Recovery Sleep versus Emotion Regulation in Predicting Fire Service Shift Workers Stress, Fatigue and Irritability.

: Fire service shift workers are at risk of developing mental health difficulties related to sleep loss and emotion dysregulation. We aimed to clarify the relationship between off-shift recovery sleep and emotion regulation on stress, fatigue and irritability. : A total of 61 fire service shift workers (e.g. firefighter, captain, engineer, paramedic) on a "5/6" shift. : Following five 24-hour shifts, participants reported on emotion regulation as well as daily sleep, stress, fatigue and irritability during six consecutive off-shift recovery days. Mediation analyses examined (1) emotion regulation as a predictor and sleep as a mediator of stress, fatigue and irritability outcomes; and (2) sleep as a predictor and emotion regulation as a mediator of stress, fatigue and irritability outcomes. : Greater self-reported total sleep time predicted lower recovery stress, fatigue, and irritability. Greater subjective sleep efficiency predicted lower recovery stress and fatigue, but not irritability. No significant relationships emerged for objective sleep or emotion regulation variables predicting stress, fatigue or irritability. There were no significant findings with either emotion regulation or sleep variables included as mediators. : These findings suggest that stress management programs for fire service shift workers may be most effective when targeting sleep efficiency and quantity rather than emotion regulation strategies in the off-shift recovery period.