Bedtime rumination mediates the burnout-insomnia link and relates to shift adaptation in emergency department staff

Burnout and sleep disturbances are highly prevalent among emergency department staff, yet their mechanisms within shift work remain poorly understood. This study examined whether cognitive pathways explain the comorbidity between burnout and insomnia, and how these processes relate to behavioral adaptation to shift load, in a secondary pre-intervention analysis of the REST randomized controlled trial. Fifty-eight physicians and nurses completed the Maslach Burnout Inventory, Pittsburgh Sleep Quality Index, Insomnia Severity Index, and Pre-Sleep Arousal Scale (somatic and cognitive subscales; cognitive subscale reflecting bedtime rumination), together with shift work disorder screening items. Work schedules informed shift load and actigraphy provided total sleep time and sleep regularity to classify individual shift adaptation profiles. Individuals were considered vulnerable when their sleep metrics were lower than expected given their schedule-related load. Burnout, insomnia and pre-sleep arousal were strongly interrelated. Cognitive pre-sleep arousal fully mediated the association between burnout and insomnia, identifying bedtime rumination as a central cognitive pathway. In parallel, objective sleep-based adaptation profiles showed that vulnerable adaptors reported higher burnout, emotional exhaustion, and insomnia. Together, these findings support a cognitive-behavioral framework linking stress-related cognition to both subjective sleep complaints and objective shift adaptation in shift-working healthcare professionals.