Safety Incidents Associated with Extended Working Hours: Meta‑analysis
Summary
This systematic review and meta-analysis examined whether extended working hours are linked to safety incidents (accidents, near-misses, and injuries) across multiple industries. The authors searched five databases through December 2020, screened 10,072 records, and synthesized 22 eligible studies. Across the pooled evidence, working more than 12 hours in a day and exceeding about 55 hours in a week were each associated with a higher risk of safety incidents. In contrast, smaller increases in daily or weekly hours did not show a consistent association. The authors rated the overall certainty of the evidence as low, noting the need for higher-quality studies, but the pattern for the longest hours was consistent enough to warrant attention.
Why It Matters For Night Shift Workers and Night Owls
Night work is performed when alertness is naturally at its lowest; extending duty time at these hours compounds fatigue, slows reaction speed, and increases slips in attention—particularly toward the end of a shift and across consecutive nights. The findings support treating roster design (adequate recovery between duties, limits on consecutive hours, and oversight of weekly accumulation) as core safety controls in night-work settings. In practice, this helps reduce end-of-shift errors, supports safer patient care and handovers, and lowers commuting risk after overnight duties. It also provides an evidence base workers and schedulers can use to shape rosters that manage cumulative fatigue rather than relying on individual resilience.
Notes
Open access safety meta‑analysis.