PLoS ONE (Jan 2012)

Sex/gender and socioeconomic differences in the predictive ability of self-rated health for mortality.

  • Akihiro Nishi,
  • Ichiro Kawachi,
  • Kokoro Shirai,
  • Hiroshi Hirai,
  • Seungwon Jeong,
  • Katsunori Kondo

DOI
https://doi.org/10.1371/journal.pone.0030179
Journal volume & issue
Vol. 7, no. 1
p. e30179

Abstract

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BACKGROUND: Studies have reported that the predictive ability of self-rated health (SRH) for mortality varies by sex/gender and socioeconomic group. The purpose of this study is to evaluate this relationship in Japan and explore the potential reasons for differences between the groups. METHODOLOGY/PRINCIPAL FINDINGS: The analyses in the study were based on the Aichi Gerontological Evaluation Study's (AGES) 2003 Cohort Study in Chita Peninsula, Japan, which followed the four-year survival status of 14,668 community-dwelling people who were at least 65 years old at the start of the study. We first examined sex/gender and education-level differences in association with fair/poor SRH. We then estimated the sex/gender- and education-specific hazard ratios (HRs) of mortality associated with lower SRH using Cox models. Control variables, including health behaviors (smoking and drinking), symptoms of depression, and chronic co-morbid conditions, were added to sequential regression models. The results showed men and women reported a similar prevalence of lower SRH. However, lower SRH was a stronger predictor of mortality in men (HR = 2.44 [95% confidence interval (CI): 2.14-2.80]) than in women (HR = 1.88 [95% CI: 1.44-2.47]; p for sex/gender interaction = 0.018). The sex/gender difference in the predictive ability of SRH was progressively attenuated with the additional introduction of other co-morbid conditions. The predictive ability among individuals with high school education (HR = 2.39 [95% CI: 1.74-3.30]) was similar to that among individuals with less than a high school education (HR = 2.14 [95% CI: 1.83-2.50]; p for education interaction = 0.549). CONCLUSIONS: The sex/gender difference in the predictive ability of SRH for mortality among this elderly Japanese population may be explained by male/female differences in what goes into an individual's assessment of their SRH, with males apparently weighting depressive symptoms more than females.