Abstract
OBJECTIVE: To describe persistent symptoms after a work-related COVID-19 infection in health and welfare workers and the identification of predictors of these symptoms. METHODS: This short report summarises updated results on a bidirectional cohort study of employees in the health and welfare services who had reported a work-related SARS-CoV-2 infection in 2020. Participants were interviewed for the fourth time (T4) in April 2023 using a paper-and-pencil questionnaire. In this extended follow-up study (total prospective follow-up time: 26 months, maximum observation time 32 months), questions were asked about the type and severity of persistent symptoms. Kaplan-Meier curves were used to visualize cumulative survival rates, and Cox regression was used to identify predictors. RESULTS: Of the 2,053 participants in the baseline study (response rate: 47%), 1,075 people took part in the 4(th) survey (follow-up rate: 52%); the analysis sample for the longitudinal study comprised 1,809 participants. The most frequently reported persistent symptoms at T4 were fatigue (61%), concentration or memory problems (55%) and shortness of breath (49%). After 12 weeks, the cumulative survival rate was 76.3%, after 12 months 69.3%, and after 32 months 60.0%. Female gender was a statistically significant risk factor for a longer recovery time (Hazard Ratio [HR]: 0.8, 95% CI: 0.63-0.93, p=0.007) as was older age (HR ≥50 years 0.6, 95% CI: 0.51-0.76, p<0.001). Participants with one pre-existing condition had a 20% statistically significant increased risk (HR: 0.8, 95% CI: 0.66-0.95, p= 0.010), subjects with two pre-existing conditions a HR of 0.6 (95% CI: 0.46-0.75, p<0.001) and those with ≥3 pre-existing conditions had a HR of 0.3 (95%-CI: 0.23-0.48, p<0.001). Risk increases were also observed for the number of severe acute symptoms: the more symptoms, the greater the increase in risk. Individuals with medical activity (physicians) were 50% less likely to have a longer time to recovery compared to all other occupational groups (HR: 1.5, 95%-CI: 1.21-1.89, p<0.001). CONCLUSION: Minimal further recovery was observed in this cohort of insured persons after a 26-month prospective follow-up. Identified risk factors for persistent symptoms, i.e. female gender, older age, severe acute symptoms, and pre-existing illnesses, define a high-risk group of individuals, who should receive sufficient attention in the early phase of their COVID-19 disease and receive appropriate therapy to minimize the risk of post-COVID-19 syndrome.