Truck crashes are a significant public health hazard causing thousands of deaths and injuries each year, with driver fatigue and sleepiness being major causes. A new study has confirmed previous findings that obesity-driven testing strategies identify commercial truck drivers with a high likelihood of obstructive sleep apnea (OSA) and suggests that mandating OSA screenings could reduce the risk of truck crashes.
OSA is a syndrome characterized by sleep-disordered breathing, resulting in excessive daytime sleepiness, sleep attacks, psychomotor deficits, and disrupted nighttime sleep. It increases the risk of motor vehicle accidents, and is common among truck drivers. Approximately 2.4 to 3.9 million licensed commercial drivers in the U.S. are expected to have OSA. In addition to being unrecognized or unreported by drivers, OSA often remains undiagnosed by many primary care clinicians despite the fact that OSA increases the risks of hypertension, diabetes mellitus, and heart disease.
Philip Parks, MD, MPH, medical director of Lifespan's employee health and occupational services, is the study's lead author. He worked with researchers at the Cambridge Health Alliance on the study published in the March 2009 edition of the Journal of Occupational and Environmental Medicine. Parks says, "It is well-known that obesity, a leading risk factor for obstructive sleep apnea, is on the rise in the United States. Truck drivers with sleep apnea have up to a 7-fold increased risk of being involved in a motor vehicle crash."
Over the 15-month study period, 456 commercial drivers were examined from over 50 different employers. Seventy-eight (17%) met the screening criteria for suspect OSA. These drivers were older and more obese, and had a higher average blood pressure. Of the 53 drivers who were referred for sleep studies, 33 did not comply with the referral and were lost to follow-up. The remaining 20 were all confirmed to have OSA, but after diagnosis, only one of these 20 drivers with confirmed OSA complied with treatment recommendations.
Parks also notes, "Although it is not surprising, it is concerning that we found that drivers with sleep apnea frequently minimize or underreport symptoms such as snoring and daytime sleepiness. In our study, the majority of truck drivers did not follow through on physician recommendations for sleep studies and sleep apnea treatment." He continues, "As a result, it is possible that many of the 14 million truck drivers on American road have undiagnosed or untreated sleep apnea."
Stefanos N. Kales, MD, MPH, Medical Director of Employee and Industrial Medicine at Cambridge Health Alliance, is the study's senior author. Kales says, "It is very likely that most of the drivers who did not comply with sleep studies or sleep apnea treatment sought medical certification from examiners who do not screen for sleep apnea and are driving with untreated or inadequately treated sleep apnea."
The study, published today by the Journal of Occupational and Environmental Medicine, has significant policy ramifications, as the Federal Motor Carrier Safety Administration is currently deliberating recommendations to require sleep apnea screening for all obese drivers based on body mass index or "BMI" (BMI is calculated based on height and weight). The Administration requires medical certification of licensed commercial drivers at least every two years. These occupational medicine exams present a unique opportunity for detecting OSA as part of determining a driver's safety behind the wheel.
"OSA screenings of truck drivers will be ineffective unless they are federally mandated or required by employers," said Kales. The study's authors also support the prohibition of "doctor shopping." Dr. Kales added, "Such action would prohibit drivers diagnosed with a serious disorder that might limit driving or require treatment to seek out more lenient or less rigorous medical examiners."