Night shift workers at high risk of car crashes: Study

Working night shift might put workers at increased risk of drowsy driving crashes due to disruption of sleep-wake cycles and insufficient sleep, a new study has warned.

A study by researchers at Brigham and Women's Hospital (BWH) in the US evaluated the daytime driving performance of night shift workers following a night of shift work as against driving after a night of sleep.

They found that 37.5 per cent of drivers participating in a test drive after working the night shift were involved in a near-crash event.

However, the same drivers with sufficient sleep the night before the tests had zero near-crashes, according to the researchers.

The results demonstrated, for the first time, an elevated risk of drowsy driving related to motor vehicle crashes, as also, an increase in self-reported and biological measures of drowsiness when operating a real motor vehicle during the daytime following night shift work.

"Drowsy driving is a major - and preventable - public health hazard," said Charles A Czeisler, chief of the Division of Sleep and Circadian Disorders at BWH.

"These findings help to explain why night shift workers have so many more motor vehicle crashes than day workers, particularly during the commute home," said Czeisler, corresponding author of the study. The study involved, 16 night shift workers completing a pair of 2-hour driving sessions on a closed driving track.

The study further found sleep-related impairment was evident within the first 15 minutes of driving. The study was published Monday in the journal Proceedings of the National Academy of Sciences.

''Even veteran night shift workers were vulnerable to the risks associated with drowsy driving, and exhibited reactions similar to behaviours observed in drivers with elevated blood alcohol concentrations,'' lead author Michael Lee of the Brigham and Women's Hospital (BWH) said in a statement.

''A short commute for these drivers is shown to be potentially dangerous and the longer the drive, the greater the risk,'' Lee said.

''These findings help to explain why night shift workers have so many motor vehicle crashes than day workers, particularly during the commute home,'' Czeisler said.

''Night shift workers should be advised of the hazards of drowsy driving and seek alternate forms of transportation after night shift work.''