COVID-19 and the prevalence of drug shortages in Canada: a cross-sectional time-series analysis from April 2017 to April 2022

BACKGROUND: In March 2020, the Government of Canada introduced measures to reduce intensifying shortages of prescription drugs during the beginning of the COVID-19 pandemic. We sought to assess the extent to which a decline in drug shortages was observed in the months after this policy change. METHODS: Our data source was the Drug Shortages Canada Database, which reports shortages by drug product, including shortage start and duration. Using a cross-sectional design, we tracked shortage rates of drug products using a 30-day moving average from Apr. 15, 2017, to Apr. 1, 2022. We used autoregressive integrated moving average modelling with a ramp function to determine the significance of trend changes after policy implementation. RESULTS: We found that of the 13 329 drug products at risk for shortage, 44.7% (n = 5953) had at least 1 shortage event in the past 5 years. Average daily shortage prevalence rates rose from 901 in April 2017 to a peak of 2345 by April 2020. Significant declines (p = 0.02) ensued shortly thereafter, dropping to a rate of 1611 shortages by the end of the first year after policy implementation. However, we did not observe a significant reduction in shortage rates in the second year (p = 0.2), with rates plateauing below 1500 and then rising back above 1600 by the end of March 2022. INTERPRETATION: Drug shortages are common in Canada, including during the initial months of the COVID-19 pandemic. We observed substantial improvements after the implementation of the new measures, but gains appear to have plateaued. Continued vigilance is needed to sustain improvements.