Extended work periods.

A literature review of 105 studies on the effects of extended daily working hours was conducted. Potential negative effects of extended working hours are discussed: More accidents on the job; more accidents off the job; reduced duration and quality of sleep due to moonlighting; sleepiness; reduced alertness; fatigue; adverse effects on performance; prolonged toxic exposure; adverse effects on health; increased absenteeism; problems communicating with managers; and problems while driving home. Potential positive effects of extended working hours are discussed: Less travel time and costs; more time for the family, social life, and domestic duties; increased satisfaction with working hours; fewer handovers; and less overtime. No firm conclusions can be drawn because of the partly contradictory results and the methodological problems of many studies. However, caution is advised when considering the introduction of extended work shifts, particularly where public safety is at stake. A checklist is provided (concerning work load, breaks, staffing level, systematic assessments of health and safety factors) to support decisions for or against the use of extended work shifts.