Sleepiness, like excessive speed, alcohol, aggressive driving, and inclement weather, contributes to or causes motor vehicle crashes. In the past few years, sleep as a factor in automobile crashes has begun to be investigated but, without sufficient data, is still not fully understood. One reason for the lack of data on the role of sleepiness in crashes is that not all jurisdictions’ accident reports include “sleepiness” (or a term used as its equivalent) as a factor. In addition, it is often difficult to ascertain at the scene that sleepiness was involved: there is no simple procedure like a blood alcohol content test to confirm a driver’s sleepiness at the time of the crash. Moreover, not all investigators are yet properly trained on the role sleep may play in crashes. Instead, when sleepiness is cited as the cause, it is often only when there are no brake marks or other attempts to avoid the collision, when the crash occurs during the sleepy phase of the circadian rhythm, and/or when the driver admits falling asleep. (However, self-report from the driver has been shown to be an unreliable because people either deny falling asleep or are unaware of falling asleep at the wheel.)
Nonetheless, sleepiness does cause and contribute to motor vehicle crashes; in fact, a higher percentage of fall-asleep crashes result in fatalities than those attributed to other causes. As more attention is paid to these crashes, the steps that can reduce these crashes need to be explored as well.
Sleepiness is generally caused by sleep deprivation, untreated sleep disorders, and circadian rhythm factors such as jet lag and shiftwork. In addition, sleepiness may be caused by medication (prescription or over-the-counter) and alcohol, or a combination. The most common cause of sleepiness is sleep deprivation. Studies to date indicate that most fall-asleep crashes are caused by young males under the age of 26, individuals who are most likely to be sleep-deprived. The number of sleep-related crashes due to untreated sleep disorders is not known.
Sadly, Americans have not been taught that sleep, like exercise and proper diet, is crucial to good health. The American Sleep Apnea Association strongly supports efforts to educate Americans about the importance of sleep, the causes of sleepiness, and the potential consequences of sleepiness: people must understand that ignoring sleepiness may be fatal. If drivers are sleepy, they should know not to get behind the wheel. Further, drivers should know what steps to take in order to correct the cause of the sleepiness or to prevent sleepiness.
Likewise, the ASAA supports efforts to educate Americans about the symptoms of sleep disorders so that these disorders can be diagnosed and treated appropriately. Untreated sleep apnea can cause medical problems such as high blood pressure and other cardiovascular disease; when clinically significant, sleep apnea should be treated regardless of driving status. The ASAA does not believe that individuals who are excessively sleepy because of a diagnosed but untreated sleep disorder should drive; they are a risk to themselves and others. However, there is no indication that an adequately treated sleep disorder increases anyone’s risk for a fall-asleep crash. In fact, recent research indicates that treatment of sleep apnea with a CPAP (Continuous Positive Airway Pressure) machine* reduces the risk of a fall-asleep crash to that found in the general population.
Some states now have or are considering regulations to restrict the driving privileges of individuals with sleep disorders. The ASAA is concerned that such restrictions will discourage people who think they may have a sleep disorder from being diagnosed if they fear being diagnosed will lead unnecessarily to the revocation of their license. Such regulations may have an unintended effect and may harm efforts to reduce the number of Americans with undiagnosed and untreated sleep disorders. However, regardless of the regulations, health care professionals who recognize that their patient presents a risk on the road should not hesitate to warn the patient about driving until the cause of the sleepiness is investigated and remedied. In certain situations, such as when the driver’s condition is unmanageable or when the driver is unwilling to restrict driving until effective treatment has been instituted, health care professionals may need to seek advice from the local department of motor vehicles.
The goal of keeping sleepy drivers–no matter what the cause of the sleepiness–off the road must be kept in mind in formulating regulations and devising educational material. The ASAA will continue to work with other health care associations, traffic safety organizations and federal, state, and local agencies on how sleep apnea affects road safety.
Approved by the ASAA Board of Directors June, 1997 and revised October, 2001.
*A CPAP (Continuous Positive Airway Pressure) machine is the most common treatment for sleep apnea. Usually applied via a nasal mask, CPAP prevents apneas by splinting the airway open. Other treatment options include oral appliances and surgery.