Change in healthcare utilization before and after COVID-19 using data from 1.5 million individuals

Post-infectious sequelae can increase burden on healthcare systems. We aimed to assess the long-term effect of COVID-19 on healthcare utilization across all levels of care.

In this register-based cohort study, we included all adult (≥18 years) residents in Sweden's two largest counties with a registered COVID-19 index date between 31 January 2020 and 9 February 2022. Each exposed individual was matched 1:1 to a control without registered COVID-19 on index date based on gender, birth year, vaccination status and the change in number of healthcare contacts between 2018 and 2019. We counted the number of healthcare contacts across all levels of care during the pre-index (13-1 months) and post-index (4-15 months) full-year periods. A difference-in-difference (DID) analysis was used to assess changes in the number of healthcare contacts and specific diagnoses, between each individual's pre- and post-periods, as well as comparing individuals with and without COVID-19.

The study included 753,905 matched pairs, comprising 1,415,432 unique individuals. Trends in healthcare contacts were parallel between the matched groups prior to the index date. The DID analysis revealed a mean increase of 0.33 (95%CI 0.30-0.36) healthcare contacts following COVID-19, mainly observed from a smaller proportion of the population (5%) and by contacts with primary healthcare. The largest diagnosis-specific difference was observed for reactions to severe stress (0.02, 0.01-0.03). The estimate varied across gender, acute COVID-19 severity, virus variant period and vaccination status.

This study demonstrates increased healthcare utilization after COVID-19 in a smaller proportion of the population.