The impact of overtime and long work hours on occupational injuries and illnesses

The impact of overtime and long work hours on occupational injuries and illnesses: new evidence from the United States - Dembe et al., Occupational and Environmental Medicine
Results: After adjusting for those factors, working in jobs with overtime schedules was associated with a 61% higher injury hazard rate compared to jobs without overtime. Working at least 12 hours per day was associated with a 37% increased hazard rate and working at least 60 hours per week was associated with a 23% increased hazard rate. A strong dose-response effect was observed, with the injury rate (per 100 accumulated worker-years in a particular schedule) increasing in correspondence to the number of hours per day (or per week) in the workers' customary schedule.