Association of individual and community-level socioeconomic status and education with medication use: a multilevel analysis in the PERSIAN cohort.

Background: Socioeconomic status (SES) and education influence medication use, but their effects at both individual and community levels remain poorly understood. This study investigates the association between medication count and polypharmacy with SES and education at both levels.

Methods: We used data from the Prospective Epidemiological Research Studies in IrAN (PERSIAN), comprising 163,770 individuals aged 35-70 from 18 sites in Iran. Individual SES was evaluated using asset analysis, while community SES was determined based on the prevalence of low SES individuals in each site. Individual education level was dichotomized into having at least 5 years of schooling or not, while community education level was determined by the frequency of individuals with high education level in each site. Multi-level Poisson regressions, were conducted to explore the association between these variables and medication count in this cross-sectional study.

Results: Approximately 45% of participants used at least one medication, with an average of 1.32 medications per person. Polypharmacy was observed in 8.85% of the population. Higher individual SES was associated with a slightly increased medication count (PR 1.05; 95% CI: 1.02-1.08) and a modest increase in polypharmacy risk (PR 1.08; 95% CI: 1.03-1.14). Residing in middle-SES communities was linked to lower medication use (PR 0.88; 95% CI: 0.85-0.91) but was not significantly associated with polypharmacy. Higher individual education was associated with reduced medication count (PR 0.92; 95% CI: 0.88-0.96) and a lower likelihood of polypharmacy (PR 0.85; 95% CI: 0.79-0.91). However, living in highly educated communities was associated with increased medication count (PR 1.70; 95% CI: 1.62-1.78) and a higher risk of polypharmacy (PR 1.81; 95% CI: 1.16-2.81). The models were adjusted for age, gender, residence, ethnicity, marital status, body mass index, physical activity level, smoking status, opium use, hookah use, and alcohol consumption.

Conclusion: Higher education was associated with lower medication use, whereas living in more educated communities was linked to higher usage. Although the association between individual SES and medication use was relatively weak, residing in middle-SES communities was associated with lower medication usage. These findings show the importance of addressing community-level factors in health research and policymaking.