Subjective social status and trajectories of self-rated health status: a comparative analysis of Japan and the United States

Background Japanese society is more egalitarian than the United States as is reflected by the lower degree of prevalence of social inequalities in health. We examined whether subjective socioeconomic status is associated with different trajectories of self-rated health (SRH), and whether this relationship differs between the United States and Japan. Methods We analyzed the responses of 3968 Americans from the survey Midlife in the United States, 2004-06, and the responses of 989 Japanese from the survey Midlife in Japan, 2008. We conducted a multilevel analysis with three self-ratings of health (10 years ago, current and 10 years in the future) nested within individuals and nested within 10 levels of subjective social status. Age, sex, educational level and subjective financial situation were adjusted. Results After making statistical adjustments for confounding variables, respondents in Japan continued to report lower average levels of health. However, the rate of expected decline in SRH over the next decade was strongly socially patterned in the United States, whereas it was not in Japan. Conclusion The Japanese showed no disparity in the anticipated trajectory of SRH over time, whereas the Americans showed a strong social class gradient in future trajectories of SRH.