AIMS: Evidence for the effectiveness of return-to-work (RTW) interventions aimed at sickness absence beneficiaries with mental health problems (MHPs) is still relatively sparse and mostly inconclusive. This may in part reflect the varying settings and inconsistent implementations associated with the interventions. The aim of this paper is to identify barriers and facilitators for the implementation of a coordinated and tailored RTW-intervention implemented at three different sites.

METHODS: We used qualitative and quantitative data to assess the implementation according to process evaluation guidelines. Data sources were individual and group interviews, observations, national registers, and documents used in the intervention.

RESULTS: The quality of the implementation varied greatly across the three settings. Barriers included lack of skills to assess MHPs according to the inclusion criteria, different interpretations of sickness absence legislation among stakeholders, competing rehabilitation alternatives, and lack of managerial support for the intervention. An important facilitator was the motivation and availability of resources to solve disagreements through extensive communication.

CONCLUSIONS: The different settings presented various barriers and facilitators, which resulted in different versions of the intervention. A higher degree of user involvement in the design and development phase is likely to improve the implementation quality of future interventions.