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

Objective: To describe and explain the effect of the coronavirus disease 2019 pandemic and its related measures on return to work (RTW) outcomes after multimodal medical rehabilitation for musculoskeletal disorders.

Design: Retrospective cohort study.

Setting: Three cohorts: reference (rehabilitation and RTW prepandemic), pandemic 1 (rehabilitation prepandemic, RTW during pandemic), and 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).

Interventions: Not applicable.

Main outcome measures: A successful and stable RTW was operationalized as having employment subject to social insurance contributions from 9 to 12 months after rehabilitation.

Results: Descriptive analysis revealed an 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% and 64.4%) exhibited similarly reduced predicted probabilities of RTW compared with the reference cohort (66.5%). Individuals with sick leave durations exceeding 6 months, compared with 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.

Conclusions: 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 of whether the pandemic amplified preexisting barriers to RTW.