Background: Polypharmacy can negatively affect the life of type 2 diabetes (T2DM) patients. There is little evidence on the associated factors of, and patterns of polypharmacy among T2DM patients in developing regions. The aim of this study is to determine the population-based prevalence of polypharmacy, its associated factors, and pattern in southern Iran.

Methods: We used baseline data from the Pars Cohort Study (PCS). Age-standardized prevalence of polypharmacy and its 95% confidence interval (CI) were estimated. Association of polypharmacy with demographic and socio-economic factors, anthropometric measures, serum biomarkers, physical activity, cigarette and tobacco smoking, and multimorbidity was assessed by applying multivariable Poisson modeling. Prevalence ratio (PR) and its CI were estimated. The Anatomical Therapeutic Chemical (ATC) classification system was used for drug classification.

Results: Totally, 874 previously diagnosed T2DM patients with a mean age of 56.3±9.2 participated in the study. The estimated age-standardized prevalence for men and women was 17.2% (CI: 12.0-22.0) and 34.1% (CI: 33.2-39.4), respectively. The prevalence of hypertension, hyperlipidemia and cardiovascular disorders among the study population was 39%, 58% and 20%, respectively. Having more than four comorbidities (PR, 3.90; CI, 2.39-6.34), central obesity (PR, 2.66; CI, 1.03-6.84), and female gender (PR, 1.49; CI, 1.14-1.97) were associated with polypharmacy. Also, 56.0% of patients and 23.0% of elder patients (>59 years old) reported using anti-diabetic agents.

Conclusion: Polypharmacy was low among T2DM patients. More than 75% of the elder population were not on anti-diabetic medications. Polypharmacy was higher among patients with multiple comorbidities, central obesity, lower physical activity, lower socio-economic status, younger age at diagnosis, and longer duration of T2DM.