariate analyses. A multiple logistic regression 44 45 131 analysis was then used to calculate the odds ratio (OR), and its 95% confidence interval 46 47 48 132 (95% CI) was used to identify the factors independently associated with the anxiety 49 50 133 level. A pvalue of less than 0.05 was considered to be significant, and the statistical 51 52 53 134 analysis was performed using SPSS Statistics 22.0 (IBM Japan, Tokyo, Japan). 54 55 135 56 57 58 59 7 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 8 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 136 Ethics statement 7 8 137 This study was approved by the ethics committee of the Fukushima Medical 9 10 11 138 University (No. 2251), and conducted in accordance with the guidelines specified in the 12 13 139 Declaration of Helsinki. 14 15 For peer review only 16 140 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 8 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 9 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 141 Results 7 8 142 A total of 458 PHNs responded to the survey, and 430 of those PHNs (93.9%) 9 10 11 143 completed all of the questions. The number of women was 416 (96.7%), and 153 12 13 144 (35.6%) were 50 years old or older. The number of PHNs with less than 10 years of 14 15 For peer review only 16 145 working experience was 124 (22.8%), and 306 (71.2%) had ten years or more. There 17 18 146 were 119 participants (27.7%) with managerial positions. At the time of the accident, 19 20 21 147 330 (76.8%) worked as PHNs and 62 (14.4%) were still in training. The number of 22 23 148 those in Hamadori, which became the evacuation area of the FDNPS accident, was 83 24 25 149 26 (19.3%) (Table 1). 27 28 150 29 30 151 Table 1. Basic characteristics of the study participants. 31 32 33 Variable Number (%) 34 http://bmjopen.bmj.com/ 35 Gender Women 416(96.7) 36 Men 14(3.3) 37 38 Age 2029 years old 92(21.4) 39 3039 years old 72(16.7) 40 4049 years old 113(26.3) 41 ≥50 years old 153(35.6) 42 on September 24, 2021 by guest. Protected copyright. 43 Tenure as a public health nurse <10 years 124(28.8) 44 ≥10 years 306(71.2) 45 Nursing experience in a hospital Yes 149(34.7) 46 No 281(65.3) 47 Activity area Hamadori 83(19.3) 48 49 Other area (Nakadori, Aizu et al.) 347(80.7) 50 Position in the workplace Manager (director, chief) 119(27.7) 51 Staff 311(72.3) 52 Occupation at the time of the Public health nurse 330(76.8) 53 54 accident Other occupations (mostly nurses) 38(8.8) 55 Students 62(14.4) 56 57 152 58 59 9 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 10 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 153 Of the PHNs, 269 were classified in the anxiety () group and 161 were in the 7 8 154 anxiety (+) group (Table 2). A significantly higher ratio of PHNs younger than 40 years 9 10 11 155 old was observed in the anxiety (+) group (p<0.001, Table 2). Likewise, higher ratios of 12 13 156 PHNs with less than 10 years of working experience, staff positions, and nursing 14 15 For peer review only 16 157 licenses were observed in the anxiety (+) group (p<0.001, respectively, Table 2). On the 17 18 158 other hand, no significant differences were observed between the two groups in the 19 20 21 159 activity area, education curriculum, and seminars before or after the accident (p=0.62, 22 23 160 p=0.16, p=0.60, and p=0.13, respectively, Table 2). In addition, there was no significant 24 25 161 26 difference in the mean points in the SOC13 observed between the two groups (p=0.47, 27 28 162 Table 2). 29 30 163 31 32 33 164 Table 2. Participant’s demographic factors, educational history, and mental health 34 http://bmjopen.bmj.com/ 35 165 via anxiety with regard to questions about radiation after the FNPS accident. 36 37 38 Anxiety () Anxiety (+) 39 Variable Unit pvalues 40 (n=269) (%) (n=161) (%) 41

42 Gender Women/ 262(97.4)/ 154(95.7)/ on September 24, 2021 by guest. Protected copyright. 0.32 43 Men 7(2.6) 7(4.3) 44 Age <40 years old/ 77(28.6)/ 87(54.0)/ 45 <0.001 46 ≥40 years old 192(71.4) 74(46.0) 47 Working experience as a public <10 years/ 53(19.7)/ 71(44.1)/ <0.001 48 health nurse ≥10 years 216(80.3) 90(55.9) 49 Activity area Hamadori/ 54(20.1)/ 29(18.0)/ 50 0.62 51 Other area 215(79.9) 132(72.0) 52 Position in the workplace Manager/ 88(32.7)/ 31(19.3)/ 0.003 53 Staff 181(67.3) 130(80.7) 54 Occupation at the time of the PHNs/ 55 230(85.5)/ 100(62.1)/ accident Others (nurses, <0.001 56 39(14.5) 61(37.9) 57 students) 58 59 10 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 11 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 Did you have children ≤15 6 years old at the time of the Yes 110(40.9) 59(36.6) 0.42 7 8 accident? 9 Education history in Yes 114(42.4) 80(49.7) 0.16 10 curriculum 11 Education history in seminar 12 Yes 25(9.3) 12(7.5) 0.60 13 before the accident 14 Education history in seminar Yes 247(91.8) 140(87.0) 0.13 15 after the accidentFor peer review only 16 Frequency of participation in Once/ 47(19.0)/ 42(29.6)/ 17 0.02 18 seminars Plural 200(81.0) 98(70.4) 19 SOC13 total points Mean 44.0 41.4 0.47 20 21 166 22 23 167 In the anxiety (+) group, the ratio of those having current anxiety about radiation 24 25 26 168 was significantly higher than that in the anxiety () group (p<0.001, Table 3). On the 27 28 169 other hand, in the anxiety () group, the ratios with difficulty answering the questions 29 30 170 about radiation, currently having the materials to obtain knowledge about radiation, and 31 32 33 171 having knowledge about childhood thyroid cancer increases after the Chernobyl 34 http://bmjopen.bmj.com/ 35 172 accident were significantly higher than in the anxiety (+) group (p<0.05, p<0.01, and 36 37 38 173 p<0.05, respectively, Table 3). However, there were no significant changes between the 39 40 174 two groups in the anxiety about radiation at the time of the accident and the recognition 41

42 on September 24, 2021 by guest. Protected copyright. 43 175 of health effects (such as late effects and genetic effects) due to radiation exposure 44 45 176 (p=0.68, p=0.79, and p=0.20, respectively, Table 3). 46 47 48 177 49 50 178 Table 3. Participants’ anxiety, recognition, and knowledge about radiation via 51 52 53 179 anxiety with regard to answering the questions about radiation after the FDNPS 54 55 180 accident. 56 57 58 59 11 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 12 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 Anxiety () Anxiety (+) 7 Question Unit pvalues 8 (n=269) (%) (n=161) (%) 9 10 Degree of anxiety about radiation at anxiety ()/ 99(36.8)/ 56(34.8)/ 11 0.68 the time of the FDNPS accident anxiety (+) 170(63.2) 105(65.2) 12 Degree of anxiety about radiation anxiety ()/ 251(93.3)/ 130(80.7)/ 13 <0.001 14 currently anxiety (+) 18(6.7) 31(19.3) 15 Do you thinkFor that delayed peer effects such review only 16 as malignancies occur due to radiation 17 Yes 37(13.8) 33(20.5) 0.79 18 exposure following the Fukushima 19 accident? 20 Do you think that genetic effects in 21 offspring occur due to radiation 22 Yes 33(12.3) 27(16.8) 0.20 23 exposure following the Fukushima 24 accident? 25 Did you have a difficult time 26 answering the questions about Yes 216(80.3) 115(71.4) 0.04 27 radiation? 28 29 Did you have the materials to obtain 30 knowledge about radiation at the time Yes 87(32.3) 40(24.8) 0.10 31 of the accident? 32 Do you currently have the materials to 33 Yes 233(86.6) 118(73.3) 0.01 34 obtain knowledge about radiation? http://bmjopen.bmj.com/ Did you know about the three 35 Yes 64(23.8) 42(26.1) 0.64 36 principles of radiation protection? 37 Did you know about the annual dose 38 Yes 20(12.4) 11(6.8) 0.99 39 limit for the general public? Did you know about the halflife of 40 Yes 129(48.0) 77(47.8) 0.99 41 radioactive substances? 42 Did you know about childhood on September 24, 2021 by guest. Protected copyright. 43 thyroid cancer increases after the Yes 213(79.2) 109(67.7) 0.01 44 45 Chernobyl accident? 46 47 181 48 49 182 When the logistic regression analysis was conducted, following the adjustment 50 51 183 for confounding factors, being a PHN at the time of the accident (OR: 2.37, p<0.01), 52 53 54 184 current general anxieties about radiation (OR: 3.56, p<0.001), currently having the 55 56 185 materials to obtain knowledge about radiation (OR: 2.11, p<0.01), and having 57 58 59 12 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 13 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 186 knowledge about childhood thyroid cancer increases after the Chernobyl accident (OR: 7 8 187 1.69, p=0.04) were all significantly associated with anxiety after the FDNPS accident 9 10 11 188 (Table 4). 12 13 189 14 15 For peer review only 16 190 Table 4. Odds ratios and 95% confidence intervals of the study variables for 17 18 191 anxiety (+) by asking them to answer questions about radiation, as assessed by the 19 20 21 192 logistic regression analysis. 22 95% confidence 23 Variable Unit Odds ratio pvalue 24 interval 25 Age ≥40 years old 0.64 0.361.15 0.13 26 Manager in the No 1.14 0.652.00 0.66 27 workplace 28 Public health nurse at 29 No 2.37 1.274.42 <0.01 30 the time of the accident 31 Current degree of anxiety (+) 3.56 1.826.96 <0.001 32 anxiety about radiation 33 34 Difficulty answering http://bmjopen.bmj.com/ 35 radiation questions in No 1.27 0.762.12 0.37 36 the past 37 Currently have 38 materials to obtain 39 No 2.11 1.2483.60 <0.01 40 knowledge about 41 radiation 42 Knowledge about on September 24, 2021 by guest. Protected copyright. 43 childhood thyroid 44 No 1.69 1.042.75 0.04 45 cancer increase after the 46 Chernobyl accident 47 193 48 49 50 51 52 53 54 55 56 57 58 59 13 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 14 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 194 Discussion 6 7 195 This study was conducted four years after the FDNPS disaster to provide 8 9 10 196 educational support for PHNs who receive many consultations from residents. In 11 12 197 univariate analysis, younger and inexperienced PHNs had higher anxiety with regard to 13 14 198 communicating with residents about radiation. When adjusting for other variables, those 15 For peer review only 16 17 199 PHNs who were students at the time of the accident had higher anxiety when 18 19 200 communicating with residents about radiation. Our results suggested that experience as 20 21 22 201 a professional during the FDNPS accident is important. Although many of the PHNs 23 24 202 had knowledge about the Chernobyl accident, they could not properly communicate the 25 26 27 203 health effects of radiation with the residents, which caused anxiety in the residents after 28 29 204 the accident at the FDNPS. In addition, our results showed that having the materials to 30 31 32 205 obtain knowledge about radiation was independently associated with anxiety about the 33 34 206 FDNPS accident. http://bmjopen.bmj.com/ 35 36 37 207 These results suggest that continuous effort is necessary to provided education 38 39 208 and materials among the PHNs in the Fukushima Prefecture for them to gain knowledge 40 41 209 about radiation, including the health effects caused by radiation exposure [17]. Some 42 on September 24, 2021 by guest. Protected copyright. 43 44 210 education initiatives have been undertaken in the prefecture after the nuclear accident, 45 46 211 which includes Fukushima Medical University’s disaster education for undergraduates 47 48 49 212 and health literacy training for public health nurses for field practitioners [18, 19]. 50 51 213 Appropriate and sustainable allocation of financial and human resources is needed to 52 53 54 214 continue and expand such activities. 55 56 215 The SOC13 was employed to estimate the stress management capability of the 57 58 59 14 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 15 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 216 PHNs in this study. There was no significant difference in the mean points in the 7 8 217 SOC13 observed between the anxiety () group and anxiety (+) group. This result, as 9 10 11 218 well as other study, may suggest that factor of lifestyle related [20]. On the other hand, 12 13 219 Eriksson et al. showed that individuals with high scores in the SOC13 are better able to 14 15 For peer review only 16 220 cope with chronic stress than those with low scores [21]. In other studies, the average 17 18 221 points of the nursing students at two Japanese universities were 50.2±7.7 and 53.8±10.7, 19 20 21 222 respectively [22, 23], and the average score of elderly individuals in the Nagasaki 22 23 223 Prefecture in Japan was 45.0 [24]. In this study, the average score (43.0±7.7) was lower 24 25 224 26 than those in other studies, and it was substantially lower when compared to those of 27 28 225 nursing students. Accordingly, there is a need for planning of stress management 29 30 226 capacity improvement for the PHNs in Fukushima Prefecture with low SOC score. 31 32 33 227 The correspondence of the disaster affected the stress management capability, and 34 http://bmjopen.bmj.com/ 35 228 might cause a worsening of chronic stress. According to the FHMS, which includes 36 37 38 229 monitoring the mental health and daily lives of Fukushima residents and providing 39 40 230 proper care for them, the mental health status of the residents in the Fukushima 41

42 on September 24, 2021 by guest. Protected copyright. 43 231 Prefecture was very poor [13]. Thus, the mental health of the residents was greatly 44 45 232 affected by the disaster, and a similar impact could be expected from the PHNs who 46 47 48 233 work in the Fukushima Prefecture. Therefore, mental support is important for the PHNs, 49 50 234 as well as for the residents of the Fukushima Prefecture. 51 52 53 235 The present study has several limitations. First, we could not obtain sufficient 54 55 236 information on the anxietyrelated factors, such as detailed consultation contents and 56 57 58 59 15 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 16 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 237 other information. Second, we were not able to gather sufficient information on stress 7 8 238 management factors, such as family issues and marital status. Third, this study might 9 10 11 239 have caused a recall bias on the study participants. However, we believe that this study 12 13 240 regarding the PHNs’ situation in the Fukushima Prefecture four years after the FDNPS 14 15 For peer review only 16 241 disaster will be very important in the provision of future support. 17 18 242 In conclusion, we conducted a survey of the radiation anxiety and stress 19 20 21 243 processing capacity of PHNs in the Fukushima Prefecture four years after the nuclear 22 23 244 accident at the FDNPS, and determined that it is important for PHNs to obtain 24 25 245 26 knowledge and teaching materials about radiation. In order to develop workers’ 27 28 246 capabilities that can correspond to the timing of radiation disasters in the future, 29 30 247 radiation education programs for PHNs and nursing students must be established in 31 32 33 248 areas that have nuclear power stations and other nuclear facilities. 34 http://bmjopen.bmj.com/ 35 249 36 37 38 250 Footnotes 39 40 251 Contributorship statement 41

42 on September 24, 2021 by guest. Protected copyright. 43 252 ・Koji Yoshida conceived and designed the experiments, analyzed the data, wrote the 44 45 253 paper, prepared Tables. 46 47 48 254 ・Makiko Orita, Akira Ohtsuru, Aya Goto, Atsushi Kumagai and Kiyotaka Yasui 49 50 255 contributed materials, reviewed drafts of the paper. 51 52 ・ 53 256 Naomi Hayashida, Takashi Kudo, and Shunichi Yamashita designed the experiments, 54 55 257 reviewed drafts of the paper. 56 57 58 59 16 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 17 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 258 • Noboru Takamura conceived and designed the experiments, wrote the paper, 7 8 259 reviewed drafts of the paper. 9 10 11 260 12 13 261 Competing interests 14 15 For peer review only 16 262 There are no competing interests 17 18 263 19 20 21 264 Funding 22 23 265 This study was partly supported by Japan Society for Promotion of Science. 24 25 26 266 27 28 267 Data sharing statement 29 30 268 No additional data are available. 31 32 269 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 17 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 18 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 270 6 271 7 References 8 272 1. United Nations Scientific Committee on the Effects of Atomic Radiation. 9 10 11 273 UNSCEAR 2013 Report Volume I Report to the general assembly scientific 12 13 274 annex A: Levels and effects of radiation exposure due to the nuclear accident 14 15 For peer review only 16 275 after the 2011 Great eastJapan earthquake and tsunami. Available: 17 18 276 http://www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf 19 20 21 277 (accessed 16 July 2016). 22 23 278 2. International Atomic Energy Agency. The Fukushima Daiichi accident Technical 24 25 279 26 Volume 4. Radiological Consequences. Vienna: International Atomic Energy 27 28 280 Agency (IAEA). 2015: 1250. 29 30 281 3. Nuclear Emergency Response Headquarters of Japanese Government. Report of 31 32 33 282 Japanese government to the IAEA ministerial conference on nuclear safety. The 34 http://bmjopen.bmj.com/ 35 283 Accident at TEPCO’s Fukushima nuclear power stations. Available: 36 37 38 284 http://japan.kantei.go.jp/kan/topics/201106/iaea_houkokusho_e.html (accessed 39 40 285 16 July 2016). 41

42 on September 24, 2021 by guest. Protected copyright. 43 286 4. Nuclear Emergency Response Headquarters of Japanese Government. Additional 44 45 287 report of the Japanese government to the IAEA—The Accident at TEPCO’s 46 47 48 288 Fukushima nuclear power stations (Second Report). Available: 49 50 289 https://www.iaea.org/newscenter/focus/fukushima/additionaljapanreport 51 52 53 290 (accessed 16 July 2016). 54 55 291 5. Nagataki S, Takamura N, Kamiya K, et al. Measurements of individual radiation 56 57 58 59 18 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 19 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 292 doses in residents living around the Fukushima Nuclear Power Plant. Rad Res. 7 8 293 2013;180: 439447. doi: 10.1667/RR13351.1 9 10 11 294 6. Nagataki S, Takamura N. A review of the Fukushima nuclear reactor accident: 12 13 295 radiation effects on the thyroid and strategies for prevention. Curr Opin 14 15 For peer review only 16 296 Endocrinol Diabetes Obes. 2014;21: 384393. doi: 17 18 297 10.1097/MED.0000000000000098 19 20 21 298 7. Ishikawa T, Yasumura S, Ozasa K, et al. The Fukushima Health Management 22 23 299 Survey: estimation of external doses to residents in Fukushima Prefecture. Sci 24 25 300 26 Rep. 2015;5: 12712. 111. doi: 10.1038/srep12712 27 28 301 8. Yoshida K, Hashiguchi K, Taira Y, et al. Importance of personal dose equivalent 29 30 302 evaluation in Fukushima in overcoming social panic. Radiat Prot Dosimetry. 31 32 33 303 2012;151(1): 1446. doi: 10.1093/rpd/ncr466 34 http://bmjopen.bmj.com/ 35 304 9. WHO (World Health Organization) 2005a. Health Effects of the Chernobyl 36 37 38 305 Accident and Special Health Care Programmes. Available: 39 40 306 http://www.who.int/ionizing_radiation/a_e/chernobyl/EGH%20Master%20file 41

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1 2 3 4 5 6 313 11. WHO (World Health Organization). Health effects of the Chernobyl Accident 7 8 314 and Special Health Care Programmes. Geneva:WHO 2006. Available: 9 10 11 315 http://www.who.int/ionizing_radiation/chernobyl/who_chernobyl_report_2006.p 12 13 316 df#search=%2715.+WHO+%28World+Health+Organization%29.+Health+effect 14 15 For peer review only 16 317 s+of+the+Chernobyl+Accident+and+Special+Health+Car%27.pdf. (accessed 16 17 18 318 July 2016). 19 20 21 319 12. Yasumura S, Hosoya M, Yamashita S, et al. Study Protocol for the Fukushima 22 23 320 Health Management Survey. J Epidemiol. 2012;22: 375383. PMID: 22955043 24 25 321 26 13. Yabe H, Suzuki Y, Mashiko H, et al. Psychological distress after the Great East 27 28 322 Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident: results 29 30 323 of a mental health and lifestyle survey through the Fukushima Health 31 32 33 324 Management Survey in FY2011 and FY2012. Fukushima J Med Sci. 2014;60(1): 34 http://bmjopen.bmj.com/ 35 325 5767. PMID: 25030715 36 37 38 326 14. Ohira T, Hosoya M, Yasumura S, et al. Effect of Evacuation on Body Weight 39 40 327 After the Great East Japan Earthquake. Am J Prev Med. 2016;50(5): 55360. doi: 41

42 on September 24, 2021 by guest. Protected copyright. 43 328 10.1016/j.amepre.2015.10.008 44 45 329 15. Satoh H, Ohira T, Hosoya M, et al. Evacuation after the Fukushima Daiichi 46 47 48 330 Nuclear Power Plant Accident Is a Cause of Diabetes: Results from the 49 50 331 Fukushima Health Management Survey. J Diabetes Res. 2015: 627390. doi: 51 52 53 332 10.1155/2015/627390 54 55 333 16. Antonovsky A. The structure and properties of the sense of coherence scale. Soc 56 57 58 59 20 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 21 of 24 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 334 Sci Med. 1993;36(6): 72533. PMID: 8480217 7 8 335 17. Konishi E, Nagai T, Kobayashi M, et al. PostFukushima radiation education for 9 10 11 336 public health nursing students: a case study. Int Nurs Rev. 2016;63(2): 2929. 12 13 337 doi: 10.1111/inr.12244 14 15 For peer review only 16 338 18. Ohtsuru A, Tanigawa K, Kumagai A, et al. Nuclear disasters and health: lessons 17 18 339 learned, challenges, and proposals. Lancet. 2015;386(9992): 489497. doi: 19 20 21 340 http://dx.doi.org/10.1016/S01406736(15)609941 22 23 341 19. Goto A, Lai AY, Rudd RE. Health literacy training for public health nurses in 24 25 342 26 Fukushima: A multisite program evaluation. Japan Med Assoc J. 2015;58(3): 27 28 343 6977. PMID: 26870621 29 30 344 20. Wainwright NW, Surtees PG, Welch AA, et al. Healthy lifestyle choices: could 31 32 33 345 sense of coherence aid health promotion? J Epidemiol Community Health. 34 http://bmjopen.bmj.com/ 35 346 2007;61(10): 8716. doi: 10.1136/jech.2006.056275 36 37 38 347 21. Eriksson M, Lindström B. Antonovsky's sense of coherence scale and the 39 40 348 relation with health: a systematic review. J Epidemiol Community Health. 41

42 on September 24, 2021 by guest. Protected copyright. 43 349 2006;60(5): 37681. doi: 10.1136/jech.2005.041616 44 45 350 22. Ohki T, Ihara M. A nursing student demonstration in the adult nursing practice 46 47 48 351 and Sense of chherence (SOC). The Showa University journal of nursing and 49 50 352 rehabilitation sciences. 2013;11: 4348. (in Japanese) 51 52 53 353 23. Egami C. Relationship between sense of coherence and mental health at nursing 54 55 354 student. The Japan Society of Health Sciences of Mind and Body. 2008;4(2), 56 57 58 59 21 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 22 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 355 111116. (in Japanese) 7 8 356 24. Teraoka S, Hayashida N, Shinkawa T, et al. Good stress management capability 9 10 11 357 is associated with lower body mass index and restful sleep in the elderly. Tohoku 12 13 358 J Exp Med. 2013;229(1): 510. PMID: 23196278 14 15 For peer review only 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

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1 2 STROBE Statement—Checklist of items that should be included in reports of cross-sectional studies 3 Item 4 No Recommendation 5 Title and abstract ✓1 (a) Indicate the study’s design with a commonly used term in the title or the 6

7 abstract Pages 1 and 3 8 (b) Provide in the abstract an informative and balanced summary of what was done 9 and what was found Page 3 10 Introduction 11 12 Background/rationale ✓2 Explain the scientific background and rationale for the investigation being reported 13 Pages 5-6 14 Objectives ✓3 State specific objectives, including any prespecified hypotheses Page 6 15 For peer review only 16 Methods 17 Study design ✓4 Present key elements of study design early in the paper Page 6 18 Setting ✓5 Describe the setting, locations, and relevant dates, including periods of recruitment, 19 exposure, follow-up, and data collection Page 6 20 21 Participants ✓6 (a) Give the eligibility criteria, and the sources and methods of selection of 22 participants Page 6 23 Variables ✓7 Clearly define all outcomes, exposures, predictors, potential confounders, and effect 24 modifiers. Give diagnostic criteria, if applicable Pages 7-8 25

26 Data sources/ ✓8* For each variable of interest, give sources of data and details of methods of 27 measurement assessment (measurement). Describe comparability of assessment methods if there 28 is more than one group Pages 6-7 29 Bias ✓9 Describe any efforts to address potential sources of bias Page 16 30 ✓ 31 Study size 10 Explain how the study size was arrived at Page 6 32 Quantitative variables ✓11 Explain how quantitative variables were handled in the analyses. If applicable, 33 describe which groupings were chosen and why Pages 7-8 http://bmjopen.bmj.com/ 34 Statistical methods ✓12 (a) Describe all statistical methods, including those used to control for confounding 35 Pages 7-8 b 36 ( ) Describe any methods used to examine subgroups and interactions 37 (c) Explain how missing data were addressed 38 (d) If applicable, describe analytical methods taking account of sampling strategy 39 (e) Describe any sensitivity analyses 40 41 Results

42 Participants ✓13* (a) Report numbers of individuals at each stage of study—eg numbers potentially on September 24, 2021 by guest. Protected copyright. 43 Pages 6 and 9 eligible, examined for eligibility, confirmed eligible, included in the study, 44 completing follow-up, and analysed 45 46 (b) Give reasons for non-participation at each stage 47 (c) Consider use of a flow diagram 48 Descriptive data ✓14* (a) Give characteristics of study participants (eg demographic, clinical, social) and 49 Pages 6 and 9 information on exposures and potential confounders 50 51 (b) Indicate number of participants with missing data for each variable of interest 52 Outcome data ✓15* Report numbers of outcome events or summary measures Pages 9-13 53 Main results ✓16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and 54 Table 4 their precision (eg, 95% confidence interval). Make clear which confounders were 55 56 adjusted for and why they were included 57 (b) Report category boundaries when continuous variables were categorized 58 (c) If relevant, consider translating estimates of relative risk into absolute risk for a 59 meaningful time period 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml1 BMJ Open Page 24 of 24 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 Other analyses ✓17 Report other analyses done—eg analyses of subgroups and interactions, and 3 sensitivity analyses Not applicable 4 Discussion 5 6 Key results ✓18 Summarise key results with reference to study objectives Page 14 7 Limitations ✓19 Discuss limitations of the study, taking into account sources of potential bias or 8 imprecision. Discuss both direction and magnitude of any potential bias Pages 16- 9 17 10 11 Interpretation ✓20 Give a cautious overall interpretation of results considering objectives, limitations, 12 multiplicity of analyses, results from similar studies, and other relevant evidence 13 Pages 16-17 14 Generalisability ✓21 Discuss the generalisability (external validity) of the study results Page 17 15 For peer review only 16 Other information 17 Funding ✓22 Give the source of funding and the role of the funders for the present study and, if 18 applicable, for the original study on which the present article is based Page 17 19 20 21 *Give information separately for exposed and unexposed groups. 22 23 Note: An Explanation and Elaboration article discusses each checklist item and gives methodological background and 24 published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely 25 26 available on the Web sites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at 27 http://www.annals.org/, and Epidemiology at http://www.epidem.com/). Information on the STROBE Initiative is 28 available at www.strobe-statement.org. 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

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Radiation-related Anxiety among Public Health Nurses in the Fukushima Prefecture after the Accident at the Fukushima Daiichi Nuclear Power Station：：： a cross-sectional study.

For peer review only Journal: BMJ Open

Manuscript ID bmjopen-2016-013564.R3

Article Type: Research

Date Submitted by the Author: 29-Sep-2016

Primary Subject Nursing Heading:

Secondary Subject Heading: Public health

public health nurse, anxiety, radiation, Fukushima Daiichi Nuclear Power Keywords: Station, Sense of Coherence-13

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42 on September 24, 2021 by guest. Protected copyright. 43 16 5 Department of Radiation Health Management, Fukushima Medical University School 44 45 17 of Medicine, Fukushima, Japan 46 47 48 18 6 Division of Promotion of Collaborative Research on Radiation and Environment 49 50 19 Health Effects, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan 51 52 53 20 7 Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki 54 55 21 University, Nagasaki, Japan 56 57 58 59 1 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 2 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

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42 on September 24, 2021 by guest. Protected copyright. 43 47 current general anxieties about radiation (OR: 3.56, p<0.001), current possession of 44 45 48 materials to obtain knowledge about radiation (OR: 2.11, p=0.006), and knowledge of 46 47 48 49 the childhood thyroid cancer increase after the Chernobyl accident (OR: 1.69, p=0.035) 49 50 50 were significantly associated with anxiety after the FDNPS accident. The mean SOC13 51 52 53 51 was 43.0±7.7, with no significant difference between anxiety () group and anxiety (+) 54 55 52 group (p=0.47). 56 57 58 59 3 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 4 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

42 on September 24, 2021 by guest. Protected copyright. 43 68 ・We could not obtain sufficient information on the anxietyrelated factors, such as 44 45 69 detailed consultation contents and other information. 46 47 48 70 ・We were not able to gather sufficient information on stress management factors, such 49 50 71 as family issues and marital status. 51 52 53 72 54 55 56 57 58 59 4 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 5 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

42 on September 24, 2021 by guest. Protected copyright. 43 88 learned from the Chernobyl accident, the Fukushima Health Management Survey 44 45 89 (FHMS) was initiated to assess the health impacts, including mental health, of the 46 47 48 90 residents by the Fukushima prefectural government and the Fukushima Medical 49 50 91 University [12, 13]. According to the results of this survey, the residents of the 51 52 53 92 Fukushima Prefecture were exposed to a higher risk of not only physical problems, such 54 55 93 as diabetes and obesity, but also mental problems (including the risk perception of the 56 57 58 59 5 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 6 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

42 on September 24, 2021 by guest. Protected copyright. 43 109 Prefecture located in Northeastern Japan, which was severely affected by the earthquake, 44 45 110 tsunami, and FDNPS accident following the Great East Japan Earthquake in 2011. We 46 47 48 111 initially distributed questionnaires to 509 PHNs, and we obtained responses from 458 49 50 112 PHNs (90.0%), after excluding 28 PHNs with insufficient responses. The survey was 51 52 53 113 conducted in July of 2015 via mail by post, and contained questions about the 54 55 114 demographic factors (sex, age, activity area, and employment position) and knowledge 56 57 58 59 6 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 7 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 115 of the PHNs about radiation before and after the accident at the FDNPS, and their 7 8 116 mental health status. In addition, we examined their degree of anxiety about radiation at 9 10 11 117 the time of the FDNPS accident, and at present, by asking them to answer questions 12 13 118 about radiation at present. The degree of anxiety was rated on a 10point Likert scale 14 15 For peer review only 16 119 ranging from no anxiety to having a lot of anxiety; we defined 15 as “anxiety ()” and 17 18 120 610 as “anxiety (+).” 19 20 21 121 To measure the PHNs’ stress management capability, we used the Japanese 22 23 122 version of the Sense of Coherence13 (SOC13). The SOC13 consists of three 24 25 123 26 dimensions (comprehensibility, manageability, and meaningfulness) that are equally 27 28 124 weighted to create an overall (total) score. Each question was rates on a 5point Likert 29 30 125 scale from one to five, with a higher score representing a stronger sense of coherence 31 32 33 126 (range:1365) [16]. 34 http://bmjopen.bmj.com/ 35 127 36 37 38 128 Statistical analysis 39 40 129 We classified the low and high levels of anxiety by asking them to answer 41

42 on September 24, 2021 by guest. Protected copyright. 43 130 questions about radiation, and compared the anxiety () group and anxiety (+) group by 44 45 131 using the chisquare test and ttest as univariate analyses. A multiple logistic regression 46 47 48 132 analysis was performed to assess the effects of each variable on the anxiety level 49 50 133 adjusted for confounding variables. In this study, the dependent variable was “the 51 52 53 134 anxiety (+) by asking them to answer questions about radiation,” the exposure variables 54 55 135 were “Manager in the workplace,” “Public health nurse at the time of the accident,” 56 57 58 59 7 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 8 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 136 “Current degree of anxiety about radiation,” “Difficulty answering radiation questions 7 8 137 in the past,” “Currently have materials to obtain knowledge about radiation,” and 9 10 11 138 “Knowledge about childhood thyroid cancer increase after the Chernobyl accident” and 12 13 139 the confounding variables was “age.” Odds ratio (ORs), and their 95% confidence 14 15 For peer review only 16 140 interval (95% CI) were also calculated. A pvalue of less than 0.05 was considered to be 17 18 141 significant, and the statistical analysis was performed using SPSS Statistics 22.0 (IBM 19 20 21 142 Japan, Tokyo, Japan). 22 23 143 24 25 26 144 Ethics statement 27 28 145 This study was approved by the ethics committee of the Fukushima Medical 29 30 146 University (No. 2251), and conducted in accordance with the guidelines specified in the 31 32 33 147 Declaration of Helsinki. 34 http://bmjopen.bmj.com/ 35 148 36 37 38 39 40 41

42 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 8 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 9 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 149 Results 7 8 150 A total of 458 PHNs responded to the survey, and 430 of those PHNs (93.9%) 9 10 11 151 completed all of the questions. The number of women was 416 (96.7%), and 153 12 13 152 (35.6%) were 50 years old or older. The number of PHNs with less than 10 years of 14 15 For peer review only 16 153 working experience was 124 (22.8%), and 306 (71.2%) had ten years or more. There 17 18 154 were 119 participants (27.7%) with managerial positions. At the time of the accident, 19 20 21 155 330 (76.8%) worked as PHNs and 62 (14.4%) were still in training. The number of 22 23 156 those in Hamadori, which became the evacuation area of the FDNPS accident, was 83 24 25 157 26 (19.3%) (Table 1). 27 28 158 29 30 159 Table 1. Basic characteristics of the study participants. 31 32 33 Variable Number (%) 34 http://bmjopen.bmj.com/ 35 Gender Women 416(96.7) 36 Men 14(3.3) 37 38 Age 2029 years old 92(21.4) 39 3039 years old 72(16.7) 40 4049 years old 113(26.3) 41 ≥50 years old 153(35.6) 42 on September 24, 2021 by guest. Protected copyright. 43 Tenure as a public health nurse <10 years 124(28.8) 44 ≥10 years 306(71.2) 45 Nursing experience in a hospital Yes 149(34.7) 46 No 281(65.3) 47 Activity area Hamadori 83(19.3) 48 49 Other area (Nakadori, Aizu et al.) 347(80.7) 50 Position in the workplace Manager (director, chief) 119(27.7) 51 Staff 311(72.3) 52 Occupation at the time of the Public health nurse 330(76.8) 53 54 accident Other occupations (mostly nurses) 38(8.8) 55 Students 62(14.4) 56 57 160 58 59 9 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 10 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 161 Of the PHNs, 269 were classified in the anxiety () group and 161 were in the 7 8 162 anxiety (+) group (Table 2). A significantly higher ratio of PHNs younger than 40 years 9 10 11 163 old was observed in the anxiety (+) group (p<0.001, Table 2). Likewise, higher ratios of 12 13 164 PHNs with less than 10 years of working experience, staff positions, and nursing 14 15 For peer review only 16 165 licenses were observed in the anxiety (+) group (p<0.001, respectively, Table 2). On the 17 18 166 other hand, no significant differences were observed between the two groups in the 19 20 21 167 activity area, education curriculum, and seminars before or after the accident (p=0.62, 22 23 168 p=0.16, p=0.60, and p=0.13, respectively, Table 2). In addition, there was no significant 24 25 169 26 difference in the mean points in the SOC13 observed between the two groups (p=0.47, 27 28 170 Table 2). 29 30 171 31 32 33 172 Table 2. Participant’s demographic factors, educational history, and mental health 34 http://bmjopen.bmj.com/ 35 173 via anxiety with regard to questions about radiation after the FNPS accident. 36 37 38 Anxiety () Anxiety (+) 39 Variable Unit pvalues 40 (n=269) (%) (n=161) (%) 41

42 Gender Women/ 262(97.4)/ 154(95.7)/ on September 24, 2021 by guest. Protected copyright. 0.32 43 Men 7(2.6) 7(4.3) 44 Age <40 years old/ 77(28.6)/ 87(54.0)/ 45 <0.001 46 ≥40 years old 192(71.4) 74(46.0) 47 Working experience as a public <10 years/ 53(19.7)/ 71(44.1)/ <0.001 48 health nurse ≥10 years 216(80.3) 90(55.9) 49 Activity area Hamadori/ 54(20.1)/ 29(18.0)/ 50 0.62 51 Other area 215(79.9) 132(72.0) 52 Position in the workplace Manager/ 88(32.7)/ 31(19.3)/ 0.003 53 Staff 181(67.3) 130(80.7) 54 Occupation at the time of the PHNs/ 55 230(85.5)/ 100(62.1)/ accident Others (nurses, <0.001 56 39(14.5) 61(37.9) 57 students) 58 59 10 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 11 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 Did you have children ≤15 6 years old at the time of the Yes 110(40.9) 59(36.6) 0.42 7 8 accident? 9 Education history in Yes 114(42.4) 80(49.7) 0.16 10 curriculum 11 Education history in seminar 12 Yes 25(9.3) 12(7.5) 0.60 13 before the accident 14 Education history in seminar Yes 247(91.8) 140(87.0) 0.13 15 after the accidentFor peer review only 16 Frequency of participation in Once/ 47(19.0)/ 42(29.6)/ 17 0.02 18 seminars Plural 200(81.0) 98(70.4) 19 SOC13 total points Mean 44.0 41.4 0.47 20 21 174 22 23 175 In the anxiety (+) group, the ratio of those having current anxiety about radiation 24 25 26 176 was significantly higher than that in the anxiety () group (p<0.001, Table 3). On the 27 28 177 other hand, in the anxiety () group, the ratios with difficulty answering the questions 29 30 178 about radiation, currently having the materials to obtain knowledge about radiation, and 31 32 33 179 having knowledge about childhood thyroid cancer increases after the Chernobyl 34 http://bmjopen.bmj.com/ 35 180 accident were significantly higher than in the anxiety (+) group (p<0.05, p<0.01, and 36 37 38 181 p<0.05, respectively, Table 3). However, there were no significant changes between the 39 40 182 two groups in the anxiety about radiation at the time of the accident and the recognition 41

42 on September 24, 2021 by guest. Protected copyright. 43 183 of health effects (such as late effects and genetic effects) due to radiation exposure 44 45 184 (p=0.68, p=0.79, and p=0.20, respectively, Table 3). 46 47 48 185 49 50 186 Table 3. Participants’ anxiety, recognition, and knowledge about radiation via 51 52 53 187 anxiety with regard to answering the questions about radiation after the FDNPS 54 55 188 accident. 56 57 58 59 11 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 12 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 Anxiety () Anxiety (+) 7 Question Unit pvalues 8 (n=269) (%) (n=161) (%) 9 10 Degree of anxiety about radiation at anxiety ()/ 99(36.8)/ 56(34.8)/ 11 0.68 the time of the FDNPS accident anxiety (+) 170(63.2) 105(65.2) 12 Degree of anxiety about radiation anxiety ()/ 251(93.3)/ 130(80.7)/ 13 <0.001 14 currently anxiety (+) 18(6.7) 31(19.3) 15 Do you thinkFor that delayed peer effects such review only 16 as malignancies occur due to radiation 17 Yes 37(13.8) 33(20.5) 0.79 18 exposure following the Fukushima 19 accident? 20 Do you think that genetic effects in 21 offspring occur due to radiation 22 Yes 33(12.3) 27(16.8) 0.20 23 exposure following the Fukushima 24 accident? 25 Did you have a difficult time 26 answering the questions about Yes 216(80.3) 115(71.4) 0.04 27 radiation? 28 29 Did you have the materials to obtain 30 knowledge about radiation at the time Yes 87(32.3) 40(24.8) 0.10 31 of the accident? 32 Do you currently have the materials to 33 Yes 233(86.6) 118(73.3) 0.01 34 obtain knowledge about radiation? http://bmjopen.bmj.com/ Did you know about the three 35 Yes 64(23.8) 42(26.1) 0.64 36 principles of radiation protection? 37 Did you know about the annual dose 38 Yes 20(12.4) 11(6.8) 0.99 39 limit for the general public? Did you know about the halflife of 40 Yes 129(48.0) 77(47.8) 0.99 41 radioactive substances? 42 Did you know about childhood on September 24, 2021 by guest. Protected copyright. 43 thyroid cancer increases after the Yes 213(79.2) 109(67.7) 0.01 44 45 Chernobyl accident? 46 47 189 48 49 190 When the logistic regression analysis was conducted, following the adjustment 50 51 191 for confounding factors, being a PHN at the time of the accident (OR: 2.37, p<0.01), 52 53 54 192 current general anxieties about radiation (OR: 3.56, p<0.001), currently having the 55 56 193 materials to obtain knowledge about radiation (OR: 2.11, p<0.01), and having 57 58 59 12 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 13 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 194 knowledge about childhood thyroid cancer increases after the Chernobyl accident (OR: 7 8 195 1.69, p=0.04) were all significantly associated with anxiety after the FDNPS accident 9 10 11 196 (Table 4). 12 13 197 14 15 For peer review only 16 198 Table 4. Odds ratios and 95% confidence intervals of the study variables for 17 18 199 anxiety (+) by asking them to answer questions about radiation, as assessed by the 19 20 21 200 logistic regression analysis. 22 95% confidence 23 Variable Unit Odds ratio pvalue 24 interval 25 Adjusted 26 Age ≥40 years old 0.64 0.361.15 0.13 27 Manager in the 28 No 1.14 0.652.00 0.66 29 workplace 30 Public health nurse at No 2.37 1.274.42 0.007 31 the time of the accident 32 Current degree of 33 anxiety (+) 3.56 1.826.96 <0.001 34 anxiety about radiation http://bmjopen.bmj.com/ 35 Difficulty answering 36 radiation questions in No 1.27 0.762.12 0.37 37 the past 38 39 Currently have materials to obtain 40 No 2.11 1.253.60 0.006 41 knowledge about 42 radiation on September 24, 2021 by guest. Protected copyright. 43 Knowledge about 44 childhood thyroid 45 No 1.69 1.042.75 0.04 46 cancer increase after the 47 Chernobyl accident 48 Unadjusted 49 50 Age ≥40 years old 0.34 0.230.51 <0.001 51 Manager in the No 2.04 1.283.25 0.003 52 workplace 53 Public health nurse at 54 No 3.60 2.265.73 <0.001 55 the time of the accident 56 Current degree of anxiety (+) 3.33 1.796.17 <0.001 57 58 59 13 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 14 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 anxiety about radiation 6 7 Difficulty answering 8 radiation questions in No 1.63 1.032.57 0.04 9 the past 10 Currently have 11 materials to obtain 12 No 2.36 1.443.87 <0.001 13 knowledge about 14 radiation 15 KnowledgeFor about peer review only 16 childhood thyroid 17 No 1.82 1.172.82 0.008 18 cancer increase after the 19 Chernobyl accident 20 201 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

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1 2 3 4 5 202 Discussion 6 7 203 This study was conducted four years after the FDNPS disaster to provide 8 9 10 204 educational support for PHNs who receive many consultations from residents. In 11 12 205 univariate analysis, younger and inexperienced PHNs had higher anxiety with regard to 13 14 206 communicating with residents about radiation. When adjusting for other variables, those 15 For peer review only 16 17 207 PHNs who were students at the time of the accident had higher anxiety when 18 19 208 communicating with residents about radiation. Our results suggested that experience as 20 21 22 209 a professional during the FDNPS accident is important. Although many of the PHNs 23 24 210 had knowledge about the Chernobyl accident, they could not properly communicate the 25 26 27 211 health effects of radiation with the residents, which caused anxiety in the residents after 28 29 212 the accident at the FDNPS. In addition, our results showed that having the materials to 30 31 32 213 obtain knowledge about radiation was independently associated with anxiety about the 33 34 214 FDNPS accident. http://bmjopen.bmj.com/ 35 36 37 215 These results suggest that continuous effort is necessary to provided education 38 39 216 and materials among the PHNs in the Fukushima Prefecture for them to gain knowledge 40 41 217 about radiation, including the health effects caused by radiation exposure [17]. Some 42 on September 24, 2021 by guest. Protected copyright. 43 44 218 education initiatives have been undertaken in the prefecture after the nuclear accident, 45 46 219 which includes Fukushima Medical University’s disaster education for undergraduates 47 48 49 220 and health literacy training for public health nurses for field practitioners [18, 19]. 50 51 221 Appropriate and sustainable allocation of financial and human resources is needed to 52 53 54 222 continue and expand such activities. 55 56 223 The SOC was employed to estimate the stress management capability of the 57 58 59 15 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 16 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 224 PHNs in this study. There was no significant difference in the mean points in the SOC 7 8 225 observed between the anxiety () group and anxiety (+) group. This result, as well as 9 10 11 226 other study, may suggest that factor of lifestyle related [20]. On the other hand, Eriksson 12 13 227 et al. showed that individuals with high scores in the SOC are better able to cope with 14 15 For peer review only 16 228 chronic stress than those with low scores [21]. In other studies, the average points of the 17 18 229 nurse at two Japanese hospitals were 38.5±6.4 and 39.3±6.3, respectively [22, 23], and 19 20 21 230 the average score of mothers of children with intellectual disabilities in Japan was 22 23 231 40.0±8.0 [24]. In this study, the average score (43.0±7.7) was higher than those in other 24 25 232 26 studies, and it was substantially higher when compared to those of nurses. We believe 27 28 233 that expertise as a public health nurse is one of the factors that increase the SOC. 29 30 234 Accordingly, in order to maintain the high scores of in the SOC, there is a need for 31 32 33 235 planning of stress management capacity improvement for the PHNs in Fukushima 34 http://bmjopen.bmj.com/ 35 236 Prefecture. 36 37 38 237 The correspondence of the disaster affected the stress management capability, and 39 40 238 might cause a worsening of chronic stress. According to the FHMS, which includes 41

42 on September 24, 2021 by guest. Protected copyright. 43 239 monitoring the mental health and daily lives of Fukushima residents and providing 44 45 240 proper care for them, the mental health status of the residents in the Fukushima 46 47 48 241 Prefecture was very poor [13]. Thus, the mental health of the residents was greatly 49 50 242 affected by the disaster, and a similar impact could be expected from the PHNs who 51 52 53 243 work in the Fukushima Prefecture. Therefore, mental support is important for the PHNs, 54 55 244 as well as for the residents of the Fukushima Prefecture. 56 57 58 59 16 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 17 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 245 The present study has several limitations. First, we could not obtain sufficient 7 8 246 information on the anxietyrelated factors, such as detailed consultation contents and 9 10 11 247 other information. Second, we were not able to gather sufficient information on stress 12 13 248 management factors, such as family issues and marital status. Third, this study might 14 15 For peer review only 16 249 have caused a recall bias on the study participants. Finally, since this study targeted to 17 18 250 PHNs only in Fukushima, Japan, there might be a problem about generalizability. 19 20 21 251 However, we believe that this study regarding the PHNs’ situation in the Fukushima 22 23 252 Prefecture four years after the FDNPS disaster will be very important in the provision of 24 25 253 26 future support. 27 28 254 In conclusion, we conducted a survey of the radiation anxiety and stress 29 30 255 processing capacity of PHNs in the Fukushima Prefecture four years after the nuclear 31 32 33 256 accident at the FDNPS, and determined that it is important for PHNs to obtain 34 http://bmjopen.bmj.com/ 35 257 knowledge and teaching materials about radiation. In order to develop workers’ 36 37 38 258 capabilities that can correspond to the timing of radiation disasters in the future, 39 40 259 radiation education programs for PHNs and nursing students must be established in 41

42 on September 24, 2021 by guest. Protected copyright. 43 260 areas that have nuclear power stations and other nuclear facilities. 44 45 261 46 47 48 262 Footnotes 49 50 263 Contributorship statement 51 52 ・ 53 264 Koji Yoshida conceived and designed the experiments, analyzed the data, wrote the 54 55 265 paper, prepared Tables. 56 57 58 59 17 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 18 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 266 ・Makiko Orita, Akira Ohtsuru, Aya Goto, Atsushi Kumagai and Kiyotaka Yasui 7 8 267 contributed materials, reviewed drafts of the paper. 9 10 11 268 ・Naomi Hayashida, Takashi Kudo, and Shunichi Yamashita designed the experiments, 12 13 269 reviewed drafts of the paper. 14 15 For peer review only 16 270 • Noboru Takamura conceived and designed the experiments, wrote the paper, 17 18 271 reviewed drafts of the paper. 19 20 21 272 22 23 273 Competing interests 24 25 274 26 There are no competing interests 27 28 275 29 30 276 Funding 31 32 33 277 This study was partly supported by Japan Society for Promotion of Science. 34 http://bmjopen.bmj.com/ 35 278 36 37 38 279 Data sharing statement 39 40 280 No additional data are available. 41

42 281 on September 24, 2021 by guest. Protected copyright. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 18 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 19 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 282 6 283 7 References 8 284 1. United Nations Scientific Committee on the Effects of Atomic Radiation. 9 10 11 285 UNSCEAR 2013 Report Volume I Report to the general assembly scientific 12 13 286 annex A: Levels and effects of radiation exposure due to the nuclear accident 14 15 For peer review only 16 287 after the 2011 Great eastJapan earthquake and tsunami. Available: 17 18 288 http://www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf 19 20 21 289 (accessed 16 July 2016). 22 23 290 2. International Atomic Energy Agency. The Fukushima Daiichi accident Technical 24 25 291 26 Volume 4. Radiological Consequences. Vienna: International Atomic Energy 27 28 292 Agency (IAEA). 2015: 1250. 29 30 293 3. Nuclear Emergency Response Headquarters of Japanese Government. Report of 31 32 33 294 Japanese government to the IAEA ministerial conference on nuclear safety. The 34 http://bmjopen.bmj.com/ 35 295 Accident at TEPCO’s Fukushima nuclear power stations. Available: 36 37 38 296 http://japan.kantei.go.jp/kan/topics/201106/iaea_houkokusho_e.html (accessed 39 40 297 16 July 2016). 41

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1 2 3 4 5 6 304 doses in residents living around the Fukushima Nuclear Power Plant. Rad Res. 7 8 305 2013;180: 439447. doi: 10.1667/RR13351.1 9 10 11 306 6. Nagataki S, Takamura N. A review of the Fukushima nuclear reactor accident: 12 13 307 radiation effects on the thyroid and strategies for prevention. Curr Opin 14 15 For peer review only 16 308 Endocrinol Diabetes Obes. 2014;21: 384393. doi: 17 18 309 10.1097/MED.0000000000000098 19 20 21 310 7. Ishikawa T, Yasumura S, Ozasa K, et al. The Fukushima Health Management 22 23 311 Survey: estimation of external doses to residents in Fukushima Prefecture. Sci 24 25 312 26 Rep. 2015;5: 12712. 111. doi: 10.1038/srep12712 27 28 313 8. Yoshida K, Hashiguchi K, Taira Y, et al. Importance of personal dose equivalent 29 30 314 evaluation in Fukushima in overcoming social panic. Radiat Prot Dosimetry. 31 32 33 315 2012;151(1): 1446. doi: 10.1093/rpd/ncr466 34 http://bmjopen.bmj.com/ 35 316 9. WHO (World Health Organization) 2005a. Health Effects of the Chernobyl 36 37 38 317 Accident and Special Health Care Programmes. Available: 39 40 318 http://www.who.int/ionizing_radiation/a_e/chernobyl/EGH%20Master%20file 41

42 on September 24, 2021 by guest. Protected copyright. 43 319 %202005.08.24.pdf. (accessed 16 July 2016). 44 45 320 10. WHO (World Health Organization) 2005b. Chernobyl: The true scale of the 46 47 48 321 accident; 20 Years Later a UN Report Provides Definitive Answers and Ways to 49 50 322 Repair Lives. Available: 51 52 53 323 http://www.who.int/mediacentre/news/releases/2005/pr38/en/ (accessed 16 July 54 55 324 2016). 56 57 58 59 20 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 21 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 325 11. WHO (World Health Organization). Health effects of the Chernobyl Accident 7 8 326 and Special Health Care Programmes. Geneva:WHO 2006. Available: 9 10 11 327 http://www.who.int/ionizing_radiation/chernobyl/who_chernobyl_report_2006.p 12 13 328 df#search=%2715.+WHO+%28World+Health+Organization%29.+Health+effect 14 15 For peer review only 16 329 s+of+the+Chernobyl+Accident+and+Special+Health+Car%27.pdf. (accessed 16 17 18 330 July 2016). 19 20 21 331 12. Yasumura S, Hosoya M, Yamashita S, et al. Study Protocol for the Fukushima 22 23 332 Health Management Survey. J Epidemiol. 2012;22: 375383. PMID: 22955043 24 25 333 26 13. Yabe H, Suzuki Y, Mashiko H, et al. Psychological distress after the Great East 27 28 334 Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident: results 29 30 335 of a mental health and lifestyle survey through the Fukushima Health 31 32 33 336 Management Survey in FY2011 and FY2012. Fukushima J Med Sci. 2014;60(1): 34 http://bmjopen.bmj.com/ 35 337 5767. PMID: 25030715 36 37 38 338 14. Ohira T, Hosoya M, Yasumura S, et al. Effect of Evacuation on Body Weight 39 40 339 After the Great East Japan Earthquake. Am J Prev Med. 2016;50(5): 55360. doi: 41

42 on September 24, 2021 by guest. Protected copyright. 43 340 10.1016/j.amepre.2015.10.008 44 45 341 15. Satoh H, Ohira T, Hosoya M, et al. Evacuation after the Fukushima Daiichi 46 47 48 342 Nuclear Power Plant Accident Is a Cause of Diabetes: Results from the 49 50 343 Fukushima Health Management Survey. J Diabetes Res. 2015: 627390. doi: 51 52 53 344 10.1155/2015/627390 54 55 345 16. Antonovsky A. The structure and properties of the sense of coherence scale. Soc 56 57 58 59 21 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Page 22 of 25 BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 346 Sci Med. 1993;36(6): 72533. PMID: 8480217 7 8 347 17. Konishi E, Nagai T, Kobayashi M, et al. PostFukushima radiation education for 9 10 11 348 public health nursing students: a case study. Int Nurs Rev. 2016;63(2): 2929. 12 13 349 doi: 10.1111/inr.12244 14 15 For peer review only 16 350 18. Ohtsuru A, Tanigawa K, Kumagai A, et al. Nuclear disasters and health: lessons 17 18 351 learned, challenges, and proposals. Lancet. 2015;386(9992): 489497. doi: 19 20 21 352 http://dx.doi.org/10.1016/S01406736(15)609941 22 23 353 19. Goto A, Lai AY, Rudd RE. Health literacy training for public health nurses in 24 25 354 26 Fukushima: A multisite program evaluation. Japan Med Assoc J. 2015;58(3): 27 28 355 6977. PMID: 26870621 29 30 356 20. Wainwright NW, Surtees PG, Welch AA, et al. Healthy lifestyle choices: could 31 32 33 357 sense of coherence aid health promotion? J Epidemiol Community Health. 34 http://bmjopen.bmj.com/ 35 358 2007;61(10): 8716. doi: 10.1136/jech.2006.056275 36 37 38 359 21. Eriksson M, Lindström B. Antonovsky's sense of coherence scale and the 39 40 360 relation with health: a systematic review. J Epidemiol Community Health. 41

42 on September 24, 2021 by guest. Protected copyright. 43 361 2006;60(5): 37681. doi: 10.1136/jech.2005.041616 44 45 362 22. Tanaka I, Higa H, Yamada K. Comparison of clinical nursing competence based 46 47 48 363 on attributes of nurses, and relationship between number of working years, sense 49 50 364 of coherence, and spirituality. The Toyama University journal of nursing. 51 52 53 365 2012;12(2): 8192. (in Japanese) 54 55 366 23. Kawabata M. Related factors to the spirituality and sense of coherence (SOC) of 56 57 58 59 22 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 23 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

1 2 3 4 5 6 367 nurses involved in the nursing of terminal stage cancer patients. Studies in 7 8 368 nursing and rehabilitation 2010;(5), 4149. (in Japanese) 9 10 11 369 24. Kimura M, Yamazaki Y. Mental health and positive change among Japanese 12 13 370 mothers of children with intellectual disabilities: Roles of sense of coherence 14 15 For peer review only 16 371 and social capital. Res Dev Disabil. 2016;59: 4354. doi: 17 18 372 10.1016/j.ridd.2016.07.009. 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

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7 abstract Pages 1 and 3-4 8 (b) Provide in the abstract an informative and balanced summary of what was done 9 and what was found Pages 3-4 10 Introduction 11 12 Background/rationale ✓2 Explain the scientific background and rationale for the investigation being reported 13 Pages 5-6 14 Objectives ✓3 State specific objectives, including any prespecified hypotheses Page 6 15 For peer review only 16 Methods 17 Study design ✓4 Present key elements of study design early in the paper Page 6 18 Setting ✓5 Describe the setting, locations, and relevant dates, including periods of recruitment, 19 exposure, follow-up, and data collection Page 6 20 21 Participants ✓6 (a) Give the eligibility criteria, and the sources and methods of selection of 22 participants Page 6 23 Variables ✓7 Clearly define all outcomes, exposures, predictors, potential confounders, and effect 24 modifiers. Give diagnostic criteria, if applicable Pages 7-8 25

26 Data sources/ ✓8* For each variable of interest, give sources of data and details of methods of 27 measurement assessment (measurement). Describe comparability of assessment methods if there 28 is more than one group Pages 6-7 29 Bias ✓9 Describe any efforts to address potential sources of bias Page 17 30 ✓ 31 Study size 10 Explain how the study size was arrived at Page 6 32 Quantitative variables ✓11 Explain how quantitative variables were handled in the analyses. If applicable, 33 describe which groupings were chosen and why Pages 7-8 http://bmjopen.bmj.com/ 34 Statistical methods ✓12 (a) Describe all statistical methods, including those used to control for confounding 35 Pages 7-8 b 36 ( ) Describe any methods used to examine subgroups and interactions 37 (c) Explain how missing data were addressed 38 (d) If applicable, describe analytical methods taking account of sampling strategy 39 (e) Describe any sensitivity analyses 40 41 Results

42 Participants ✓13* (a) Report numbers of individuals at each stage of study—eg numbers potentially on September 24, 2021 by guest. Protected copyright. 43 Pages 6 and 9 eligible, examined for eligibility, confirmed eligible, included in the study, 44 completing follow-up, and analysed 45 46 (b) Give reasons for non-participation at each stage 47 (c) Consider use of a flow diagram 48 Descriptive data ✓14* (a) Give characteristics of study participants (eg demographic, clinical, social) and 49 Pages 6 and 9 information on exposures and potential confounders 50 51 (b) Indicate number of participants with missing data for each variable of interest 52 Outcome data ✓15* Report numbers of outcome events or summary measures Pages 9-14 53 Main results ✓16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and 54 Table 4 their precision (eg, 95% confidence interval). Make clear which confounders were 55 56 adjusted for and why they were included 57 (b) Report category boundaries when continuous variables were categorized 58 (c) If relevant, consider translating estimates of relative risk into absolute risk for a 59 meaningful time period 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml1 Page 25 of 25 BMJ Open BMJ Open: first published as 10.1136/bmjopen-2016-013564 on 24 October 2016. Downloaded from

19 20 *Give information separately for exposed and unexposed groups. 21 22 Note: An Explanation and Elaboration article discusses each checklist item and gives methodological background and 23 published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely 24 available on the Web sites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at 25 26 http://www.annals.org/, and Epidemiology at http://www.epidem.com/). Information on the STROBE Initiative is 27 available at www.strobe-statement.org. 28 29 30 31 32 33 34 http://bmjopen.bmj.com/ 35 36 37 38 39 40 41

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