Return to Work Following Medical Rehabilitation for Musculoskeletal Disorders in Times of the COVID-19 Pandemic: A Retrospective Cohort Study.

Objective: To describe and explain the impact of the COVID-19 pandemic and its related measures on return-to-work (RTW) outcomes following multimodal medical rehabilitation for musculoskeletal disorders.

Design: Retrospective cohort study SETTING: Three cohorts: reference (rehabilitation and RTW pre-pandemic), pandemic 1 (rehabilitation pre-pandemic, RTW during pandemic), pandemic 2 (rehabilitation and RTW during pandemic).

Participants: Individuals who underwent multimodal medical rehabilitation for musculoskeletal disorders through the German Pension Insurance system between January 2018 and December 2021 (N = 688,127).

Main outcome measure: A successful and stable RTW was operationalized as having employment subject to social insurance contributions in the ninth to twelfth month following rehabilitation.

Results: Descriptive analysis revealed a RTW rate of 67.2% in the reference cohort, a slight decline in pandemic cohort 1 (66.3%) and a more pronounced decrease in pandemic cohort 2 (63.1%). In contrast, average marginal predictions from a logistic model including various covariates showed that both pandemic cohorts (63.8%, 64.4%) exhibited similarly reduced predicted probabilities of RTW compared to the reference cohort (66.5%). Individuals with sick leave durations exceeding 6 months, compared to those with shorter sick leaves, were more negatively affected by pandemic cohort 1; however, this effect recovered in pandemic cohort 2. The interaction between cohort and income did not show any amplifying effect of the pandemic.

Conclusion: The logistic model revealed no differences in predicted probabilities of RTW between pandemic cohort 2 and pandemic cohort 1, suggesting that orthopedic rehabilitation remained robust in maintaining RTW outcomes despite pandemic-related challenges. The findings offer mixed evidence regarding the question whether the pandemic amplified pre-existing barriers to RTW.