A Systematic Review and Revised Meta-analysis of the Effort-Reward Imbalance Model of Workplace Stress and Hypothalamic-Pituitary-Adrenal Axis Measures of Stress.

Objective: Despite considerable research in the past 20 years into associations between the effort-reward imbalance (ERI) model and various health outcomes, the mechanisms responsible for the association remain unclear. Our meta-analysis assessed the associations of ERI and overcommitment (OC) in the workplace with measures from the hypothalamic-pituitary-adrenal (HPA) axis.

Methods: Electronic databases were searched with the phrase "effort * reward * imbalance," which yielded 319 studies leading to 56 full-text studies being screened. Thirty-two studies within 14 articles met the inclusion criteria and were meta-analyzed using mixed- and random-effects models.

Results: Greater ERI was associated with increased HPA axis activity (r = 0.05, p = .02, k = 14, n = 2461). The cortisol waking concentrations (r = 0.11, p = .02, k = 6, n = 493) were the only subgroup associated with ERI. Meta-regression revealed that studies that contained more men had stronger ERI to HPA marker associations. When all HPA markers were considered collectively, OC was not associated with greater HPA axis activity (r = 0.01, p = .70, k = 10, n = 1684), with only cortisol (pm) associated with OC (r = -0.24, p = .02, k = 2, n = 95).

Conclusions: ERI and OC were associated with HPA responsivity. Although the cortisol waking concentrations and not the CAR were associated with ERI, this may be due to heterogeneity in the experience of stress between studies. Future studies should consider the concurrent assessment of burnout to better assist the interpretation of ERI with HPA responsivity.