Explaining educational differences in sickness absence: a population-based follow-up study

Abstract

Objects: There is a marked socioeconomic gradient in sickness absences, but the causes of this gradient are poorly understood. This study examined the role of health and work-related factors as determinants of educational differences in long-term sickness absence in an 8-year follow-up.

Methods: The study comprised a population-based sample of 5835 Finns aged 30-64 years (participation 89%, N=3946) in a register-based 8-year follow-up. This is a novel method to predict the population average of sickness absence days per working year (DWY) based on the expected outcome values using Poisson and gamma regression models.

Results: The difference in the DWY between the lowest and highest educational level was clear among both men (3.2 days/year versus 8.0 days/year) and women (women 4.4 days/year versus 10.1 days/year). Adjusting for physical working conditions, health status and health behavior, and obesity attenuated the differences. Psychosocial working conditions had only a minor effect on the association. After adjusting for health and work-related factors, the difference attenuated by 1.8 days and 2.6 days among men and women, respectively.

Conclusions: Our results suggest that improvements in physical working conditions and reducing smoking, particularly among employees with a low level of education, may markedly reduce educational differences in sickness absence.