Social gradient of self-rated health in older people-the moderating/mediating role of sense of community

Abstract

Background: Social gradients of self-rated health (SRH) of older people are evident in various settings. However, it is not clear whether improving older people's sense of community (SoC) could mitigate the social gradient. Methods: People aged above 60 in five residential districts of Hong Kong were sampled using multistage sampling (n = 1,793). SoC was measured using the validated eight-item Brief Sense of Community Scale, with each item on a five-point Likert scale, forming a score from 8 to 40. SRH was considered as dichotomous (poor/not poor). Socioeconomic status (SES) was operationalised as monthly income, highest education attainment and self-rated disposable income (defined as whether the older person feel he/she has sufficient income). Causal mediation analysis using four-way decomposition was used to assess whether SoC mediates/moderates the association of SES and poor SRH. Results: A social gradient of poor SRH by all measures of SES was observed [adjusted relative risk (RR) per standard deviation income increase = 0.92; 95% confidence interval (95% CI) 0.88-0.97; RR comparing lowest to highest education= 1.77; 95% CI: 1.48-2.11; RR comparing very insufficient to very sufficient disposable income = 1.74; 95% CI: 1.48-2.05]. Causal mediation analysis showed that SoC interacts with the association of education and SRH, with higher the SoC, stronger the education gradient. Conclusions: Our findings showed a social gradient of SRH in the older population in Hong Kong. This relationship was moderated by SoC, for which higher SoC is related to stronger SES-SRH gradient.