Objective Organisational change may negatively affect employees’ health and social capital. This study examined the magnitude of mediated effects from organisational change through social capital on long-term sickness absence (LSA) among public hospital workers.

Method In March 2014, 26.209 workers employed through January-December 2013 in the Capital Region of Denmark received a work-environment survey assessing social capital (84% responded). Social capital, measured using 8 self-reported items (collaboration, trust, and organisational justice) ranging 0-5/0-7 (low-high), was aggregated on work-unit level and categorised into quartiles. Organisational change (e.g., merger, layoff(s), and relocation) during July-December 2013 were recorded via surveys sent to all managers (58% responded). Monthly sickness-absence data of 2014 were obtained from regional salary registries (LSA:>28 days). Mediation was assessed using natural effects models nested on January-September 2014 and estimated the natural direct, indirect, and total effects from organisational change on LSA via social capital adjusting for age, gender, work-unit size, occupation, child- and health-proxies.

Results Exposure to merger or layoff(s) yielded significant adverse direct effects (OR 1.33, 95% CI 1.12–1.58 and OR 1.15, 95% CI 1.01–1.30, respectively) and adverse indirect effects via social capital (OR 1.04, 95% CI 1.02–1.06 and OR 1.04, 95% CI 1.03–1.05, respectively) on LSA (total effects: OR 1.38, 95% CI 1.17–1.64 and OR 1.19, 95% CI 1.05–1.36, respectively).

Surprisingly, exposure to relocation showed a protective direct effect (OR 0.73, 95% CI 0.58–0.91), but a significant adverse indirect effect (OR 1.01, 95% CI 1.00–1.03) on LSA (total effect: OR 0.74, 95% CI 0.52–0.92).

Conclusion Social capital potentially mediates adverse effects from organisational change on LSA.