Work shift duration: a review comparing eight hour and 12 hour shift systems

Area of Science:

• Occupational Health
• Industrial-Organizational Psychology
• Sleep Science

Background:

• Shiftwork is prevalent across industries, significantly influencing worker well-being, performance, and sleep.
• Shift duration is a critical factor in shift system design, impacting various aspects of workers' lives.
• Understanding the differential effects of various shift lengths is crucial for optimizing work schedules.

Purpose of the Study:

• To review and compare the effects of eight-hour versus 12-hour shifts on worker outcomes.
• To examine the impact of shift duration on fatigue, job performance, safety, sleep, and health.
• To discuss organizational factors related to shift system implementation and their consequences.

Main Methods:

• Conducted comprehensive literature searches (manual and electronic) on shiftwork research.
• Focused specifically on studies comparing eight-hour and 12-hour shift durations.
• Synthesized existing evidence to evaluate comparative effects.

Main Results:

• Research findings comparing eight-hour and 12-hour shifts are largely equivocal, with limited clear differences.
• Potential benefits of 12-hour shifts include lower stress, improved well-being, better sleep quality, and enhanced family relations.
• Key concerns with 12-hour shifts involve increased fatigue and potential safety risks, noting that active work time may exceed 12 hours.

Conclusions:

• The impact of extended workdays, particularly the chronic effects of compressed working weeks, requires further systematic investigation.
• Longitudinal studies are needed to fully understand the long-term consequences of extended work hours on workers.
• Further research should explore the nuanced effects of shift duration beyond simple hour comparisons.