Effort-reward imbalance, procedural injustice and relational injustice as psychosocial predictors of health: complementary or redundant models?

OBJECTIVE Effort-reward imbalance at work is an established psychosocial risk factor but there are also newer conceptualisations, such as procedural injustice (decisions at work lack consistency, openness and input from all affected parties) and relational injustice (problems in considerate and fair treatment of employees by supervisors). The authors examined whether procedural injustice and relational injustice are associated with employee health in addition to, and in combination with, effort-reward imbalance. METHODS Prospective survey data from two cohorts related to public-sector employees: the 10-Town study (n = 18 066 (78% women, age range 19-62) and the Finnish Hospital Personnel study (n = 4833, 89% women, age range 20-60). Self-rated poor health, minor psychiatric morbidity and doctor-diagnosed depression were assessed at baseline (2000-2) and at follow-up (2004). To determine incident morbidity, baseline cases were excluded. RESULTS In multivariate models including age, sex, occupational status and all three psychosocial factors as predictors, high effort-reward imbalance and either high procedural injustice or high relational injustice were associated with increased morbidity at follow-up in both cohorts. After combining procedural and relational injustice into a single measure of organisational injustice, high effort-reward imbalance and high injustice were both independently associated with health. For all outcome measures, a combination of high effort-reward imbalance and high organisational injustice was related to a greater health risk than high effort-reward imbalance or injustice alone. CONCLUSION Evidence from two independent occupational cohorts suggests that procedural and relational components of injustice, as a combined index, and effort-reward imbalance are complementary risk factors.