ABSTRACT: Patients with obstructive sleep apnea (OSA) are at increased risk for motor vehicle crashes as a result of excessive sleepiness. However, a number of factors complicate risk assessment. For example, self-reported sleepiness and the severity of OSA do not appear to be good predictors of accident risk. Many persons with OSA do not accurately perceive their level of drowsiness-self-reported sleepiness does not correlate well with objective measures, such as results of the Multiple Sleep Latency Test. Moreover, it is not clear whether objective tests can reliably predict accident risk in the real world, as opposed to during simulated driving. The indications for-and benefits of-restricting driving in patients with OSA have not been established. However, there is good evidence that the use of continuous positive airway pressure significantly reduces the risk of crashes in these patients. (J Respir Dis. 2008;29(12):459-464)
Excessive daytime sleepiness is a common symptom of obstructive sleep apnea (OSA) and is associated with increased risk of motor vehicle crashes (MVCs). A patient's involvement in a drowsiness-related accident resulting in serious injury or death is the most likely situation in which a physician could face charges of legal negligence in the management of OSA. The AMA policy H-15.958 (Fatigue, Sleep Disorders, and Motor Vehicle Crashes) states that physicians should "inform patients about the personal and societal hazards of driving or working while fatigued and advise patients about measures they can take to prevent fatigue-related and other unintended injuries."1
State regulations governing physicians' reporting of patients with medical conditions that may render them unfit for driving vary from no requirement to mandatory reporting of all patients with any diagnosis listed as reportable. Some states require reporting of patients with listed conditions only if the physician believes the condition significantly impairs function. The AMA policy also states that physicians should "become familiar with the laws and regulations concerning drivers and highway safety in the state(s) where they practice."1
A task force of the European Respiratory Society on public health and medicolegal implications of sleep apnea concluded that "whatever the legislation, the clinician has a responsibility to inform his patients of the risks related to sleepiness and to discourage him from driving as long as he is not effectively treated."2 In 2 instances in Canada, physicians were found liable because of failure to report patients potentially medically unfit to drive before the patients were involved in MVCs.3 However, these were not sleep-related conditions and, as of this writing, I am not aware of any instance in the United States in which a physician was held liable for failure to report a patient with a sleep disorder who subsequently had an MVC. There is clearly a potential for this to occur. Physicians have an ethical, if not legal, responsibility to inform their patients with OSA about the increased risk of crashes that are associated with this condition and to counsel them to refrain from driving while drowsy.
In this article, I will review the current understanding of the medical aspects of the risk of crashes for patients with OSA and the effect of therapy on that risk. I also will discuss the implications of making judgments about restricting driving in these patients.
WHAT ARE THE RISKS?
Up to 20% of MVCs have been attributed to inattention associated with excessive sleepiness.4,5 Stutts and colleagues6 interviewed about 1000 persons who had been in MVCs and about 400 persons who had not been in an MVC (control group). Only 1.3% of those classified by law officers as being asleep at the time of the crash had previously received a diagnosis of a sleep disorder; however, 25% admitted to having driven while drowsy more than 10 times and 91% admitted to having fallen asleep while driving at least once.