Background:
Precarious work is characterised by high job insecurity, low income, and reduced rights and social protections. Current evidence suggests that precarious work is a risk factor for self-rated physical health. It has also been demonstrated that precarious workers are vulnerable to sleep disturbances and psychological distress. This study explored the hypothesis that the relationship between precarious employment and physical health is mediated by poor sleep and psychological distress.

Methods:
Data were obtained from the Household, Income and Labour Dynamics in Australia (HILDA) survey (2017). A novel precarious employment score (PES) was developed using exploratory factor analysis and confirmatory factor analysis in 8,127 workers. Structural equation modelling was used to evaluate the mediating effect of sleep quality and psychological distress on the relationship between precarious employment and physical health (SF-36 physical health subscale), after controlling for age, sex, marital status, educational attainment, and tenure.

Results:
The PES identified 648 workers in high precariousness and 7,431 workers in a low or moderate level of precariousness. There was a significant direct association between precarious employment and physical health (P<0.001). We also observed a significant change due to sleep quality (Indirect path coefficient=0.14, 95% CI: 0.06-0.22, P<0.001) and psychological distress (Indirect path coefficient=0.23, 95% CI: 0.11-0.35, P<0.001) in the association between precarious employment and physical health. Conclusion: Sleep quality and psychological stress play a mediating role in the association between precarity and physical health. Encouraging precarious employees to prioritise sleep and well-being may mitigate the adverse effects of precarious work on their physical health. Effective measures should be developed to reduce the role of precarity in psychological distress.