Design of the Health Examination Survey on Early Childhood Physical Growth in the Great East Japan Earthquake Affected Areas

Journal of Epidemiology 27 (2017) 135e142

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Journal of Epidemiology

journal homepage: http://www.journals.elsevier.com/journal-of-epidemiology/

Study Proﬁle Design of the health examination survey on early childhood physical growth in the Great East Japan Earthquake affected areas

Hiroko Matsubara a, Mami Ishikuro b, c, Masahiro Kikuya b, c, Shoichi Chida d, Mitsuaki Hosoya e, Atsushi Ono e, Noriko Kato f, Susumu Yokoya g, Toshiaki Tanaka h, * Tsuyoshi Isojima i, Zentaro Yamagata j, Soichiro Tanaka k, Shinichi Kuriyama a, b, c, , Shigeo Kure b, k a Department of Disaster Public Health, International Research Institute of Disaster Science (IRIDeS), Tohoku University, Sendai, Japan b Tohoku Medical Megabank Organization (ToMMo), Tohoku University, Sendai, Japan c Department of Molecular Epidemiology, Graduate School of Medicine, Tohoku University, Sendai, Japan d Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Japan e Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan f Department of Early Childhood and Elementary Education, Jumonji University, Niiza, Saitama, Japan g Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo, Japan h Japanese Association for Human Auxology, Tokyo, Japan i Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan j Department of Health Sciences, Graduate School Department of Interdisciplinary Research, University of Yamanashi, Chuo, Yamanashi, Japan k Department of Pediatrics, Graduate School of Medicine, Tohoku University, Sendai, Japan article info abstract

Article history: Background: To investigate the impact of the Great East Japan Earthquake on preschool children's Received 8 September 2015 physical growth in the disaster-affected areas, the three medical universities in Iwate, Miyagi, and Accepted 28 March 2016 Fukushima Prefectures conducted a health examination survey on early childhood physical growth. Available online 5 January 2017 Methods: The survey was conducted over a 3-year period to acquire data on children who were born in different years. Our targets were as follows: 1) children who were born between March 1, 2007 and Keywords: August 31, 2007 and experienced the disaster at 43e48 months of age, 2) children who were born be- The Great East Japan Earthquake tween March 1, 2009 and August 31, 2009 and experienced the disaster at 19e24 months of age, and 3) Preschool children Physical growth children who were born between June 1, 2010 and April 30, 2011 and were under 10 months of age or not Health examination born yet when the disaster occurred. We collected their health examination data from local governments Retrospective cohort study in Iwate, Miyagi, and Fukushima Prefectures. We also collected data from Aomori, Akita, and Yamagata Prefectures to use as a control group. The survey items included birth information, anthropometric measurements, and methods of nutrition during infancy. Results: Eighty municipalities from Iwate, Miyagi, and Fukushima Prefectures and 21 from the control prefectures participated in the survey. As a result, we established three retrospective cohorts consisting of 13,886, 15,474, and 32,202 preschool children. Conclusions: The large datasets acquired for the present survey will provide valuable epidemiological evidence that should shed light on preschool children's physical growth in relation to the disaster. © 2016 The Authors. Publishing services by Elsevier B.V. on behalf of The Japan Epidemiological Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

1. Introduction

The Paciﬁc coastal areas of Iwate, Miyagi, and Fukushima Pre- fectures were substantially damaged as a result of the Great East * Corresponding author. Department of Disaster Public Health, International Japan Earthquake on March 11, 2011. The damage to human life and Research Institute of Disaster Science (IRIDeS), Tohoku University, 2-1, property from the massive 9.0 magnitude earthquake and subse- Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan. quent giant tsunami were unprecedented in modern Japanese e E-mail address: [email protected] (S. Kuriyama). history.1 4 While there is great concern regarding the possible Peer review under responsibility of the Japan Epidemiological Association. http://dx.doi.org/10.1016/j.je.2016.03.001 0917-5040/© 2016 The Authors. Publishing services by Elsevier B.V. on behalf of The Japan Epidemiological Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 136 H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142 health impact among people who experienced the disaster, there is undergo the 3-year-old health examinations based on the maternal limited knowledge about how the occurrence of an enormous and child health handbooks14 (for the survey in Sendai City only). natural disaster in a developed country affects people's health.5,6 In Previous studies have reported that children in the northeast particular, we are concerned about the health of preschool children (Tohoku) region were more likely to be overweight than those in e who experienced the catastrophe during the most vulnerable other areas in Japan.15 18 Considering regional variations in physical e period of their physical and mental development.7 9 Several fac- growth, we selected preschool children residing in the other three tors, such as environmental changes to child care and post-disaster prefectures within the Tohoku region as a control group. Tohoku traumatic stress, might affect their health.10,11 University sent invitation letters to all 100 municipal governments One year after the disaster, the Department of Pediatrics at the in Aomori, Akita, and Yamagata Prefectures. If they agreed to three medical universities in Iwate, Miyagi, and Fukushima Pre- participate in the survey, persons in charge of maternal and child fectures collaboratively initiated two surveys: the nationwide health in the municipalities returned completed survey sheets. nursery school survey on child health throughout the Great East The survey was conducted over the 3-year period from July 2012 Japan Earthquake-affected areas12 and the present health exami- to October 2014. We decided the timeframe for birth of our targeted nation survey on early childhood physical growth in the Great East children backward from when they experienced the disaster after Japan Earthquake-affected areas. Using data from these surveys, we undergoing certain health examinations. During the ﬁrst year, we aim to provide comprehensive epidemiological evidence of the collected data on children who were born between March 1, 2007 impact of the disaster on preschool children's health. and August 31, 2007 (Cohort 1). These children experienced the In our nationwide survey, we targeted nursery school children disaster within 6 months after undergoing their 3-year-old health who experienced the disaster during their preschool days and examinations. During the second year, we collected data on chil- compared them to children who did not experience the disaster dren who were born between March 1, 2009 and August 31, 2009 using data collected from all 47 prefectures in Japan. In addition to (Cohort 2). These children experienced the disaster within 6 longitudinal data on physical measurements, we obtained data on months after undergoing their 1-and-a-half-year-old examina- the presence of diseases, history of moving in and moving out, and tions. Finally, during the third year, we collected data on children personal experience with the disaster. who were born between June 1, 2010 and April 30, 2011 (Cohort 3). In the present survey, we intend to validate the results of the These children experienced the disaster within 6 months after former survey. Furthermore, the present survey will allow us to undergoing their 3-month-old health examinations or after birth, examine how physical growth differs depending on the age at the or who were not born yet when the disaster occurred (Fig. 1). The time of experiencing the disaster among preschool children in the survey in Sendai City was conducted from April 2014 to December most affected areas. The present survey also includes information 2014. We collected data on children who underwent their 3-year- that was not examined in the former survey, including gestational old health examinations during the survey period. These children age of newborns, methods of nutrition during infancy, and head were born between September 2010 and May 2011. circumference. Here, we describe the design of the present survey and the results of data collection. 2.2. Survey items and measurements

The survey items included sex, birth information (date of birth, 2. Methods gestational age in the newborn, and supine length and weight at birth) and anthropometric measurements (length/height and 2.1. Survey design and population weight) taken at the following four time points: 1) during the early infantile period, when children were 3e4 months of age; 2) during We accessed 3-year-old health examination records, which the late infantile period, when children were between 6 and 10 allowed us to retrospectively acquire children's anthropometric months of age; 3) at the 1-and-a-half-year-old examination; and 4) at measurements during early childhood. In accordance with the the 3-year-old health examination. Additionally, we obtained infor- Maternal and Child Health Act in Japan,13 regular health examina- mation on their methods of nutrition (breast milk, artificial milk, or tions during early childhood are provided at least two times at the mixed milk) and head circumference during infancy (Table 1). municipal level: 1) over the age of 18 months and below the age of 2 years (referred to as the 1-and-a-half-year-old health examination) 2.3. Ethical consideration and 2) over the age of 3 years and below the age of 4 years (referred to as the 3-year-old health examination). The timing of regular The survey protocol was approved by the institutional review health examinations, including additional health examinations boards of Iwate Medical University, Tohoku University, and during infancy, varies by municipality. Fukushima Medical University. The present survey was conducted We invited all 127 municipal governments in Iwate, Miyagi, and in accordance with the national Ethical Guidelines for Epidemio- Fukushima Prefectures, which were most affected by the disaster, logical Research.19 We did not obtain informed consent from par- to participate in the survey. Iwate Medical University, Tohoku ticipants. We have publicly disclosed the information of the survey, University, and Fukushima Medical University sent a letter of including the significance, objectives, and methods on the Tohoku invitation, including an overview of the survey and a sample of the University School of Medicine website (http://www.med.tohoku.ac. survey sheet to the municipal governments in each prefecture. If jp/public/ekigaku2013.html). the municipal governments agreed to participate in the survey, they provided data by one of the following methods: 1) completion 3. Results of survey sheets by a person in charge of maternal and child health (usually, a public health nurse in the municipality); 2) a visit to the In total, 80 out of 127 municipalities from Iwate, Miyagi, and municipal government office to transcribe data (i.e., manual data Fukushima Prefectures participated in the survey as follows: 30 out collection); 3) submission of de-identified electronic datasets after of 33 municipalities in Iwate Prefecture (90.9%); 19 out of 35 mu- information that might identify individuals, such as name and nicipalities in Miyagi Prefecture (54.3%); and 31 out of 59 munici- address, was removed from pre-existing files; or 4) completion of palities in Fukushima Prefecture (52.5%). Regarding the control questionnaires by the parents of children who are scheduled to group, 21 out of 100 municipalities participated in the survey as H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142 137

Fig. 1. Survey timeline: timeframe for birth and body measurements. Each cohort was retrospectively followed up at four different time points to determine changes in length/ height and weight over time. Information on methods of nutrition and head circumference was collected during the ﬁrst and the second measurements. The exact timeframe for the 1-and-a-half-year-old and the 3-year-old health examinations varies by municipalities.

Table 1 Comparison of two surveys.

Health examination survey on early childhood physical growth Nationwide nursery school survey on child health12 (present survey)

Data source 80 municiparities in Iwate, Miyagi, and Fukushima Prefectures 3624 nursery schools in 47 prefectures As a control group, 21 municiparities in Aomori, Akita, and Yamagata Prefectures

Target (Sample size) 1) Children who were born between March 1, 2007 and August 1) Children who were born between April 2, 2004 and April 1, 31, 2007 (n ¼ 13,886) 2005 (n ¼ 53,747) 2) Children who were born between March 1, 2009 and August 2) Children who were born between April 2, 2006 and April 1, 31, 2009 (n ¼ 15,474) 2007 (n ¼ 69,004) 3)Children who were born between June 1, 2010 and April 30, 2011 and those who were born between September 1, 2010 and May 31, 2011 in Sendai City (n ¼ 32,202)

Survey Items Sex Sex Date of birth Month of birth Birth information (gestational age of the newborn, supine N/A length, and weight) Methods of nutrition during infancy N/A N/A Presence of disease N/A Change of residence N/A Personal experience with the disastera

Anthropometric measurements Length/height and weight until the age of 4 years (up to 5 times) Length/height and weight until the age of 7 years (up to 14 times) Head circumference during infancy (up to 2 times) N/A

a For children who were born between April 2, 2006 and April 1, 2007. follows: 7 out of 40 municipalities in Aomori Prefecture (17.5%); 8 Ultimately, we established three retrospective cohorts of pre- out of 25 municipalities in Akita Prefecture (32.0%); and 6 out of 35 school children. Cohort 1 comprised 13,886 children who were municipalities in Yamagata Prefecture (17.1%) (Fig. 2). Among 79 born between March 2007 and August 2007 and Cohort 2 municipalities in the affected prefectures, with the exception of comprised 15,474 children who were born between March 2009 Sendai City, 27 municipalities returned completed survey sheets, and and August 2009. Cohort 3 comprised 32,202 children: 25,909 two municipalities submitted de-identiﬁed electronic datasets. We children who were born between June 2010 and February 2011 visited 50 municipalities to transcribe data (Table 2 and eTable 1). (Cohort 3-1) and 6293 children who were born between March With continued cooperation from local governments, we ob- 2011 and May 2011 (Cohort 3-2). We deﬁned these children in tained data on 15,406 preschool children for Cohort 1, 15,541 Cohorts 3-1 and 3-2 as children who were born before the disaster children for Cohort 2, and 27,422 children for Cohort 3. Addi- and children who were born after the disaster, respectively. Because tionally, we collected 5288 questionnaires from Sendai City for seven municipalities did not provide children's date of birth Cohort 3. We excluded children whose sex, birth month, or (constituting 35.8% of children who were born in March 2011), we anthropometric measurements were missing (68 children from were unable to divide Cohort 3 into children who were born before Cohort 1, 66 from Cohort 2, and 451 from Cohort 3) and who were March 11, 2011 and children who were born after March 11, 2011. born in months outside of our target period (1,452, 1, and 57 The background characteristics of children by cohort are presented children, respectively). in Table 3. 138 H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142

Fig. 2. Geographical location of the municipalities participated in the survey. In total, 80 out of 127 municipalities in Iwate, Miyagi, and Fukushima Prefectures that were severely affected by the disaster and 21 out of 100 municipalities in Aomori, Akita, and Yamagata Prefectures participated in the survey. Additionally, the data of Satsumasendai City in Kagoshima Prefecture, a municipality other than the Tohoku region was available.

Table 2 4. Discussion Number of municipalilies that participated in the survey and choice of data collection method. Children are one of the most vulnerable populations to the ef- Number of Choice of data 20e23 municipalities collection methoda fects of natural disasters, yet little is known about how tragic and devastating disasters affect their health. We conducted the As of July 2012 Participation 1 2 3 4 present survey to address specific concerns regarding the impact of Affected prefectures the Great East Japan Earthquake on the physical growth of pre- Iwate 33 30 90.9% 11 17 2 0 school children in the most severely affected areas. Miyagi 35 19 54.3% 9 9 0 1 Fukushima 59 31 52.5% 7 24 0 0 The strength of the present survey is the establishment of three Total 127 80 63.0% 27 50 2 1 retrospective cohorts of preschool children who were born in different years, which enable us to evaluate differences in physical Control prefectures growth among preschool children of varying ages at the time of the Aomori 40 7 17.5% 7 0 0 0 disaster. For example, comparison analyses using growth data from Akita 25 8 32.0% 8 0 0 0 Cohort 1 and Cohort 2 can serve to clarify differences in physical Yamagata 35 6 17.1% 4 2 0 0 Total 100 21 21.0% 19 2 0 0 growth between children who experienced the disaster before and after 3 years of age. A part of the growth data from Cohort 3 might a Method 1: completion of survey sheets by a person of the municipality. Method 2: a visit to the municipal government office to transcribe data. provide information about children who experienced the disaster Method 3: submission of de-identified electronic datasets. during their prenatal period. Method 4: completion of questionnaires by parents (Sendai City only). A total of 80 municipalities in the most affected prefectures of Iwate, Miyagi, and Fukushima participated in the survey. With the Additionally, we obtained data from Satsumasendai City in exception of Sendai City (for Cohort 3), the number of children who Kagoshima Prefecture, a municipality outside of the Tohoku region participated in Cohort 1, 2, and 3 was equivalent to 50%, 60%, and (Fig. 2 and eTable 2). 63%, respectively, of the total number of births in the three H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142 139

Table 3a Table 3c Background characteristics of Cohort 1. Children who were born between March 1, Background characteristics of Cohort 3-1. Children who were born between June 1, 2007 and August 31, 2007 (n ¼ 13,886). 2010 and February 28, 2011 (n ¼ 25,909).

Affected prefecturesa Control prefecturesb All Japanc Affected prefecturesa Control prefecturesb All Japanc (in 2007) (in 2010)

n%n%n% n%n%n%

Sex Sex Boy 6137 51.3% 985 51.1% 559,847 51.4% Boy 11,851 51.3% 1465 51.8% 550,742 51.4% Girl 5823 48.7% 941 48.9% 529,971 48.6% Girl 11,229 48.7% 1364 48.2% 520,562 48.6% Total 11,960 100.0% 1926 100.0% 1,089,818 100.0% Total 23,080 100.0% 2829 100.0% 1,071,304 100.0%

Birthweight, g Birthweight, g <1000 18 0.2% 3 0.2% 3414 0.3% <1000 44 0.2% 6 0.2% 3232 0.3% 1000e1499 47 0.4% 13 0.7% 5111 0.5% 1000e1499 87 0.4% 13 0.5% 4854 0.5% 1500e1999 127 1.1% 21 1.1% 13,578 1.2% 1500e1999 240 1.0% 38 1.3% 12,994 1.2% 2000e2499 789 6.6% 133 6.9% 83,061 7.6% 2000e2499 1612 7.0% 176 6.2% 81,969 7.7% 2500e2999 4224 35.3% 608 31.6% 416,241 38.2% 2500e2999 8423 36.5% 796 28.1% 415,293 38.8% 3000e3499 4614 38.6% 750 38.9% 448,576 41.2% 3000e3499 9022 39.1% 950 33.6% 439,329 41.0% 3,500e3,999 1161 9.7% 174 9.0% 109,918 10.1% 3500e3999 2232 9.7% 240 8.5% 104,680 9.8% 4000 109 0.9% 15 0.8% 9722 0.9% 4000 165 0.7% 21 0.7% 8713 0.8% Missing 871 7.3% 209 10.9% 197 0.0% Missing 1255 5.4% 589 20.8% 240 0.0% Total 11,960 100.0% 1926 100.0% 1,089,818 100.0% Total 23,080 100.0% 2829 100.0% 1,071,304 100.0%

Gestational age of the newborn, weeks Gestational age of the newborn, weeks <28 18 0.2% 2 0.1% 2869 0.3% <28 36 0.2% 5 0.2% 2782 0.3% 28e31 50 0.4% 19 1.0% 5281 0.5% 28e31 96 0.4% 12 0.4% 5025 0.5% 32e35 233 1.9% 33 1.7% 23,545 2.2% 32e35 440 1.9% 60 2.1% 22,735 2.1% 36e39 6064 50.7% 890 46.2% 659,170 60.5% 36e39 11,930 51.7% 1242 43.9% 662,432 61.8% 40 4096 34.2% 573 29.8% 398,567 36.6% 40 8011 34.7% 776 27.4% 377,956 35.3% Missing 1499 12.5% 409 21.2% 386 0.0% Missing 2567 11.1% 734 25.9% 374 0.0% Total 11,960 100.0% 1926 100.0% 1,089,818 100.0% Total 23,080 100.0% 2829 100.0% 1,071,304 100.0%

Table 3b Table 3d Background characteristics of Cohort 2. Children who were born between March 1, Background characteristics of Cohort 3-2. Children who were born between March 2009 and August 31, 2009 (n ¼ 15,474). 1, 2011 and May 31, 2011 (n ¼ 6293).

Affected prefecturesa Control prefecturesb All Japanc Affected prefecturesa Control prefecturesb All Japanc (in 2009) (in 2011)

n%n%n% n%n%n%

Sex Sex Boy 6891 51.3% 962 50.1% 548,993 51.3% Boy 2850 49.6% 267 48.5% 538,271 51.4% Girl 6663 48.7% 958 49.9% 521,042 48.7% Girl 2892 50.4% 284 51.5% 512,535 48.6% Total 13,554 100.0% 1920 100.0% 1,070,035 100.0% Total 5742 100.0% 551 100.0% 1,050,806 100.0%

Birthweight, g Birthweight, g <1000 21 0.2% 2 0.1% 3150 0.3% <1000 8 0.1% 2 0.4% 3120 0.3% 1000e1499 68 0.5% 5 0.3% 4853 0.5% 1000e1499 21 0.4% 5 0.9% 4822 0.5% 1500e1999 152 1.1% 16 0.8% 12,985 1.2% 1500e1999 55 1.0% 9 1.6% 12,614 1.2% 2000e2499 867 6.4% 97 5.1% 81,683 7.6% 2000e2499 422 7.3% 46 8.3% 79,822 7.6% 2500e2999 4791 35.3% 586 30.5% 413,013 38.6% 2500e2999 2080 36.2% 163 29.6% 405,714 38.6% 3000e3499 5113 37.7% 713 37.1% 439,503 41.1% 3,000e3,499 2288 39.8% 184 33.4% 431,711 41.1% 3,500e3,999 1254 9.3% 184 9.6% 105,670 9.9% 3500e3999 583 10.2% 60 10.9% 104,195 9.9% 4000 111 0.8% 15 0.8% 8955 0.8% 4000 46 0.8% 3 0.5% 8578 0.8% Missing 1177 8.7% 302 15.7% 223 0.0% Missing 239 4.2% 79 14.3% 230 0.0% Total 13,554 100.0% 1920 100.0% 1,070,035 100.0% Total 5742 100.0% 551 100.0% 1,050,806 100.0%

Gestational age of the newborn, weeks Gestational age of the newborn (weeks) <28 22 0.2% 3 0.2% 2717 0.3% <28 5 0.1% 2 0.4% 2667 0.3% 28e31 57 0.4% 3 0.2% 4875 0.5% 28e31 25 0.4% 6 1.1% 5101 0.5% 32e35 245 1.8% 24 1.3% 22,506 2.1% 32e35 87 1.5% 12 2.2% 22,269 2.1% 36e39 6930 51.1% 898 46.8% 654,573 61.2% 36e39 3137 54.6% 251 45.6% 652,182 61.8% 40 4433 32.7% 642 33.4% 384,940 36.0% 40 1977 34.4% 183 33.2% 3,68,212 35.3% Missing 1867 13.8% 350 18.2% 424 0.0% Missing 511 8.9% 97 17.6% 375 0.0% Total 13,554 100.0% 1920 100.0% 1,070,035 100.0% Total 5742 100.0% 551 100.0% 1,050,806 100.0%

a Affected prefectures include Iwate, Miyagi, and Fukushima Prefectures. a Affected prefectures include Iwate, Miyagi, and Fukushima Prefectures. b Control prefectures include Aomori, Akita, and Yamagata Prefectures. b Control prefectures include Aomori, Akita, and Yamagata Prefectures. c Source: Vital Statistics in Japan Annual Report 2009, Statistics and Information c Source: Vital Statistics in Japan Annual Report 2007, Statistics and Information Department, MHLW. Department, Ministry of Health, Labour and Welfare (MHLW). 140 H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142 prefectures during the same period (11,960 out of a population of although we invited all 100 municipalities in Aomori, Akita, and 23,818 for Cohort 1, 13,554 out of a population of 22,634 for Cohort Yamagata Prefectures, only 21 municipalities (21%) agreed to e 2, and 23,611 out of a population of 37,554 for Cohort 3).24 26 participate in the survey. This low participation of the control Although we were unable to obtain data from Sendai City for the prefectures may have resulted in selection bias due to a non- first 2 years, the number of children who participated in Cohort 3 representative unexposed group. However, we obtained data from comprised 75.7% of the births in the city during the corresponding a variety of municipalities in terms of geographical location, pop- period. Thus, we acquired one of the largest datasets of Japanese ulation size, and birth rate (Fig. 2 and Table 4). We assume that any preschool children to date, which should guarantee sufficient realized bias would be relatively small. Third, for the convenience of regional representativeness. participating municipalities, we used four methods to collect data. Body measurements at regular health examinations have been Data collected using varying procedures may have resulted in performed by trained public health nurses in each municipality different quality or accuracy of information between municipalities. who are required to follow appropriate procedures recommended However, our obtained data may be less likely to have flaws and by the Ministry of Health, Labour and Welfare.27 For the survey in errors than other types of data collected using varying procedures Sendai City, we asked parents to complete the questionnaires based because certified public health nurses in each municipality sub- on their maternal and child health handbooks, in which obstetri- mitted preexisting datasets or completed survey sheets. As cians, pediatricians, and health nurses have written children's mentioned previously, parents completed the questionnaires based health records, including body measurements, immunizations, and on their maternal and child health handbooks, which are generally illnesses.14 Therefore, the obtained measurement data are consid- recorded by health professionals. Also, experienced and expert ered sufficiently reliable and accurate. persons performed data transcription and entry. Fourth, we could On the other hand, the present survey did have several limita- not obtain important birth information, such as fetal number, birth tions. First, as we anticipated, we were unable to obtain data from order, age of mother, way of delivery, and abnormalities present at the Pacific coastal municipalities, including Otsuchi (in Iwate Pre- birth. We accessed 3-year-old health examination records and ac- fecture) and Minamisanriku, and Onagawa (both in Miyagi Prefec- quired children's anthropometric measurements during early ture), because their town offices were completely destroyed by the childhood. Because the forms used for maintaining individuals' tsunami and health records were no longer available. Additionally, health information were not standardized and included items var- we were unable to contact certain towns in the eastern part ied by municipality, such information was not available for all (referred to as Hamadouri) of Fukushima Prefecture that are located municipalities. However, we did obtain some birth information that within the evacuation zone within 20 km of the Fukushima Daiichi may influence children's physical growth and can be used to assess Nuclear Power Plant. Therefore, our results may underestimate, potential confounding. Finally, we were unable to obtain the mea- rather than overestimate, the effects of the disaster. Second, surements of 3-year-old health examination from all participants.

Table 4 Differences in basic characteristics between participating and non-participating municipalities in control prefectures.

Participating municipalities (n ¼ 21) Non-participating municipalities (n ¼ 79)

Municipality Populationa Number of Number of Birth rateb Municipality Populationa Number of Number of Birth rateb householdsa birthsb householdsa birthsb Aomori Prefecture Aomori Prefecture Yomogida 2896 957 22 5.6 Aomori 287,622 118,279 2006 6.8 Sotogahama 6197 2573 20 7.7 Hirosaki 177,549 71,171 1252 5.2 Fukaura 8423 3304 33 5.4 Hachinohe 231,379 93,726 1798 2.1 Nakadomari 11,205 4111 47 5.2 Kuroishi 34,293 11,771 270 7.0 Shichinohe 15,719 5585 76 3.7 Goshogawara 55,171 21,136 348 3.1 Tohoku 17,969 5980 135 7.0 Towada 63,454 25,509 453 7.0 Shingo 2510 831 11 2.6 Misawa 40,223 16,377 410 7.8 Mutsu 58,506 24,446 437 5.9 Tsugaru 33,326 10,979 185 10.0 Hirakawa 32,130 10,130 193 6.9 Hiranai 11,148 3968 60 2.5 Imabetsu 2747 1289 6 7.5 Ajigasawa 10,131 3851 47 8.2 Nishimeya 1415 488 15 6.5 Fujisaki 15,180 4941 108 4.3 Owani 9684 3419 26 4.5 Inakadate 7783 2382 60 5.3 Itayanagi 13,937 4680 82 4.2 Tsuruta 13,400 4384 93 6.2 Noheji 13,520 5542 98 4.4 Rokunohe 10,423 3570 65 6.8 Yokohama 4535 1786 22 4.0 Rokkasho 10,538 4683 92 10.1 Oirase 24,220 8635 198 7.1 Oma 5220 2161 36 4.8 Higashidori 6604 2578 51 6.2 Kazamaura 1977 822 7 4.7 Sai 2152 913 6 7.3 Sannohe 10,150 3758 58 8.4 Gonohe 17,433 6126 116 7.4 Takko 5553 2005 25 5.9 Nanbu 18,319 6420 84 7.3 Hashikami 14,008 5682 75 3.1 H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142 141

Table 4 (continued )

Participating municipalities (n ¼ 21) Non-participating municipalities (n ¼ 79)

Municipality Populationa Number of Number of Birth rateb Municipality Populationa Number of Number of Birth rateb householdsa birthsb householdsa birthsb Akita Prefecture Akita Prefecture Noshiro 54,805 22,750 270 4.8 Akita 316,808 135,709 2221 6.9 Odate 74,049 28,781 429 5.6 Yokote 91,663 31,873 538 5.7 Yuzawa 46,909 16,250 241 5.0 Oga 29,123 11,596 126 4.1 Kazuno 31,762 11,659 190 5.8 Katagami 33,171 12,392 208 6.2 Yurihonjo 79,573 28,854 513 6.3 daisen 82,705 28,630 524 6.2 Mitane 17,050 6266 84 4.7 Kitaakita 33,099 12,452 176 5.1 Ogata 3087 801 19 6.1 Nikaho 25,426 9035 129 4.9 Misato 20,060 6190 96 4.6 Senboku 27,226 9741 124 4.4 Kosaka 5432 2284 28 4.9 Kamikoani 2363 932 8 3.1 Fujisato 3405 1227 12 3.3 Happou 7291 2829 26 3.4 Gojome 9466 3744 50 5.0 Hachirogata 6044 2264 32 5.1 Ikawa 5004 1586 27 5.2 Ugo 15,240 4913 90 5.7 Higashinaruse 2652 842 16 5.8

Yamagata Prefecture Yamagata Prefecture Kaminoyama 31,584 10,724 194 6.0 Yamagata 252,453 100,669 2043 8.0 Higashine 47,865 15,487 436 9.2 Yonezawa 86,010 32,991 608 7.0 Asahi 7122 2243 35 4.7 Tsuruoka 129,630 45,332 897 6.8 Oguni 7869 2841 49 5.9 Sakata 106,267 39,308 734 6.8 Mikawa 7728 2219 60 7.8 Shinjo 36,904 12,976 297 7.9 Shonai 21,669 6638 142 6.4 Sagae 41,266 13,073 315 7.6 Murayama 24,696 7712 147 5.7 Nagai 27,716 9114 203 7.1 Tendo 62,236 21,448 515 8.3 Obanazawa 16,962 5109 107 6.0 Nanyo 32,284 10,697 226 6.9 Yamanobe 14,372 4438 86 5.8 Nakayama 11,366 3466 53 4.5 Kahoku 19,046 5868 129 6.7 Nishikawa 5640 1779 23 3.9 Oe 8478 2631 57 6.5 Oishida 7359 2143 44 5.8 Kaneyama 5829 1643 48 7.9 Mogami 8908 2674 61 6.5 Funagata 5631 1620 35 6.0 Mamurogawa 8136 2520 66 7.7 Okura 3413 1017 20 5.6 Sakegawa 4315 1246 29 6.4 Tozawa 4773 1389 23 4.6 Takahata 23,887 7215 164 6.8 Kawanishi 15,756 4550 96 5.8 Shirataka 14,271 4433 84 5.7 Iide 7304 2197 56 7.4 Yusa 14,212 4510 77 5.2

a Population and number of households are based on 2015 National population census and cited from Aomori Prefectural Government, Akita Prefectural Government, and Yamagata Prefectural Government's Web pages. b Number of births and birth rate are cited from 2013 health statistics of Aomori Prefecure, 2013 health statistics of Akita Prefecture, and 2013 statistical yearbook of Yamagata Prefecture.

Because the timing of 3-year-old health examinations varies by relation to the Great East Japan Earthquake. By providing scientific municipality, 3052 children in 68 municipalities were not sched- data and interpretation of the findings, our survey results uled to undergo the examinations at the time of survey. This should contribute invaluable information regarding the health impacts on be kept in mind when analyzing the data and interpreting the re- children of the Great East Japan Earthquake for health care prac- sults from the 3-year-old health examinations. titioners, parents, and public policy makers. We conducted two surveys that collected different kinds of information. The present survey acquired birth information, methods Conflicts of interest of nutrition, and head circumference, whereas the nationwide nursery school survey12 collected information on the presence of None declared. diseases, change of residence, and personal experience with the disaster. The results from these two surveys are expected to provide strong evidence both in combination as well as through indepen- Acknowledgements dent analyses of each survey. In conclusion, the present survey is one of the largest surveys The present survey was conducted as a part of the “surveillance ever conducted on physical growth among preschool children in study on child health in the Great East Japan Earthquake disaster 142 H. Matsubara et al. / Journal of Epidemiology 27 (2017) 135e142 area” and supported in full by funding from the Health and Labour 123456789/243/1/PDF%205.5CHAPTER%20ON%20HUMAN%20GROWTH% Sciences Research Grant (H24-jisedai-shitei-007, fukkou). 20FOR%20CSIR.pdf. 8. Kato N, Takimoto H, Yokoyama T, Yokoya S, Tanaka T, Tada H. Updated Japa- The following are members of the working group for childhood nese growth references for infants and preschool children, based on historical, physical developmental evaluation based on the grant above: Shi- ethnic and environmental characteristics. Acta Paediatr. 2014;03:e251e61. geo Kure (PI), Professor and Chairman, Department of Pediatrics, 9. National Institute of Public Health [Internet]. Wako: Physical growth assess- ment manual [cited 2015 Aug 3]. Available from: http://www.niph.go.jp/ Tohoku University; Susumu Yokoya, Department of Medical Sub- soshiki/07shougai/hatsuiku/index.files/katsuyou_130805. pdf (in Japanese). specialties, National Center for Child Health and Development; 10. The Children’s Health Fund and the National Center for Disaster Preparedness, Toshiaki Tanaka, President, Japanese Association for Human Aux- Columbia University Mailman School of Public Health [Internet]. New York. Legacy of shame: The on-going public health disaster of children struggling in ology; Noriko Kato, Professor, Department of Early Childhood and post-Katrina Louisiana. [revised 2009 Jan 12, cited 2015 Aug 3]. Available from: Elementary Education; Jumonji University; Tsuyoshi Isojima, As- http://www.childrenshealthfund.org/sites/default/files/Legacy-of-Shame-BR- sistant Professor, Department of Pediatrics, The University of White-Paper-Dec-2009.pdf.pdf. 11. Speier AH. Psychosocial Issues for Children and Adolescents in Disasters. second Tokyo; Shoichi Chida, Professor and Chairman, Department of Pe- ed. 2000. diatrics, Iwate Medical University; Mitsuaki Hosoya, Professor and 12. Matsubara H, Ishikuro M, Kikuya M, et al. Design of the nationwide nursery Chairman, Department of Pediatrics, Fukushima Medical Univer- school survey on child health throughout the Great East Japan Earthquake. J e sity; Atsushi Ono, Research Associate, Department of Pediatrics, Epidemiol. 2016;26:98 104. http://dx.doi.org/10.2188/jea.JE20150073 (Epub 2015 Oct 10). Fukushima Medical University; Zentaro Yamagata, Professor, 13. Maternal and Child Health Act, L. No. 141. Aug 18, 1965. Department of Health Sciences, University of Yamanashi; Hiroshi 14. Nakamura Y. Maternal and child health handbook in Japan. Jpn Med Assoc J. e Yokomichi, Assistant Professor, Department of Health Sciences, 2010;53:259 265. 15. Kato N, Takimoto H, Eto T. The regional difference in children's physical growth University of Yamanashi; Soichiro Tanaka, Associate Professor, between Yaeyama Islands of Okinawa Prefecture and national survey in Japan. Department of Pediatrics, Tohoku University; Shinichi Kuriyama, J Natl Inst Public Health. 2012;61:448e453. Professor, International Research Institute of Disaster Science 16. Sakihara E, Kinjo R, Tamashiro T, Inoha J, Goya E, Uehara H. Local differences in Japanese children's physical development over 55 Years using body mass index (IRIDeS), Tohoku University; Masahiro Kikuya, Associate Professor, cross-sectional analysis. Ningen Dock. 2006;21:23e27. Tohoku Medical Megabank Organization (ToMMo), Tohoku Uni- 17. Yokoya M. Geographic variation in the body size of Japanese students and its versity; Mami Ishikuro, Assistant Professor, ToMMo, Tohoku Uni- analysis by mesh climate data. Jpn J Nutr Diet. 2010;68:263e269 (in Japanese). 18. Yokoya M, Higuchi Y. Geographical differences in the population-based cross- versity; and Hiroko Matsubara, Postdoctoral Research Associate, sectional growth curve and age at peak height velocity with respect to the IRIDeS, Tohoku University. prevalence rate of overweight in Japanese children. Int J Pediatr. 2014;2014: The authors wish to express their appreciation to all persons 867890. 19. 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