Realist evaluation of a CBT-based stress management intervention for Danish patients on sick leave due to work-related stress: A study protocol

Cognitive behavioural therapy (CBT) is the most widely used stress management intervention for work-related stress, however the effect on return to work is unclear. Further, there is a lack of knowledge about the mechanisms and contexts that make CBT interventions work (or not). This project aims to use a realist evaluation approach to explore the outcomes of a stress management intervention at a Danish Occupational Health Clinic and to understand if, how and why it works (mechanisms), for whom and in what circumstances (contexts). Firstly, the initial programme theory (IPT) will be elicited. Secondly, the IPT will be tested using a mix of methods. The primary outcome of the intervention; return to work, will be assessed in a quasi-experimental study using register data on sick-leave compensation. In a cohort study explanatory variables from patient surveys and national registries associated with outcomes will be explored. Finally, realist theory driven interviews with patients will explore what works, for whom in what context. The data will be analysed using a realist logic, and synthesized to refine, refute, or confirm the IPT. The refined programme theory will offer insights about what patient groups benefit from the intervention (if any), under what circumstances, and why. • The effect of cognitive behavioural therapy (CBT) on return to work remains unclear and understudied • Realist evaluation explores if, how, for whom and in which circumstances interventions ‘work’ • The protocol details a theory-driven mixed methods quasi experimental evaluation • Findings aim to refine theoretical understanding and inform delivery of CBT interventions