The Impact of reference pricing on prescribing patterns, costs, and health services utilization of proton pump inhibitors: A quasi-experimental study in British Columbia, Canada

Introduction: The Reference Drug Program (RDP) was established to steer patients toward equally safe and costeffective medication under British Columbia's public drug coverage. Each RDP class covers at least one reference drug, and non-reference drugs are reimbursed up to the cost of the reference drug. In 2016, the RDP updated to include proton pump inhibitors (PPIs). This study evaluated the impact on drug expenditures, prescription patterns, and health services utilization. Methods: We identified a cohort of individuals covered by Fair Pharmacare who used PPIs, and a control group of H2 Blockers users. We used interrupted time series analysis on administrative data from June 2014 to December 2019 on the following outcomes: new users, day supply, expenditures, drug costs, reference drug use, and physician visits and costs. Results: The RDP had little impact on overall PPI use patterns. We did not observe any changes in reference drug uptake, new users, physician visits, cost-savings, or significant changes to days supplied post-policy. Cost expenditure results were likely biased due to co-occurring changes to drug prices. Conclusion: Inclusion of PPIs to the RDP saw no cost-savings for the provincial drug program and had little impact on prescribing patterns. Overall, our findings are consistent with existing evidence that the RDP is safe for similar therapeutic alternatives, but the impact on PPI costs remains unclear.