Associations of socioeconomic and religious factors with health: a population-based, comparison study between China and Korea using the 2010 East Asian social survey

BACKGROUND: Cross-national comparisons of the associations of socioeconomic and religious factors with health can facilitate our understanding of differences in health determinants between countries and the development of policies to reduce health differentials appropriate to each country. However, very few such studies have been conducted in East Asia. METHODS: This study set out to compare the associations of socioeconomic and religious factors with health in China and Korea using the 2010 East Asian Social Survey, which was based on nationally representative samples. The study participants included 4980 individuals, 3629 in China and 1351 in Korea, aged ≥20 years. The dependent variable, individuals’ self-rated health, was categorized into poor, good, and excellent. Socioeconomic (education, employment, household income, and self-assessed social class) and religious factors (affiliation) were used as independent variables of interest. A multinomial logistic regression was performed with and without adjustments for factors such as demographics, health-related risks, the health system, and social capital. RESULTS: According to the results, China had a higher proportion of individuals who reported excellent health than did Korea (57.4% vs. 52.0%). After adjusting for all studied confounders, we found that the employment, household income, and social class gradient in health were significant in China, whereas the education and religion gradients in health were significant in Korea. For example, the odds ratio for poor health versus excellent health among those in the highest social class was 0.47 (95% CI, 0.27–0.84), compared to that of people in the lowest social class in China; and this odds ratio in people with college education or higher was 0.28 (95% CI, 0.14–0.59) compared to that of people with elementary school education or lower in Korea. CONCLUSIONS: These findings demonstrate the important role of socioeconomic and religious factors in health in China and Korea as well as clear differences in this regard. Further cross-national studies are needed to provide a better understanding of the relationship between socioeconomic and religious factors and health and to draft appropriate health improvement policies in both countries. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12889-018-6380-y) contains supplementary material, which is available to authorized users.