Beneficiary cost sharing under Canadian provincial prescription drug benefit programs: history and assessment.

INTRODUCTION: Federal legislation outlined in the Medical Care Act of 1966 and the Canada Health Act of 1984 stipulates that Canadian provincial governments are to administer insurance programs for "medically necessary" services provided by hospitals and physicians. The legislation did not mandate provincial government coverage for prescription drugs taken outside of the hospital. Each province has, however, provided coverage to senior citizens and social assistance recipients; some provinces have introduced drug coverage for the general public. METHODS: The present paper reviews the history of the provincial drug insurance programs for these three beneficiary groups (seniors, social assistance recipients and the general public), from the inception dates of the programs to October 31, 2000. Attention is given to eligibility conditions and amounts of beneficiary cost sharing. RESULTS: A review of the history of the provincial drug programs reveals a significant variation in the amounts of patient cost sharing between and within programs and over time. In addition, starting in the early 1990s, there was a trend in most provinces to increase the generosity of coverage for those with large drug expenses relative to income, irrespective of beneficiary age, typically at the expense of reduced coverage for senior citizens. Some implications of this trend are drawn in light of evidence of the deleterious effects of cost sharing targeted at senior citizens.