How valid is a short measure of effort-reward imbalance at work? A replication study from Sweden

Objectives There is an urgent need for validated measures of health-adverse psychosocial work environments. We tested the validity of a newly developed short version of the original questionnaire measuring effort-reward imbalance at work (ERI). Methods The study sample comprised working men and women (n=4771) participating in the Swedish Longitudinal Occupational Survey of Health (SLOSH), a nationally representative longitudinal cohort study, in 2006 and 2008. Structural equation modelling was applied to test factorial validity, using the ERI scales. Furthermore, criterion validity was explored with two prospectively assessed health indicators, poor self-reported health and depressive symptoms. Results are based on logistic and linear regression analyses, with appropriate confounder control. Results The short version of the ERI questionnaire (16 items) provides satisfactory psychometric properties (internal consistency of scales, confirmatory factor analysis with a good model fit of the data with the theoretical structure). All scales, and the effort-reward ratio, were prospectively associated with an increased risk of poor general self-rated health and depressive symptoms, indicating satisfactory criterion validity. Conclusion This short version of the ERI questionnaire provides a psychometrically useful tool for epidemiological studies focused on the health-adverse effects of work and employment in the context of a globalised economy.