Trends in medication use at the onset of and during the COVID-19 pandemic in the Republic of Ireland: An interrupted time series study

Abstract

The COVID-19 pandemic had a substantial impact on healthcare delivery, particularly in general practice. This study aimed to evaluate how dispensing of medications in primary care in Ireland changed following the COVID-19 pandemic's onset compared to expected trends. This interrupted time series study used data on medications prescribed in general practice 2016–2022 to patient eligible for state health cover, approximately one third of the population. Dispensing volumes for all therapeutic subgroups (ATC2 codes) and commonly dispensed medications were summarized. Pre-pandemic data were used to forecast expected trends (with 99% prediction intervals) using the Holt-Winters method, and these were compared to observed dispensing from March 2020 onwards. Many (31/77) therapeutic subgroups had dispensing significantly different from forecast in March 2020. Drugs for obstructive airway disease had the largest difference, with dispensing 26.2% (99%CI 19.5%–33.6%) higher than forecasted. Only two subgroups were significantly lower than forecasted, other gynaecologicals (17.7% lower, 99%CI 6.3%–26.6%) and dressings (11.6%, 99%CI 9.4%–41.6%). Dispensing of amoxicillin products and oral prednisolone were lower than forecasted in the months following the pandemic's onset, particularly during winter 2020/2021. There was a spike in dispensing for many long-term medications in March 2020, while pandemic restrictions likely contributed to reductions for other medications.