Capturing the Active Ingredients of Multicomponent Participatory Organizational Stress Interventions Using an Adapted...

Adapted study designs use process evaluation to incorporate a measure of intervention exposure and create an artificial control and intervention groups. Taking into account exposure levels to interventions combines process and outcome evaluation and strengthens the design of the study when exposure levels cannot be controlled. This study includes longitudinal data (two assessments) with added process measures at time 2 gathered from three complex participatory intervention projects in Canada in a hospital and a university. Structural equation modelling was used to explore the specific working mechanisms of particular interventions on stress outcomes. Results showed that higher exposure to interventions aiming to modify tasks and working conditions reduced demands and improved social support, but not job control, which in turn, reduced psychological distress. Exposure to interventions aiming to improve relationships was not related to psychosocial risks. Most studies cannot explain how interventions produce their effects on outcomes, especially when there are multiple concurrent interventions delivered in several contexts. This study advances knowledge on process evaluation by using an adapted study design to capture the active ingredients of multicomponent interventions and suggesting some mechanisms by which the interventions produce their effects on stress outcomes. It provides an illustration of how to conduct process evaluation and relate exposure levels to observed outcomes. Copyright © 2016 John Wiley & Sons, Ltd.