Open AccessSize of company of the longest‐held job and mortality in older Japanese adults: A 6‐year follow‐up study from the Japan Gerontological Evaluation Study
Author(s) -
Kanamori Satoru,
Tsuji Taishi,
Takamiya Tomoko,
Kikuchi Hiroyuki,
Inoue Shigeru,
Takagi Daisuke,
Kai Yuko,
Yamakita Mitsuya,
Kameda Yoshito,
Kondo Katsunori
Publication year - 2020
Publication title -
journal of occupational health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 59
ISSN - 1348-9585
DOI - 10.1002/1348-9585.12115
Subject(s) - hazard ratio , demography , proportional hazards model , longitudinal study , medicine , confidence interval , inequality , gerontology , psychology , surgery , mathematical analysis , mathematics , pathology , sociology
Objectives Very few longitudinal studies have investigated the question of whether differences in company size may give rise to health inequalities. The aim of this study was to examine the relationship between company size of the longest‐held job and mortality in older Japanese adults. Methods This study used longitudinal data from the Japan Gerontological Evaluation Study. Surveys were sent to functionally independent individuals aged 65 or older who were randomly sampled from 13 municipalities in Japan. Respondents were followed for a maximum of 6.6 years. The Cox proportional hazards model was used to calculate mortality hazard ratios (HRs) for men and for women. Analysis was carried out on 35 418 participants (197 514 person‐years). Results A total of 3935 deaths occurred during the 6‐year follow‐up period. Among men, in Model 1 that adjusted for age, educational attainment, type of longest‐held job, and municipalities, mortality HRs decreased significantly with increasing size of company ( P for trend = .002). Compared to companies with 1‐9 employees, the mortality HR (0.78, 95% confidence interval: 0.68‐0.90) was significantly lower for companies with 10 000 or more employees. However, there were no significant differences among women ( P for trend = .41). Conclusions In men, mortality in old age may decrease with increasing size of company of the longest‐held job. To reduce health inequalities in old age due to differences in size of company, studies should be conducted to determine the underlying mechanisms and moderating factors and those findings should be reflected in labor policies and occupational health systems.