Age- versus time-comparative self-rated health in Hong Kong Chinese older adults

OBJECTIVES: The main objectives were to examine the relation between age-comparative (self vs others of same age) self-rated health (SRH) and time-comparative (self this year vs last year) SRH, and to evaluate which was more strongly associated with specific physical health problems. METHODS: Cross-sectional data on two SRH measures and various physical health problems from 18749 male and 37413 female clients aged 65 or over from 18 Elderly Health Centres in Hong Kong were analysed using logistic regression with adjustment for potential confounders. RESULTS: Men were more likely to report 'better' and less likely to report 'worse' SRH than women. 'Normal' was the most common option but the proportions choosing this decreased with age on both SRH measures. There was a fairly weak but statistically significant correlation between these two measures, with Kappa coefficients of 0.125 and 0.167 for men and women, respectively. For both men and women, there were significantly positive linear trends between age-comparative SRH options from 'better' to 'worse' and physical health problems, such as respiratory diseases, musculoskeletal diseases, any active chronic diseases, functional disability, depressive symptoms, taking medication regularly, and admission to hospital last year. However, for time-comparative SRH, those who rated 'normal' had the smallest odds ratios in all of the physical health problems above than those who rated 'better' or 'worse'. CONCLUSIONS: The two SRH measures correlated with each other weakly but significantly. Age-comparative SRH was linearly, and time-comparative SRH was curvilinearly associated with physical health problems.