Is effort-reward imbalance at work a risk factor of long-term sickness absence in Denmark?

Introduction:

The mismatch between high efforts and low rewards at work, denoted effort-reward imbalance (ERI), is hypothesized to increase risk of ill-health. However, a previous study reported that ERI was unrelated to risk of long-term sickness absence (LTSA) in Denmark. As the study was limited by a relatively small sample, we investigated in a new study the prospective association between ERI and risk of LTSA in a sample of more than 50,000 employees.

Methods:

We included respondents from the 2012, 2014 and 2016 waves of the Work Environment and Health in Denmark study (50.4% response rate). Information on LTSA, defined as absence spells ≥6 weeks, was retrieved from a nationwide register of social transfer payments. Respondents with LTSA during two years before baseline were excluded, yielding a sample of 53,801 participants. We assessed efforts and rewards with proxy measures, calculated an ERI-ratio and categorized the ratio into quartiles. Using Cox regression, we estimated the association between ERI and onset of LTSA during 12 months follow-up, adjusted for age, sex, and education.

Results:

We identified 2,279 LTSA events. The hazard ratio for LTSA among participants in the highest compared to the lowest ERI-quartile was 1.70 (95% CI: 1.51 – 1.91) after adjustments for covariates. Analyses across quartiles indicated a dose-response association. ERI was associated with LTSA in all educational groups, with the strongest estimate in the low educational group.

Discussion:

Effort-reward imbalance at work is a risk factor of long-term sickness absence in Denmark. Further research should explore potentials for preventive workplace initiatives.