The Associations of Prescription Drug Insurance and Cost-Sharing With Drug Use, Health Services Use, and Health: A Systematic Review of Canadian Studies.

Objectives: In Canada, public insurance for physician and hospital services, without cost-sharing, is provided to all residents. Outpatient prescription drug coverage, however, is provided through a patchwork system of public and private plans, often with substantial cost-sharing, which leaves many underinsured or uninsured.

Methods: We conducted a systematic review to examine the association of drug insurance and cost-sharing with drug use, health services use, and health in Canada. We searched 4 electronic databases, 2 grey literature databases, 5 specialty journals, and 2 working paper repositories. At least 2 reviewers independently screened articles for inclusion, extracted characteristics, and assessed risk of bias.

Results: The expansion of drug insurance was associated with increases in drug use, individuals who reported drug insurance generally reported higher drug use, and increases in and higher levels of drug cost-sharing were associated with lower drug use. Although a number of studies found statistically significant associations between drug insurance or cost-sharing and health services use, the magnitudes of these associations were generally fairly small. Among 5 studies that examined the association of drug insurance and cost-sharing with health outcomes, 1 found a statistically significant and clinically meaningful association. We did not find that socioeconomic status or sex were effect modifiers; there was some evidence that health modified the association between drug insurance and cost-sharing and drug use.

Conclusions: Increased cost-sharing is likely to reduce drug use. Universal pharmacare without cost-sharing may reduce inequities because it would likely increase drug use among lower-income populations relative to higher-income populations.