Effort-reward-imbalance, burnout, and physical pain mediate the relationship between overcommitment and depression in German Emergency Medical Technicians

Background: Overcommitment (OC) is highly prevalent in health care employees, and may predict depression symptoms. The literature suggests that the relationship between OC and depression is mediated by Effort-Reward-Imbalance (ERI), burnout and physical pain. This study tested a two-step mediation effect between OC and depression by ERI in a first, and burnout and physical pain in a second step using a cohort of German Emergency Medical Technicians (EMTs). Methods: A cross-sectional study was carried out on a volunteer sample of 303 EMTs in Germany. OC and ERI were assessed using the ERI questionnaire, burnout with the Maslach Burnout Inventory, physical pain with the Short Form 36, and depression with the BDI-II. The relationship between these variables was tested using a mediation analysis. Results: We found a partial mediation effect between OC and depression via ERI, burnout (emotional exhaustion, personal accomplishment) and physical pain. The mediation effect of emotional exhaustion is significantly higher than those of depersonalization and physical pain. Conclusions: The partial mediation effect suggests the validity of our model assumptions, but also indicates direct relationships between variables (i.e. OC, ERI and depression). The identification of emotional exhaustion as key mediator implies that prevention and intervention approaches in EMTs should be based on this indicator.