Background: To curb the growing impact of drug shortages, Health Canada developed the Tiered Notification and Communication Framework which assigns shortages a corresponding tiered status. Tier-3 is assigned to shortages with the greatest potential impact on the healthcare system and drug supply. Each status has associated policy measures and frameworks indented to mitigate the shortage and curb its impact.
Objectives: The aim of this study was to examine drug utilization trends in response to Tier-3 shortages and to understand the impact of Tier-3 policies.
Methods: A time-series analysis of monthly dispensing data for Tier-3 drugs hydralazine, sarilumab, and medroxyprogesterone acetate, was conducted using IQVIA MIDAS data from January 2016 to December 2021. The shortage start dates for hydralazine, sarilumab, and medroxyprogesterone acetate were August 21, 2019, March 3, 2020 and July 6, 2021, respectively. The shortage impact following the start date was assessed with interventional ARIMA modelling and changes in utilization were quantified as 1-, 3-, and 6-month percent changes.
Results: Medroxyprogesterone acetate experienced a significant shift (p=0.0370) in utilization trends following its shortage, and the 1-, 3-, and 6-month percent changes were +14.9%, +6.8% and -3.1%, respectively. Hydralazine and sarilumab did not face a significant shift in utilization trends. The 1-, 3-, and 6-month percent changes for hydralazine were +15.5%, +10.2%, and +9.6%, respectively, and +25.2%, +45.1% and +39.2 for sarilumab.
Conclusions: These results indicate that although drugs assigned Tier-3 status still face shortages, these policies can potentially curb severe drops in drug utilization. However, there is little insight into the mechanisms behind these policy measures, and whether they are functioning as intended. These findings highlight the need for further research focused on understanding the impact of policies, and to determine which policy measures are most appropriate for combating specific challenges in drug supply.
