Driving Performance and Obstructive Sleep Apnea

The increasing prevalence of obstructive sleep apnea (OSA), especially among commercial vehicle operators, is a growing concern in terms of accident causation. To examine more thoroughly the relationship between severity of OSA and driving performance, a preliminary study was conducted to compare performance between drivers with untreated OSA and normal drivers. Twenty-eight adult participants, aged 27 to 66 years, completed a 45-min rural simulator drive. Several categories of driving performance, including lane keeping and velocity keeping, were evaluated. During the lane-keeping evaluation, participants with moderate to severe OSA had excursions outside the lane to the shoulder that were significantly greater in terms of time and exposure area compared with the mild and no-OSA participants. During the velocity-keeping evaluation, participants with moderate to severe OSA had significantly more variable velocity control during the later segments of the drive than did mild and no-OSA participants. On the basis of these findings, there is evidence that it will be feasible to identify differences in driving performance between various levels of OSA severity. Two potential extensions of this research could significantly impact traffic safety. The first is to further define and refine critical thresholds on the Apnea/Hypopnea Index scale at which driver performance begins to degrade. The second extension of this research is to develop a protocol and metrics for determining the effectiveness of various treatments (e.g., surgery, continuous positive airway pressure) at restoring normal driving performance.