The Impact of Private Insurance Coverage on Prescription Drug Use in Ontario, Canada.

Canadians obtain prescription drug coverage through a patchwork of public insurance, private benefit plans and out-of-pocket payments. Prior evidence suggests that insurance coverage, in general, leads to higher utilization rates of essential medicines; it is unclear whether individuals with private insurance have better access to medicines. Using data from the 2008 Canadian Community Health Survey, we identified cohorts from Ontario who reported having been diagnosed by a physician with asthma, high blood pressure or diabetes. Using propensity score stratification techniques, we compared drug utilization of individuals holding private insurance with that of individuals holding either public insurance (for those aged over 65 years) or no insurance (aged under 65 years). In five out of six comparisons, individuals with private insurance were more likely to take prescribed drugs than those without. Raw differences in the percentage of patients taking medicines ranged from 0.1 to 8.1%. Ontarians with chronic conditions holding private drug insurance are more likely to use prescription drugs than those who do not. Whether these inequities result in health outcome differences remains unknown.