Occupational class differences in long sickness absence: a register-based study of 2.1 million Finnish women and men in 1996-2013.

OBJECTIVES: Sickness absence is consistently higher in lower occupational classes, but attempts to analyse changes over time in socioeconomic differences are scarce. We examined trends in medically certified sickness absence by occupational class in Finland from 1996 to 2013 and assessed the magnitude and changes in absolute and relative occupational class differences.

DESIGN: Population-based, repeated cross-sectional study.

SETTING: A 70% random sample of Finns aged between 25 and 63 years in the years 1996-2013.

PARTICIPANTS: The study focused on 25- to 63 year-old female (n between 572 246 and 690 925) and male (n between 525 698 and 644 425) upper and lower non-manual and manual workers. Disability and old age pensioners, students, the unemployed, entrepreneurs and farmers were excluded. The analyses covered 2 160 084 persons, that is, 77% of the random sample.For primary and secondary outcome measures, we examined yearly prevalence of over 10 working days long sickness absence by occupational class. The Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were used to assess the magnitude and changes in occupational class differences.

RESULTS: Compared with mid-1990s, sickness absence prevalence was slightly lower in 2013 in all occupational classes except for female lower non-manual workers. Hierarchical occupational class differences in sickness absence were found. Absolute differences (SII) peaked in 2005 in both women (0.12, 95% CI 0.12 to 0.13) and men (0.15, 95% CI 0.14 to 0.15) but reached the previous level in women by 2009 and decreased modestly in men until 2013. Relative differences narrowed over time (p<0.001) but levelled off by 2013.

CONCLUSIONS: Sickness absence prevalence is currently slightly lower in almost all occupational classes than in the mid-1990s, but occupational class differences have remained large. Ill health and poor working conditions especially in the lower occupational classes should be targeted in order to reduce sickness absence and to achieve longer working lives.