Rational drug use and associated factors in pulmonology outpatients: a cross-sectional study

Objective: Rational drug use (RDU) refers to administering medications that are appropriate to patients’ clinical needs, in doses that meet their individual needs for a sufficient duration, and at the lowest possible cost. Despite the clinical importance of RDU, irrational drug use remains prevalent, particularly in pulmonology patients. In this context, the objective of this study is to evaluate RDU knowledge and identify associated sociodemographic and clinical factors in pulmonology outpatients. Methods: The sample of this cross-sectional, single-center study consisted of 317 outpatients aged 18 years or older who presented to a secondary chest diseases hospital between February and May 2023. The patients were assessed using a structured questionnaire containing items on their sociodemographic and general health characteristics and the validated 21-item Rational Drug Use Scale (RDUS). The collected data were analyzed using parametric and chi-square tests, as well as correlation and logistic regression analyses. Results: The mean age of the study sample, 59.6% of which were females, was 50.0 ± 13.0 years. Of the 317 patients, 78.9% had chronic diseases, and 38.8% were taking ≥5 medications (polypharmacy). The mean RDUS score of the sample was 29.78±4.77, indicating insufficient knowledge. The mean RDUS score of the patients aged ≤45 years was significantly higher than that of those aged >45 years (p=0.007). The mean RDUS score of the patients living in urban areas was significantly higher than that of those living in rural areas (p=0.031). A strong correlation was found between patients’ education level and RDUS score. Accordingly, the mean RDUS score of patients with higher education was significantly higher than that of patients with other education levels (p=0.001). Multivariate analysis revealed higher education levels ([Odds Ratio (OR)=3.45, p=0.005], living in urban areas [OR=2.46, p=0.031], and young age [