Statistical analysis
overcommitment
REGRESSION, REGRESSION
The descriptive statistics of the sample and the correlation matrix are provided in Table Correlations at baseline, proportions (%) of selected variables and sample sizes of the intervention (WAI-P: physical work ability, WAI-M: mental work ability, NA: not availableIn order to ease the interpretation of the results obtained in the regression analysis, in particular for the interaction model, the marginal effects of efforts and low rewards on physical and mental work ability by levels of overcommitment are depicted in Fig. Finally, the regression models revealed that healthcare workers who did not experience ward transfers reported higher work ability levels than transferred workers. However, the analyses did not suggest that the COVID-19 disruptions had a larger impact on work ability. In fact, there were only about 13% ward transfers during the intervention period, with COVID-19 related transfers or changes accounting for only 30% of ward transfers. In total, only about 7% of the survey participants were affected by some COVID-19 related changes during the intervention. Hence, the results of the regression models concerning ward transfers indicate that transfers in themselves posed increased demands on transferred workers and, thus, may have contributed to lower work ability, especially for its mental component. On the other hand, while the analysis indicated that physical, but not mental work ability, decreases with increasing age, the role of sex was less consistent and seemed to be fully mediated by the psychosocial workload. This can observed by taking into consideration that sex did not contribute to the proportion of explained variance of the work ability components in models 2 and 3, in which the ERI scales are taken into account. Hence, the observed sex-specific differences regarding work ability are likely due to differences in the perception of the psychosocial workload as measured by the ERI scales.Generalised linear regression models. Dependent variables: physical and mental work ability, WAI-P and WAI-M, respectively. Regression coefficients and 95% confidence intervals in brackets. 
Estimated marginal effects of efforts, low rewards and overcommitment on physical and mental ability by treatment. Estimates obtained from regression model 3