Explanation of Socio-economic Inequality in Medicine Use: A Cross-sectional Analysis from Iran

Background: Despite the favorable progress in the production of medicines, there is no significant access to these important health inputs among different socio-economic groups. Objectives: This study aimed to measure and explain socio-economic inequality in prescribed and non-prescribed medicine use in Iran. Methods: Data were obtained from a recent household survey on health services in Iran conducted in 2016. The Erreygers concentration index (ECI) was used to measure socio-economic inequality in the use of prescribed and non-prescribed medicines. In addition, Decomposition analysis was conducted to explain socio-economic inequality. Results: The ECI revealed pro-rich socio-economic inequality in prescribed medicine use (ECI = 0.067, SE = 0.010), indicating that prescribed medicine use was concentrated on the better-offs. On the other hand, this index showed pro-poor inequality in non-prescribed medicine use (ECI = -0.064, SE = 0.009). Decomposition analysis showed that economic status and place of residence were the main determinants of socio-economic inequality in prescribing medicines. These factors and the number of health care needs explained the majority of socio-economic inequality in non-prescribed medicine use. Conclusions: Despite previous positive beliefs, we found remarkable socio-economic inequality in the use of medicines in Iran. Facilitating access to pharmaceutical services for disadvantaged households and rural residents and promoting of national essential medicines list could be recommended against socio-economic inequality in the pharmaceutical market of Iran.