Work ability trajectories and sick leave in individuals with post COVID-19 condition: 3-year follow-up of a population-based cohort.

Background: Data on the longer-term impact of post COVID-19 condition (PCC) on work-related functioning is limited, despite evidence on the persistence of PCC for years after infection. This study aimed to describe changes in work ability and sick leave associated with PCC up to three years post-infection. Methods: We used data from 667 working-age individuals within a prospective population-based cohort following individuals infected with SARS-CoV-2 between August 2020 and January 2021. PCC was determined at 12 months and work ability was assessed biannually. The impact of SARS-CoV-2 on participants' physical and mental work performance and COVID-19 related sick leave were assessed at three years. Findings: Participants with protracted COVID-19 related symptoms at 12 months after infection reported persistently lower work ability scores than those without symptoms, with no evidence of a difference in change over time (-0.12 points per year, 95% CI -0.29 to 0.07). Compared to recovered individuals, work ability scores among those with moderate health impairment improved by +0.72 points per year (95% CI -0.04 to 1.46), while trends were similar among those with mild or severe impairment. A higher proportion of participants with PCC reported worsening in physical and mental performance at work than those without PCC. Among those with PCC, 11.5% (9/78) reported taking COVID-19 related sick leave for one month or more, in contrast to 4.0% (13/327) among those without PCC. Interpretation: The study highlights the prolonged impact of PCC on work-related functioning and underscores the need for targeted occupational, clinical and social measures for those affected. Funding: Federal Office of Public Health, Department of Health of the Canton of Zurich, University of Zurich Foundation, Switzerland; Horizon Europe.