The purpose of this study is to examine how much variance in self-rated health is attributable to household and administrative-area levels. Additionally, the study investigates the association between physical activity and self-rated health while adjusting for various covariates at the individual, household, and district levels in Seoul, South Korea. A cross-sectional study of the 2009 Seoul Welfare Panel Study conducted by Seoul Welfare Foundation was utilized. The final sample included 7,761 individuals within 3,617 households in 25 administrative areas. Three-level random intercept logistic models were fitted. The results showed that a small proportion (3.52%) of variance in self-rated health was attributed to the administrative-area level, while a relatively large proportion (33.78%) was attributed to the household level. This study also found a positive association between physical activity and self-rated health, even after controlling for covariates at multiple levels. The results indicated that public health interventions promoting physical activity may have a beneficial effect on individual health. Additionally, public health interventions for improving individual health may not be efficient if directed only at the administrative-area level, as only a small portion of variance in self-rated health was attributable to this level.
Keywords: Physical activity; household; multilevel analysis; self-rated health; social environment.