Patients’ self-perceived awareness of drug–drug and drug–food interactions: A cross-sectional study in southern Saudi Arabia

Abstract: Background: Patients’ self-perceived awareness of drug–drug interactions (DDIs) and drug–food interactions (DFIs) is important for medication safety, yet interaction-related counseling remains limited. Objectives: To assess patients’ self-perceived awareness of DDIs/DFIs and identify sociodemographic correlates of insufficient awareness in tertiary outpatient pharmacies of southern Saudi Arabia. Methods: A cross-sectional survey was conducted at two tertiary hospitals over six months. Adults ≥18 years attending outpatient pharmacies were recruited via consecutive sampling. A structured, self-administered questionnaire, refined by expert review, collected data on demographics, awareness, attitudes and behaviors. Insufficient self-perceived awareness was defined a priori as a moderate, weak, or very weak rating on a five-point Likert scale. Internal consistency was assessed via Cronbach’s alpha. Associations were examined using χ² with Cramer’s V and multivariable logistic regression estimated adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results: Of 401 patients approached, 353 consented; after excluding 12 records aged <18 years, 341 participants (52.8% female) formed the analytic sample. Overall, 22.3% (95% CI 18.2–27.0) reported insufficient awareness. Counseling on DDIs (7.6%) and DFIs (6.2%) was uncommon; DDIs (54.0%) and DFIs (51.3%) were the most frequent unclear topics. A two-item attitudinal subscale showed acceptable internal consistency (α = 0.75). After adjustment, only older age remained an independent predictor (aOR ≥51 vs 18–40 = 8.33, 95% CI 3.10–22.40), while education was not (aOR 1.11, 0.57–2.16). Conclusion: Insufficient self-perceived awareness of DDIs/DFIs was substantial. Older age, rather than education, was the only independent correlate, suggesting the unadjusted education association may be age-confounded. Targeted, age-sensitive pharmacist-led counseling may improve medication safety. Findings are exploratory given reliance on a self-perceived measure.