Thirty-five million Americans have sleep disorders, and 95% of them go undiagnosed. This is an expensive statistic: Direct costs related to sleep disorders to the US economy are $15.9 billion.1 

Most scientists know that, excluding traumatic deaths, the largest number of deaths occur during the hours from midnight to 8 am. Although most of these are disease-related deaths, more and more studies are finding that falling asleep at the wheel can be just as deadly. The Department of Transportation estimates that 200,000 automobile accidents each year are sleep-related, and 4% of fatal car crashes are due to drowsy driving—a fatality rate and injury severity level similar to those of alcohol-related crashes.2 Fatigue-related traffic accidents usually involve no more than one or two vehicles, but they are the most destructive to life and property.

The lack of sleep can cause more than traffic accidents. In 1989, when the Exxon Valdez dumped millions of gallons of crude oil into the ocean, investigators determined that sleep deprivation and sleep debt were the culprits: The third mate, who was on watch at the time, was operating on 6 hours of sleep over a 48-hour period and failed to turn the ship in time to avoid danger.2

Other incidents, too, are attributable to sleep debt: In 1995, the cruise ship Star Princess was grounded in Alaska, with repair costs of $27 million. The NTSB concluded that the ship’s pilot was chronically fatigued as a result of sleep apnea.

At the April 2006 FOCUS conference in Nashville, William C. Dement, MD, PhD, Stanford University Center of Excellence for the Diagnosis and Treatment of Sleep Disorders, educated (and amused) a standing-room-only audience on the consequences of sleep debt in students, drivers, and family. What is sleep debt? Dement defines it as “the cumulative daily hours of sleep less than the mean daily amount needed.”3 Most people, he said, need approximately 8 hours of sleep to perform efficiently, and sleep debt can be reduced only by getting extra sleep.

Many people do not realize that they have a sleep debt. They may claim to have had their requisite 8 hours of sleep, but still feel tired. Unbeknownst to them, they might have a sleep disorder, such as apnea, which may interrupt their sleep many times during the night. Even if they acknowledge that they have a sleep problem (62% of adult Americans), only a small number (4%) are seeing a doctor or other health care provider for advice or treatment.4 

Stanford University, through its Primary Care Sleep Education Project,4 is hoping to change those statistics by educating primary care physicians about the importance of asking their patients about sleep problems and referring them for screening. Other facilities also will need to educate primary care physicians to help them recognize sleep disorders and refer such patients to sleep laboratories—thus reducing the impact of sleep deprivation on the economy and on human lives.

1. The sleep crisis in America. Available at: [removed][/removed] Accessed May 9, 2006.

2. Sleep disorders can kill. Available at: [removed][/removed]

3. Dement WC. Sleep loss, extra sleep and performance. Presented at the 6th Annual  Focus Conference; April 22, 2006; Nashville.

4. Stanford University Primary Care Sleep Education Project. Available at: Accessed May 10, 2006.