Abstract
OBJECTIVES: The purpose of this study was to estimate the effects of health-risk behaviors, alone and in combination, on health outcomes. METHODS: This study used sample cohort data provided by the National Health Insurance Service focusing on the use of hospital services, direct medical expenses, length of stay, and re-entry rate according to health-risk behaviors. A frequency analysis and the chi-square test were used to investigate associations between the demographic characteristics of study subjects and their health-risk behaviors. The strength of the association of each factor was calculated as the odds ratio in a crossover analysis. RESULTS: Obesity had the largest effect, especially in combination with smoking and drinking. In particular, significant associations were shown with the duration of hospitalization and direct medical expenses. After adjustment for sex, age, economic status, and pre-existing medical conditions, the duration of hospitalization was 7.37 times longer and that of medical expenses was 5.18 times higher in the obese group relative to the non-obese group. Drinking showed a statistically significant association with the number of days of hospitalization. After adjusting for the control variables, the number of hospital days was 1.24 longer in the drinking group than in the non-drinking group. CONCLUSIONS: An analysis of combinations of health risk factors showed obesity had the largest effect.