A study of the potential role of sleep disorders in new zealand road traffic accidents

Aim. To document the frequency of sleep disorders in drivers attending the Wellington Accident and Emergency (A & E) services with injury following a road traffic accident. Method. Between April 1999 to April 2000 we prospectively recruited injured drivers who completed a traffic accident, health and sleep questionnaire and underwent comprehensive diagnostic polysomnography. Subjects were excluded if they suffered severe neurological sequelae such as brain or spinal cord injury, severe chest or multiple trauma. Subjects with a tracheostomy and those where alcohol or drug intoxication was implicated were also excluded. Analysis. Comparisons between subjects with and without sleep disordered breathing were made using T-tests for continuous data and Chi squared tests for dichotomous variables. Results. Of the 120 eligible drivers 40 agreed to participate. Sixteen (40%) felt they rarely got enough sleep, 27 (67%) were unrefreshed on waking and 6 (15%) felt drowsy or fell asleep prior to the accident. Obstructive sleep apnoea (OSA) as determined by polysomnographic criteria was found in 14 (36%) and by combined polysomnography and clinical criteria in 12 (30%). Conclusions. Daytime somnolence and obstructive sleep apnoea were commonly found in drives attending a New Zealand A & E Department with accidents resulting in injury. Driver fatigue and OSA should be considered as a potential contributing factor in road traffic accidents.