Objective The aim of the present study was to investigate the effects of the duration and timing of rest breaks on traumatic injury risk across a shift in a relatively large sample of hospitalized workers with severe work-related hand injury in the People’s Republic of China (PRC).

Methods Hospitalized workers from multiple industries with severe work-related traumatic hand injury were recruited from 11 hospitals in three industrially-developed cities in the PRC: Ningbo, Liuzhou, and Wuxi. Cox regression was used to compare time into the work shift of injury across categories of rest breaks, while evaluating several potential covariates including age, gender, work hours, work start time and duration, injury day and time, duration and quality of last sleep, alertness/sleepiness, job control, and several transient work-related factors. Effect modification by work shift start time was also evaluated.

Results With four days of injury, 703 hospitalized workers completed a face-to-face interview. After adjusting for significant covariates, workers with rest breaks of 1–30, 31–60, and >60 minutes were able to work significantly (P<0.001) longer into their work shift without an injury (>5 hours) then those with no rest break. A significant interaction was also observed between rest break status and start time of the work shift.

Conclusion The results of this study suggest that rest breaks of any duration have a significant effect on delaying the onset of a work-related injury, which is modified by the time of day in which a shift begins.

Key terms China; epidemiology; fatigue; injury; occupational injury; People's Republic of China; rest break; shift work; sleep; sleep duration; sleep quality; work shift