Functional impact of long Covid on work performance and return to work: a cross-sectional study

To evaluate the association between long Covid and socioeconomic, clinical, healthcare, and functional factors with reduced work performance and difficulty returning to work.

A cross-sectional study of individuals in São Paulo aged ≥ 18 years with long Covid (77.8%), with data collected between April 2023 and June 2024. A systematic random sample of severe and mild Covid-19 cases from March 2020 to January 2022. The severity of Covid-19 was classified according to the U.S. Centers for Disease Control and Prevention (CDC) guidelines. Prevalences were assessed, and a Poisson test was performed to examine the association between reduced work performance and difficulty returning to work and sociodemographic, clinical, healthcare-related, and functional factors considered significant (p ≤ 0.05). Among the participants, 43.9% experienced reduced work performance, and 22.2% had difficulty returning to work. Long Covid is defined as having two or more symptoms that develop and persist for more than four weeks after Covid-19, cannot be explained by an alternative diagnosis, and are assessed using a Likert scale for the intensity of self-reported symptoms (0-10). Participants' functional status was assessed using scales for basic activities (Katz), instrumental activities (Lawton), functional limitations (WHO-DAS), and sarcopenia (SARC-F).

Poorer work performance was associated with advanced age (PR = 2.20; 95%CI 1.27-3.80), as well as being the primary provider (PR = 1.55; 95%CI 1.05-2.29), and having moderate (OR = 2.99; 95%CI 1.60-5.58) or severe (OR = 4.88; 95%CI 2.59-9.19) functional impairment. For difficulty returning to work, the main association observed was severe functional impairment (OR = 4.33; 95%CI 1.58-11.80).

It is noteworthy that advanced age and, particularly, severe functional impairment were significantly associated with poorer performance and difficulty returning to work in the studied population with long Covid.