Industrial Health
Total Page:16
File Type:pdf, Size:1020Kb
Advance Publication INDUSTRIAL HEALTH Received: June 28, 2020 Accepted: September 15, 2020 J-STAGE Advance Published Date: September 26, 2020 1 Article type: Original 2 Title: Gastric Cancer Mortality Rates by Occupation and Industry among Male and Female 3 Workers Aged 25–64 Years in Japan 4 5 Running title: GASTRIC CANCER MORTALITY BY OCCUPATION IN JAPAN 6 Authors and Affiliations: 7 Yoko YOSHINAGA 8 Graduate School of Medicine, International University of Health and Welfare, Japan 107-8402 9 10 Hirokazu TANAKA 11 Department of Public Health, Erasmus University Medical Center, 3000 CA Rotterdam, The 12 Netherlands 13 14 Koji WADA 15 Graduate School of Medicine, International University of Health and Welfare, Japan 16 17 Shunya IKEDA 18 Graduate School of Medicine, International University of Health and Welfare, Japan 19 20 Corresponding author: Koji WADA 21 Email address: [email protected] 22 Mailing address: 4-1-26 Akasaka, Minato City, Tokyo, Japan 107-8402 23 Phone number: +81-3-5574-3900 24 Fax number: +81-3-5574-3901 25 26 Number of text pages: 26 1 27 Number of tables: 4 28 Word count: 4704 (including REFERENCES and APPENDICES) 29 30 Received: June 28, 2020 31 Accepted: September 15, 2020 32 Advanced Epub: September 26, 2020 33 34 2 35 Abstract 36 Differences in risk for gastric cancer exist among occupations and industries in Japan. Using a 2015 37 national dataset, we estimated the mortality rates due to gastric cancer in Japanese male and female 38 workers aged 25–64 years. Regression models were used to estimate the mortality rate ratios 39 separately for men and women with adjustment for age. The occupation with the highest risk ratio was 40 “Service” in men (2.06, 95% confidence interval: 1.63–2.61) and “Construction and Mining” in 41 women compared with “Sales”. For industries, workers in “Mining”, “Electricity, Gas, Heat supply 42 and Water”, “Fisheries”, “Agriculture and Forestry”, and “Construction” had a higher mortality risk. 43 Our results showed that occupations and industries with higher mortality rates in men had the same 44 trend as the results from 2010, and occupations and industries with higher mortality rates in women 45 were almost the same as those in men. The analyses also indicated that managerial and professional 46 workers in Japan had higher mortality as opposed to developed Western countries. In conclusion, this 47 study suggests that occupations and industries still impact men and women’s health in terms of 48 mortality due to gastric cancer in Japan. 49 Keywords: mortality rate; occupational health; gastric cancer; industrial health; mortality rate 50 ratio by male and female 51 3 52 INTRODUCTION 53 Mortality differences among occupations or industries have been reported in many countries1-6) 54 and these differences caused by some working environmental issues in occupations or industries 55 remain one of the greatest challenges for occupational health. In Japan, recent evidence suggested the 56 differences in mortality rates among occupations and industries1, 6, 7). Eguchi et al.8) demonstrated that 57 Japanese male workers in service, administrative and managerial positions, agriculture, forestry and 58 fisheries, and professional and engineering occupations had higher relative mortality risks due to 59 gastric cancer in their occupations, and that mining, electricity and gas, fisheries, and agriculture and 60 forestry had the higher mortality risks among the industries. 61 62 There are still risk factors for gastric cancer that can be eliminated by social initiatives. 63 Helicobacter pylori infection is one of the major risk factors for gastric cancer9), especially in men10). 64 Treatment for Helicobacter pylori infection has been covered by public health insurance in Japan 65 from late 200011, 12) and the proportion of Helicobacter pylori carriers is decreasing gradually now in 66 Japan13). Additionally, Japan has a lower cancer screening rate among developed OECD countries14). 67 Furthermore, a report has been published that determined the 5-year survival rates for people with 68 gastric cancer are 94.7% if their cancer is stage I at diagnosis whereas survival rates drop to 8.9% if 69 the cancer is detected at stage IV15). On the basis of Japan’s lower cancer screening rate and the 70 aforementioned report, the Japanese government is developing health policies to promote cancer 71 screening to achieve a 50% screening rate16). 72 73 In addition to the situation, the working environment and the industrial structure in Japan are 74 steadily changing according to the aging of the Japanese population. The percentage of female 75 workers aged 20 to 64 years is currently about 70 % in Japan, and the number of female workers is 76 increasing17, 18). On the other hand, the overall regular employment rate in Japan is slightly 77 decreasing19). 4 78 79 Despite such changes in Japan, there is no research to evaluate the mortality rates and risk ratios 80 in Japanese female workers, nor the evidence that shows the differences in mortality rates among 81 occupations and industries in Japanese male workers using the latest data. This study aimed to 82 evaluate the differences of mortality risk due to gastric cancer among occupations and industries in 83 male workers as follow-up data, and in female workers as the first evidence in Japan using the 84 national dataset titled “Vital Statistics in fiscal year 2015: Occupational and Industrial Aspects20)” by 85 the Japanese Ministry of Health, Labour, and Welfare and “2015 Population Census21)” by the 86 Statistics Bureau of the Japanese Ministry of Internal Affairs and Communications. 5 87 SUBJECTS AND METHODS 88 Data source 89 All the analyses were performed using the national dataset titled “Vital Statistics in fiscal year 90 2015: Occupational and Industrial Aspects” by the Japanese Ministry of Health, Labour, and Welfare. 91 Occupation and industry specific death rates were calculated based on the 2015 National Population 92 Census, which is conducted at 5-year intervals on October 1st on each occasion in Japan. 93 94 Measurements 95 Japanese death certificate data include underlying causes of death and are completed by 96 physicians based on the records of events leading to deaths. They are coded according to the 97 International Classification of Diseases 10th Revision (ICD-10). Individuals diagnosed with gastric 98 cancer (ICD-10 codes, C16.0–16.9) were included in the analyses. 99 100 The occupation and industry of deceased individuals were required to be reported to the local 101 government offices by family members throughout the analysis years in Japan. Family members 102 choose one occupation and industry categories of the deceased individuals from lists of occupation 103 and industry and fill out the death report form within 7 days after the death. The occupation list 104 consists of 11 occupations: administrative and managerial; professional; clerical; sales; services; 105 security; agriculture, forestry and fisheries; manufacturing; transport; construction and mining; and 106 carrying, cleaning and packaging. The industry list consists of 19 industries: agriculture, fisheries, 107 mining, construction, manufacturing, electricity and gas, information, transport, wholesale and retail, 108 finance, real estate and rental, research and professional services, accommodation and dining services, 109 amusement services, education, medical and welfare, compound services, other service industries, and 110 government. These categories are based on the General Principles for the Japan Standard 111 Occupational Classification, the Underlying Principles of the Classification, which are documented 112 based on the International Standard Classification of Occupations22) (ISCO-08) and the International 6 113 Standard Industrial Classification of All Economic Activities23) (ISIC). The detail of the classifications 114 is shown in Appendices. 115 116 Statistical analysis 117 Data for Japanese male and female workers aged 25–64 years in 2015, grouped into 5-year age 118 intervals, were used in the analyses. The numbers of deceased individuals due to gastric cancer in 119 each age group by the occupation and industry categories were extracted from the Japanese national 120 census report. The numbers of employees in each occupation or industry category from the national 121 census in 2015 were used as the denominator and the numbers of deaths as the numerator for 122 calculating the mortality rates. The rates are standardized by the age of the Japanese standard 123 population in 1985, which is commonly used to compare health statistics across various years in Japan. 124 125 Individual data were generated according to the death rates of each occupation, industry, age, and 126 sex category to perform the regression with the adjustment for age. Separate regression models by sex 127 were used to calculate the mortality rate ratios (MRRs) with corresponding 95% confidence intervals 128 (95% CIs) for death due to gastric cancer in each occupation or industry with the reference of “Sales” 129 or “Wholesale and Retail trade”, respectively. 130 131 As the explanatory covariate, the categorized age and occupation or industry were included in 132 each model. The reference category of “25–29 years” is assigned a value of 0, and other categories 133 follow in succession (e.g., “30–34 years” and “35–39 years” are assigned values of 1 and 2, 134 respectively) in dummy coding. In the model for occupation, the reference category is assigned a 135 value of 0 and other categories are assigned a value of 1. All analyses were performed using STATA 136 version 14 (StataCorp LP; College Station, TX, USA). This study was approved by the ethical 137 committee at the International University of Health and Welfare in 2019 (19-Im-010) and supported 138 by JSPS KAKENHI (Grant Number 17K09184). 139 7 140 RESULTS 141 Table 1 shows the number of deaths due to gastric cancer and the mortality rates in male and 142 female workers aged 25–64 years by occupation during 2015 in Japan.