We conducted a multilevel analysis to identify the individual- and school-level factors that affect Korean high school students' tooth brushing, soda intake, smoking, and high-intensity physical activity. We sampled 27,919 high school students from the 15th Korea Youth Risk Behavior Web-Based Survey. The individual-level variables included demographic, socioeconomic, and health-related factors. The school-level variables included school system and school type. Regarding the individual-level factors, economic level and academic performance had a significant effect on health behavior when the demographic variables were adjusted. In the final model, the school-level factors had a significant effect on health behavior. The odds ratio (OR) of brushing less than twice a day in vocational schools compared to general schools was 1.63 (p < 0.001), and the OR of soda intake more than three times a week in vocational schools was 1.33 (p < 0.001). In addition, the OR of smoking in vocational schools was 2.89 (p < 0.001), and the OR of high-intensity physical activity in vocational schools was 0.80 (p < 0.001). Therefore, both individual- and school-level factors affect Korean students' health behaviors. A school-based comprehensive health promotion strategy should be developed that considers schools' characteristics to equip all students with health awareness, regardless of socioeconomic status.
Keywords: adolescent health; health behavior; multilevel analysis; school-based health services; social health determinants.