To assess the distribution and spending by cost-effectiveness category among those drugs with the highest public spending levels in Canada.

Repeated cross-sectional study.

The Canadian provinces of Manitoba, Ontario, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland.

Cost-effectiveness assessments by the Canadian Agency for Drugs and Technologies in Health (CADTH) for top-100 brand-name outpatient drugs by gross public plan spending in any year between 2015 and 2021 in Canada Institute for Health Information’s National Prescription Drug Utilization Information System data. Gross public plan spending by cost-effectiveness category.

From 2015 to 2021, 152 brand-name drugs occupied a top-100 rank and were included in the analysis. Of those, 117 had been assessed by CADTH. During the 7-year period, there was an increase in both top-100 drugs with cost-effective (from 18 to 24) and cost-ineffective (from 29 to 41) assessments, while drugs not assessed or with an unclear assessment declined (from 31 to 19 and from 22 to 16, respectively). As a share of spending on top-100 drugs with an assessment, spending on cost-effective drugs was mostly stable at 40%–46% from 2015 to 2021, while spending on cost-ineffective drugs increased from 30% to 45%.

A large and growing share of public drug spending has been allocated to cost-ineffective drugs in Canada. Dedicating large budgets to such treatments prevents spending with greater health impact elsewhere in the healthcare system and could restrain the capacity to pay for groundbreaking pharmaceutical innovation in the future.

To assess the impact of the COVID-19 pandemic on prescription drug use and costs.

Interrupted time series analysis of comprehensive administrative health data linkages in British Columbia, Canada, from 1 January 2018 to 28 March 2021.

Retrospective population-based analysis of all prescription drugs dispensed in community pharmacies and outpatient hospital pharmacies and irrespective of the drug insurance payer.

Between 4.30 and 4.37 million individuals (52% women) actively registered with the publicly funded medical services plan.

COVID-19 pandemic and associated mitigation measures.

Weekly dispensing rates and costs, both overall and stratified by therapeutic groups and pharmacological subgroups, before and after the declaration of the public health emergency related to the COVID-19 pandemic. Relative changes in post-COVID-19 outcomes were expressed as ratios of observed to expected rates.

After the onset of the pandemic and subsequent COVID-19 mitigation measures, overall medication dispensing rates dropped by 2.4% (p

The COVID-19 pandemic impact on prescription drug dispensing was heterogeneous across medication subgroups. As data become available, dispensing trends in nervous system agents, antibiotics and antivirals warrant further monitoring and investigation.