(100) Drug Shortages in the U.S. and Canada Prior to and During the COVID-19 Pandemic: A Multi-National, Cross-Sectional Study

Background: Drug shortages are a persistent global issue and are associated with treatment delays or omission, increased spending, and adverse health outcomes. Both the U.S. and Canada have experienced increases in supply chain issues, including during COVID-19. However, it is unknown what proportion of issues are associated with subsequent shortages.

Objectives: To quantify the proportion of supply chain issues in Canada and the U.S. which were associated with subsequent drug shortages. To assess differences in Canada vs. the U.S. and by pandemic period (pre- vs. post-March 2020).

Methods: We conducted a longitudinal cross-sectional study of prescription drugs in IQVIA’s MIDAS database. We restricted sampling to drugs with ≥1 supply chain issue report within 180 days in both countries. Our primary outcome was shortage within 12 months, defined as a decrease in purchased units ≥33%. We compared overall shortage hazards in Canada vs. the U.S. using unadjusted Kaplan-Meier curves and Cox models adjusted for drug formulation, unit-price, number of alternatives, years since market availability, generic availability, and WHO essential medicine status. Given known differences in reporting, we allowed for differing baseline hazards for recalls and discontinuations (combined) versus all other non-recall, non-discontinuation reports.

Results: There were 1,198 drugs purchased in both the U.S. and Canada. Of these, 156 had 1 concurrent report and 25 had two or more, for a sample size of 210 reports (15.1%). 106 (50.0%) were recalls or discontinuations. Among non-recalls/non-discontinuations, 45.2% were associated with shortages in the U.S. vs. 29.8% in Canada (HR, Canada vs. U.S.: 0.57, 95% CI: 0.39, 0.85). This finding was consistent pre-and post-March 2020 (HRs: 0.51, 95% CI: 0.32, 0.79 and 0.39, 95% CI: 0.15, 1.0). Recalls/discontinuations (combined) were marginally more likely to go on shortage in Canada (25.5%) vs. the U.S. (18.95%), HR: 1.71, 95% CI: 1.01, 2.93. However, this difference was no longer significant when stratified by COVID-19 period (pre-March-2020 HR: 1.5, 95% CI: 0.83, 2.78 and post-March-2020 HR: 1.2, 95% CI: 0.48, 2.9).

Conclusions: In this comparative study between the U.S. and Canada, one in seven drugs experienced a supply chain issue in both countries. Non-recalls/non-discontinuations had consistently lower hazards of subsequent shortages in Canada. Recalls and discontinuations were less likely to be associated with shortages in both countries; these often-voluntary reports may have limited impact on supply due to forward planning. Pro-active policy responses in Canada may explain the observed lower risk of shortages after non-recall/non-discontinuation reports.