A twin study of employment uncertainty and sickness absence due to mental disorders accounting for familial factors and personality

Abstract

Abstract While both insecure employments and sickness absence due to mood, anxiety, and stress-related disorders are common on the labor market and pose major public health concerns, their interrelations are not well understood. This prospective twin study examined the association between employment uncertainty and sickness absence due to mental disorders, accounting for unmeasured potential confounding by genetics and shared early environment and assessing the impact of personality. The study was performed using survey and register data from 9,326 twins derived from the Swedish Twin project of Disability Pension and Sickness Absence (STODS). Logistic regression estimated odds of medically certified sickness absence benefits following employment uncertainty. Co-twin control analyses using conditional logistic regression addressed unmeasured confounding. Interactions with extraversion and neuroticism were assessed on both multiplicative and additive scales. Employment uncertainty was associated with sickness absence due to mood, anxiety, and stress-related disorders (adjusted OR 1.46, 95% CI 1.30–1.64) in the overall sample. In co-twin control analyses ( n = 434 pairs) the association was attenuated (OR 1.09, 95% CI 0.75–1.58), suggesting that the observed association may be explained by genetics and/or shared early environment. No clear evidence of moderation by personality was observed, although findings for neuroticism were inconsistent.