Factors associated with poor self-rated health among middle-aged and older adults in Japan: a two-wave longitudinal study

Objectives This study examined associations between changes in socioeconomic, functional, and psychological factors and self-rated health (SRH) at Wave 2 among middle-aged and older adults in Japan. Study design A two-wave longitudinal secondary analysis of panel data collected between 2010 and 2012. Methods Participants aged ≥50 years with complete data (n = 2,573) were included. Poor SRH at Wave 2 was the outcome. Educational attainment and changes in socioeconomic, functional, and psychological factors were examined using multivariable logistic regression adjusted for baseline SRH and other covariates. Sensitivity analyses included ordinal logistic regression, an alternative SRH classification, multiple imputation, and exploratory age-stratified analyses. Results In the fully adjusted model, becoming dependent (odds ratio [OR] = 4.38, 95% confidence interval [CI]: 2.37–8.11), remaining dependent (OR = 3.34, 95% CI: 1.94–5.76), and increased psychological distress (OR = 1.13, 95% CI: 1.09–1.16) were associated with poor SRH. In the exploratory age-stratified analyses, college or higher education was associated with lower odds of poor SRH among adults aged ≥65 years. However, educational attainment was not significantly associated with SRH in the primary or ordinal analyses. Educational attainment was not significantly associated with poor SRH in the primary analysis. In age-stratified analyses, college or higher education was associated with lower odds of poor SRH among adults aged ≥65 years. Conclusions In this two-wave longitudinal study of middle-aged and older adults in Japan, changes in care needs and psychological distress were associated with SRH at Wave 2. Higher educational attainment was associated with better SRH among adults aged ≥65 years in the exploratory age-stratified analysis, although this association was not significant in the primary or ordinal analyses. Higher educational attainment was also associated with better SRH among adults aged ≥65 years.