Sleep versus non-sleep-related fatal road accidents

To study different factors that are associated with fatal sleepiness-related motor vehicle accidents (FSMVA) and in other types of fatal motor vehicle accidents (FMVA) in Finland.

All FMVA that were caused by falling asleep at the wheel (FSMVA) during the years 2005-2014 were investigated using OTI (Finnish Crash Data Institute) data. The control group consisted of 136 drivers who died in other types of FMVA in 2013. A total of 258 accidents were investigated.

The mean age of the 122 drivers in the FSMVA group was 44 (standard deviation 19) years; there were 100 men (82%) and 22 women. The mean age of the 136 control drivers was 45 (standard deviation 19) years; there were 116 men (85%) and 20 women. Short sleep time (<6 h) during the previous night before the accident was the most prominent independent risk factor for FSMVA compared to other FMVA (p < 0.05). None of the other driver-related factors (diseases, blood alcohol level, illegal drugs, body mass index, medications, age, sex) differed significantly between the two groups.

Short sleep is a major cause of fatal sleepiness-related motor vehicle accidents. Driver health factors such as sleep apnea or acute/chronic diseases as well as use of sedative medications and drugs are known risk factors for FSMVA, but these factors are associated also with other types of accidents. Healthy individuals are at risk for falling asleep while driving if they are sleep deprived. All drivers should be aware of the importance of adequate sleep.