Socioeconomic Status and the Use of Medicines in the Ontario Public Drug Program.

Residents of Ontario aged 65 years and older are covered by a provincially funded prescription drug program. The aim of this paper is to assess the extent of inequity in prescription drug use for people eligible for Ontario Drug Benefit coverage, and to explore the different possible explanations for inequities. The analyses draw on the Canadian Community Health Survey from 2005, which is linked to pharmacy and Ontario Health Insurance Plan claims data. We model the number of therapeutically different prescription drugs and the total expenditures on medications on a set of health, demographic, and socioeconomic indicators, and we calculate the concentration index of income-related inequality in medicine use. The results show that low-income individuals who have enrolled in the reduced cost-sharing program on average use more medications than those with higher income, even after adjusting for a comprehensive set of health and demographic variables. While Ontario's public drug program appears to have ensured access to medications for low-income seniors, the results of this study raise concerns about the potential inappropriateness of medication use and point to a gap in drug policy in Ontario. [ABSTRACT FROM AUTHOR]