Characteristics of working hours and the risk of occupational injuries among hospital employees: a case‑crossover study
Summary
This case-crossover study analyzed payroll and injury records from nearly 19,000 hospital employees to see how work schedules affected accident risk. Injuries were more likely during evening shifts, on days following night shifts, and after long shifts (10+ hours). The risk also rose when employees worked three or more evening shifts in a week. By contrast, the number of night shifts, quick returns, and total weekly hours were not linked to higher accident risk. Comparing each worker’s injury shifts to their own non-injury shifts showed that it’s the timing and length of shifts, rather than shift work overall, that most influenced safety.
Why It Matters For Night Shift Workers and Night Owls
This study shows that not all parts of a shift schedule carry the same risk. Evening shifts, very long shifts, and the day after a night shift were the periods when accidents were most likely. But simply counting the number of night shifts or weekly hours didn’t predict risk in the same way. For hospital staff and other night workers, that means safety efforts should focus on the most vulnerable points in the schedule — limiting back-to-back evening duties, avoiding very long single shifts, and paying special attention to recovery after nights. Even small adjustments here can help reduce accidents and protect staff well-being.