Oral Health Literacy and Self-Care Behaviors in Older Adults with Type 2 Diabetes: A Cross-Sectional Study from Rural Thailand

Objective: This study aimed to (1) assess oral health literacy (OHL) and oral health care behavior (OHCB) levels, (2) examine their correlations, and (3) identify independent predictors of OHCB among elderly patients with type 2 diabetes mellitus (T2DM) in Warin Chamrap District, Ubon Ratchathani Province, Thailand. Methods: A cross-sectional analytical study was conducted among 234 elderly T2DM patients selected by multistage random sampling from sub-district health promoting hospitals. OHL was assessed across six domains using a validated 35-item questionnaire (Cronbach’s alpha = 0.932), and OHCB was evaluated using a 10-item instrument (Cronbach’s alpha = 0.684). Data were analyzed using descriptive statistics, Spearman’s rank correlation coefficient, and hierarchical multiple linear regression. Results: Half of the participants (50.00%) demonstrated high overall OHL, with 46.15% at the moderate level. Decision-making skills were the highest-scoring OHL domain (74.36% high level). Most participants (67.52%) exhibited good OHCB. The highest-scoring OHCB item was fluoride toothpaste use (mean = 2.87, standard deviation [SD] = 0.49), while toothbrushing without adjuncts was lowest (mean = 1.71, SD = 0.75). All six OHL domains were significantly and positively correlated with OHCB ( P < 0.05, r s = 0.165–0.328). Access to health information and services showed the strongest individual correlation ( r s = 0.328, P < 0.001), and overall OHL demonstrated a moderate positive correlation ( r s = 0.405, P < 0.001). Hierarchical multiple regression confirmed that overall OHL independently predicted OHCB ( β = 0.430, P < 0.001, R 2 change = 0.156) after controlling for sociodemographic and clinical covariates. Conclusion: OHL is a significant independent predictor of OHCBs in elderly diabetic patients. Interventions targeting information access, knowledge enhancement, and practical oral hygiene skills, integrated within routine diabetes follow-up, are recommended to improve oral health outcomes in this population.