Individual vulnerabilities and community context: Multilevel factors associated with self-rated oral health in adults with diabetes in South Korea

Abstract

Adults with diabetes mellitus are at an increased risk of poor oral health; however, how individual- and community-level factors jointly contribute to oral health disparities in this population remains unknown. This study aimed to examine multilevel determinants of self-rated oral health among adults with diabetes in South Korea. A cross-sectional analysis was conducted using data from 21,996 adults aged ≥19 years with physician-diagnosed diabetes who participated in the 2021 Korea Community Health Survey. Self-rated oral health was dichotomized as good or poor. Individual- and community-level variables representing health behaviors, clinical care, social and economic factors, and physical environment were selected, guided by the County Health Rankings model. Multilevel logistic regression models accounted for clustering within administrative districts. At the individual level, poorer self-rated oral health was significantly associated with sociodemographic disadvantages (older age, male sex, not married, lower education, and economic inactivity), poorer general health status, adverse health behaviors (lifetime smoking and inadequate toothbrushing), and unmet dental care needs (all p < 0.05). At the community level, greater accessibility to public transportation was associated with better self-rated oral health (OR = 0.997, 95% CI: 0.993–1.000), whereas a higher prevalence of moderate-intensity physical activity was associated with poorer oral health (OR = 1.006, 95% CI: 1.000–1.011). Self-rated oral health among adults with diabetes is influenced by individual-level socioeconomic and behavioral factors alongside selected community-level contextual conditions. Multilevel strategies integrating oral health into chronic disease management are required, while addressing structural barriers to dental care.