Self-Certified Sickness Absence among Young Municipal Employees—Changes from 2002 to 2016 and Occupational Class Differences

We examined changes in self-certified, one-to-three day sickness absence (SA) among young employees from 2002 to 2016 and the magnitude of occupational class differences during that period. All 18–34-year-old employees of the City of Helsinki, Finland were included (2002–2016, n = ~11,725 per year). Employer’s personnel and SA registers were used. Occupational class was categorized to four groups. Changes in self-certified SA from 2002 to 2016 were analyzed with Joinpoint regression and the magnitudes of occupational class differences were estimated with the relative index of inequality (RII). Most of the trends first increased and turned to decrease in 2007/2010. Managers and professionals had the least amount of SA, but steadily increasing trends were observed among men. Self-certified SA followed only partially the typical socioeconomic gradient, as routine non-manuals had the highest levels of SA. The magnitude of occupational class differences in self-certified SA was stable during the study period only among women. Self-certified SA and occupational class differences have increased in recent years among men in the lower occupational classes. Socioeconomic differences exist in self-certified SA among young employees, but gradient is only partial. Overall, high amounts of self-certified SA especially in the lower occupational classes require further studies and preventive measures.