Study Links 24-Hour Shifts to Car Accidents

Barger, et. al. “Extended Work Shifts and the Risk of Motor Vehicle Crashes among Interns.” New England Journal of Medicine, Jan. 13, 2005, 352(2). (Download in PDF.)

In an expansive study published in the January 13, 2005 issue of The New England Journal of Medicine, the Harvard Work Hours, Health, and Safety Group found that extended resident work shifts lasting 24 hours or more increase the likelihood of a motor vehicle accident on the after-work commute by more than 100 percent. They also reported that “near-miss” driving incidents occurred five times more frequently for residents when commuting home after working 24 hours or more than after shorter shifts.

The study’s analysis was based on survey data voluntarily submitted by a random sample of 2,737 medical interns in their first post graduate year during the 2002-2003 academic year. The data also indicated that 69 percent of those surveyed relied on motor vehicles as their primary form of transportation to and from their workplace.

“These findings, which are of particular concern because motor vehicle crashes are the leading cause of death in this age group, are consistent with the findings that sleep deprivation degrades performance and that the number of fatigue related crashes increases in proportion to the timespent on task,” wrote the study’s authors in their report. “These data suggest that implementation of a work schedule for interns without any extended shifts could prevent a substantial number of crashes.”