Income-based drug coverage in British Columbia: the impact on access to medicines

In May 2003, the government of British Columbia adopted income-based pharmacare, replacing an age-based program. Stated policy goals included the maintenance or enhancement of access to necessary medicines. This study examines the policy impact on access to two widely used drugs for chronic risk factors (antihypertensives and statins).

Data on incident antihypertensive and statin prescriptions between 1997 and 2004 were extracted from PharmaNet. Incident antihypertensive users were those who filled a first prescription after residing in the province for at least two years prior to the initial prescription date. The number of patients who ceased to fill a contiguous series of prescriptions (within 120 days of one another) was used as a measure of apparent discontinuation or interruption of therapy. We used time series analysis to test for changes in incident use and discontinuation.

Between 1997 and 2004, 530,167 BC residents initiated therapy with an antihypertensive, and 264,904 BC residents initiated therapy with a statin. The 2003 policy change had no statistically significant impact on incident use of antihypertensives or statins, when stratified by age or income. Similarly, the 2003 policy did not change the rate of apparent discontinuations of therapy across age and income groups. However, a co-payment introduced in 2002 did increase end-of-year seasonality in apparent discontinuations in seniors--a finding that deserves further research.

The 2003 transition to income-based pharmacare in British Columbia did not result in significant changes in access to, or continuation of, prescriptions to treat two leading chronic risk factors.