Purpose: Effort-reward imbalance (ERI) is a well-tested work-related stress model with three components, the two extrinsic components "efforts" and "rewards" and the one intrinsic component "overcommitment". While an imbalance between "efforts" and "rewards" leads to strain reactions, "work-related overcommitment" (OC) has been described as a personal characteristic with a set of attitudes, behaviours, and emotions reflecting excessive striving combined with a strong desire for approval. However, the question whether OC is a personality trait or a response pattern sensitive to changes in the work context (state) is still open.
Methods: 2940 Swedish industrial employees were included in this longitudinal analysis of the WOLF-Norrland data over 5 years. A change of OC index or its subscales were regressed against a change of freedom of choice at work, extra work, and ERI adjusted for age, sex, and education.
Results: While OC was insensitive to changes in freedom of choice at work and extra work, it was clearly associated with changes of work-related stress over time. Three of four OC subscales exhibited statistically significant associations with ERI.
Conclusions: For the first time, we studied fundamental characteristics of OC as an independent personality variable (trait) or an outcome variable subject to changes in the work environment (state). The association between external ERI and OC over time supports our hypothesis of OC being a state. Further investigations are needed to establish OC as a trait or a state.
Keywords: Coping; Organisational change; Work organisation; Work stress models.