Transitioning to shift work: Predictors of shift work tolerance and shift work disorder

This thesis explored shift work tolerance (SWT) and related health outcomes, sleep behaviour, and shift work disorder (SWD) during the transition to shift work. After starting shift work, sleep duration and regularity declined, while sleep opportunity, SWD risk and mental health symptoms increased. The thesis also identified predictors of SWT and SWD. Sleep-related factors at the beginning of workers’ careers predicted SWT, while pre-shift work mental health predicted SWD. Furthermore, protective factors (e.g., social support) interacted with SWD risk to influence health outcomes. Findings highlight the need to support workers in their early career to reduce SWD and promote SWD.