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Extended work hours and risk of acute occupational injury: A case-crossover study of workers in manufacturing
1Yale Occupational and Environmental Medicine Program, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Objective:
This study was designed to determine whether injury risk among manufacturing workers was related to hours worked during the previous week.
Methods:
A case-crossover design was utilized to contrast hours worked prior to an injury shift with those worked prior to a non-injury shift for hourly workers. Paired t-tests were used to determine significance of the difference. Conditional logistic regression was used to assess dose-response.
Results:
Hours worked prior to injury significantly exceeded hours during the control week. Workers who worked more than 64 hr in the week before the shift had an 88% excess risk compared to those who worked 40 hr or fewer, P < 0.05.
Conclusion:
The study provides evidence that injury risk is related to time worked during the previous week. Control of overtime in manufacturing may reduce risk of worker injury.
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