Purpose of Study
The purpose of this study was to examine the prevailing idea that provincial drug formularies vary widely.
The authors performed analysis of interprovincial formulary agreement by applying national expenditure weights to drugs across therapeutic categories.
Key Overarching Message
Results suggest that there is a high level of interprovincial agreement on coverage of high-volume medicines. This shows that Canada has an implicit national formulary that may provide national standards for drug coverage, and allow Canada to consolidate purchasing power to save drug costs.
Provincial formularies listed between 55% and 73% of the 796 drugs analyzed. When formulary listings were weighted by national retail sales, the measure of formulary coverage exceeded 86% in all provinces studied. Conventional inter-rater reliability scores indicated that provincial coverage agreement was low to moderate; however, drugs listed on provincial formularies studied accounted for 77% of total retail spending in Canada. When analyzed by therapeutic category, the extent of coverage offered was relatively consistent across provinces in all but three leading categories: anti-migraine drugs, anti-dementia drugs and sedatives.