The Magnitude of Occupational Class Differences in Sickness Absence: 15-Year Trends among Young and Middle-Aged Municipal Employees

Background: Our aim was to examine the magnitude of relative occupational class differences in sickness absence (SA) days over a 15-year period among female and male municipal employees in two age-groups. Methods: 18–34 and 35–59-year-old employees of the City of Helsinki from 2002 to 2016 were included in our data (n = ~37,500 per year). Occupational class was classified into four groups. The magnitude of relative occupational class differences in SA was studied using the relative index of inequality (RII). Results: The relative occupational class differences were larger among older than younger employees; the largest differences were among 35–59-year-old men. Among women in both age-groups the relative class differences remained stable during 2002–2016. Among younger and older men, the differences were larger during the beginning of study period than in the end. Among women in both age-groups the RII values were between 2.19 (95% confidence intervals (CI) 1.98, 2.42) and 3.60 (95% CI 3.28, 3.95). The corresponding differences varied from 3.74 (95% CI 3.13, 4.48) to 1.68 (95% CI 1.44, 1.97) among younger and from 6.43 (95% CI 5.85, 7.06) to 3.31 (95% CI 2.98, 3.68) among older men. Conclusions: Relative occupational class differences were persistent among employees irrespective of age group and gender. Preventive measures should be started at young age.