Impact of the COVID-19 pandemic on prescription drug use and costs in British Columbia: a retrospective interrupted time series study

Abstract

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

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

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

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

Intervention: COVID-19 pandemic and associated mitigation measures.

Main outcome 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.

Results: After the onset of the pandemic and subsequent COVID-19 mitigation measures, overall medication dispensing rates dropped by 2.4% (p<0.01), followed by a sustained weekly increase to return to predicted levels by the end of January 2021. We observed abrupt level decreases in antibacterials (30.3%, p<0.01) and antivirals (22.4%, p<0.01) that remained below counterfactuals over the first year of the pandemic. In contrast, there was a week-to-week trend increase in nervous system drugs, yielding an overall increase of 7.3% (p<0.01). No trend changes in the dispensing of respiratory system agents, ACE inhibitors, antidiabetic drugs and antidepressants were detected.

Conclusion: 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.

Keywords: COVID-19; EPIDEMIOLOGY; Health policy; THERAPEUTICS.