Reversal pattern of health inequality: New evidence from a large-scale national survey in Japan

Despite extensive evidence for a positive association between socio-economic status (SES) and health, some studies have shown that this well-established pattern of health inequality is reversed in Japan due to individuals of high SES working in stressful workplace environments. High-SES workers in Japan generally belong to a lifetime employment system (LES) in large companies. Thus, in this study, individuals who had been working for a single company for several decades at the time of a 2005 survey (LES workers) were compared with other workers by logistic regression and ordinary least squares regression. These analyses showed that LES workers had 36% more household savings. However, despite their relatively high income, the LES workers were more likely to develop diabetes (odds ratio 1.134: 95% CI 1.022-1.259) and hyperlipidemia (odds ratio 1.184: 95% CI 1.079-1.300). Among women, LES workers were at higher risk of developing cancer (odds ratio 1.570: 95% CI 1.174-2.098). In addition, these effects were consistently found in subsequent surveys between 2006 and 2015, suggesting that the LES had long-term adverse effects on health. These results taken together show that career trajectory is an important determinant of health inequality in the elderly population. (C) 2020 Elsevier B.V. All rights reserved.