Individual and socioeconomic contextual effects on depressive symptom in Korea: multilevel analysis of cross-sectional nationwide survey.

This study was aimed to examine the relationship between individual, socioeconomic context and depressive symptom among Korean population. Data were the Korean Community Health Survey (KCHS), a nationwide survey collected from 253 local communities including 230,715 adults aged 19 yr or over. To identify depressive symptom, the Center for Epidemiologic Studies Depression scale (CES-D) was used. This study employed multilevel logistic regression to analyze the hierarchical data that included individual and community level variables. The results of this study showed that people in the highest level of community income had a higher risk of depressive symptom compared with people in the lowest (OR, 1.6; 95% CI, 1.4-1.9). In a chi-square test for trend, the prevalence of depressive symptom was significantly increased with increased level of community income among all groups of the family income (P<0.001). Moreover a significant interaction was found between household income and community mean income (OR, 0.98; 95% CI, 0.97-0.99). Among individual level variables, age, sex, education, income, living alone, and the number of illnesses were associated with depressive symptom. This study identified that the level of community income has an inverse association, and its effect is especially stronger among low income individuals.