Impact of the COVID-19 pandemic on initiation of antihypertensive drugs in Sweden: an interrupted time series study

Objectives Antihypertensives reduce the risk of myocardial infarction and stroke. Restrictions during the COVID-19 pandemic limited access to healthcare, which may have had a negative impact on drug prescribing. This study aimed to assess the effect of the COVID-19 pandemic on the initiation of antihypertensive drugs.Design Interrupted time series study using a segmented linear regression model.Setting Swedish population assessed through linked national healthcare registers.Participants 720 300 new users of antihypertensives.Intervention March 2020, COVID-19 pandemic onset.Main outcomes measures The change in the initiation of antihypertensives expressed as monthly cumulative incidence, stratified by age and sex. Data on dispensed prescriptions of diuretics, beta-blockers, calcium channel blockers, ACE inhibitors (ACEi) and angiotensin receptor blockers were extracted from the Swedish Prescribed Drug Register, from March 2018 to November 2021. Initiation (new use) was defined as having no previous dispensations before March 2019. Monthly cumulative incidence in March 2019–November 2021 was calculated as the number of patients initiating each drug class in each month divided by the population.Results The start of the pandemic was associated with an immediate drop in the initiation of any antihypertensive, but no sustained effects were observed, as the incidence continued to increase in the postinterruption period by +0.02% each month in both sexes. The immediate drop was statistically significant for ACEi in both sexes and all antihypertensive classes except diuretics in patients >65 years. А significant postintervention trend change was observed for initiation of diuretics (+0.013% overall), driven mainly by a significant increase in patients >65 years. Similar findings were also observed for diuretics in females (+0.02%) and ACEi (+0.03%) in patients >65 years.Conclusions The pandemic had an immediate negative short-term effect, but we found no major long-term negative influence of the COVID-19 pandemic on initiation of any type of antihypertensive drugs.