Prevalence and Correlates of Polypharmacy, and Drug Utilization Pattern in a Semi-urban Population: Results from the Pars Cohort Study.

Background: Although polypharmacy is considered a major predictor of irrational use of drugs, little is known about polypharmacy in developing regions. We aimed to indicate the prevalence and correlates of polypharmacy and to determine the medication profile at the population level in southern Iran.

Methods: In this cross-sectional study, we analyzed data from participants of the Pars Cohort Study (PCS) (aged above 40 years, N=9269). Polypharmacy was defined as using five or more medications concurrently. A Poisson multivariable model was applied to estimate the adjusted prevalence ratios (APRs) of various risk factors. The Anatomical Therapeutic Chemical (ATC) classification system was used for classifying medications.

Results: Prevalence of polypharmacy was 10.4%, (95% CI: 9.75; 11.08) and it was higher among females (15.0%), older adults (age≥65 years) (16.0%), and individuals with more than two chronic conditions (31%). Being female, educated, married, and not having a low socio-economic class were independently associated with a higher likelihood of polypharmacy. The most prevalent medications among female participants were sex hormones and modulators of the genital system (58.4%), drugs for acid-related disorders (14.6%), and anti-anemic preparations (13.6%,). On the other hand, males were using acid-related disorders (14.6%), anti-inflammatory and anti-rheumatic products (7.8%), and beta-blocking agents (6.3%).

Conclusion: The prevalence of polypharmacy in our sample was relatively low, especially among males. Cardiovascular drugs, acid suppressants, hormonal contraceptives, and anti-anemic preparations are drug classes with the highest contribution to polypharmacy.