A very interesting retrospective case-series observational study conducted using data from the West Australian Sleep Health Study at a tertiary hospital-based sleep clinic. It describe the incidence rate of motor vehicle crashes (MVCs) in patients with obstructive sleep apnea (OSA); and investigates MVC risk factors in OSA patients. 2673 patients were assessed for suspected sleep disordered breathing. Questionnaire data were collected including age, sex, years of driving, near-misses and MVCs, sleepiness, and consumption of alcohol and caffeinated drinks and an overnight laboratory-based polysomnography was performed.
The authors show that the crash rate was 0.06 MVC/person-year compared with the general community crash rate of 0.02 MVC/person-year. They concluded that untreated OSA was associated with an increased risk of near-misses in men and women and an increased risk of MVCs in very sleepy men. There was a strong association between excessive daytime sleepiness and increased report of near-misses. The data supports the observation that it is those patients with increased sleepiness regardless of OSA severity who are most at risk.