Quality of leadership and self-rated health: the moderating role of 'Effort-Reward Imbalance': a longitudinal perspective.

Objective: Longitudinal studies on the influence of leadership behavior on employees' self-rated health are scarce. As a result, potential mechanisms describing the impact of leadership behavior on health have not been adequately investigated so far. The present study accounts for the influence of leadership behavior on self-rated health within the framework of the Effort-Reward Imbalance model.

Methods: The study was conducted on the basis of a cohort which comprised a random sample of healthcare workers from ten different hospitals and one elderly nursing home in Germany. A 2-level repeated measurement model with random intercept and slopes was modeled, since it was aimed to account for individual as well as intra-individual variation of subjective health across three time points over 36 months. Beside 'Effort-Reward Imbalance' and 'Quality of Leadership' from the Copenhagen Psychosocial Questionnaire, physical and mental health was assessed by German version of the SF12 multipurpose short-form measure of health status.

Results: 'Effort-Reward Imbalance' and a lack in 'Quality of Leadership' negatively affect self-rated physical health. No effect was found for self-rated mental health. Effort-Reward Imbalance significantly moderates the effect of 'Quality of Leadership' on self-rated physical health.

Conclusion: The findings, and the interaction effects in particular, suggest that leadership behavior moderated by factors such as appreciation and support, influences self-rated physical health. The study therefore provides an interpretation for leadership behavior and its influence on employees' self-rated health within the 'Effort-Reward Imbalance' model.