Relationship Between Health Literacy and Rational Drug Use in Primary Care

Aim: To determine health literacy and rational drug use levels among adults attending a primary care family health center, quantify their association, and identify independent predictors using multivariable regression analysis. Methods: A cross-sectional study was conducted with 290 adults at a family health center in a metropolitan city in Türkiye (November 2022-January 2023). The Health Literacy Scale (25-125) and the Rational Drug Use Scale (0-42) were administered face-to-face. Three multivariable regression models were constructed: linear regression for Rational Drug Use Scale score (Model 1), binary logistic regression for adequate Rational Drug Use Scale (score≥35; Model 2), and linear regression for Health Literacy Scale score (Model 3). Bootstrap resampling (1,000 iterations) was used for internal validation. Results: Mean Rational Drug Use Scale score was 36.74±5.07; 71.0% had adequate Rational Drug Use knowledge. Mean Health Literacy Scale score was 91.33±21.64. A moderate positive correlation was found. Health Literacy Scale total score and university-level education were the strongest independent predictors of Rational Drug Use Scale. Each one-point increase in Health Literacy Scale was associated with 4.2% higher odds of adequate Rational Drug Use. The logistic model showed excellent discrimination. Conclusion: Health literacy is an independent predictor of rational drug use in primary care. Education and younger age are the main shared determinants. Structured health literacy interventions in family health centers may improve rational medication behaviours.