Effort-reward imbalance and relational injustice at work predict sickness absence: the Whitehall II study.

Objectives: Sickness absence is a major occupational health problem, but evidence for associations between potentially modifiable psychosocial work factors and sickness absence is still scarce. We studied the impact of relational justice and effort-reward imbalance on subsequent rates of sickness absence.

Methods: The Whitehall II prospective cohort study of British civil servants, 10,308 men and women, was established between 1985 and 1988. Indicators of effort-reward imbalance and the relational component of organizational justice were constructed from questions included at baseline. Participants were classified into three groups (low, intermediate, and high) for both effort-reward imbalance and relational justice. Short (< or =7 days) and long (>7 days) spells of sickness absence during 1985-1989 and 1991-1995 were used to study immediate and longer term effects of work characteristics.

Results: After adjustment for age, employment grade, and baseline health, men and women with low relational justice had increased risks of long spells of sickness absence of 14% and 28% in comparison to men and women experiencing high levels of justice. Similar effect sizes (25% and 21%) were found for high vs. low effort-reward imbalance. Both work measures also predicted short spells of sickness absence. Effort-reward imbalance (men and women) and relational justice (women only) each predicted long spells of sickness absence independently of the other.

Conclusions: Both relational justice and effort-reward imbalance are important determinants of sickness absence. Workplace interventions to improve these aspects of working conditions have the potential to reduce levels of sickness absence.