"Truck drivers with sleep apnea are much more likely to fall asleep at the wheel, and the condition is increasingly common as Americans become more obese," said the study's senior author, Stefanos N. Kales, MD, MPH, medical director of Employee and Industrial Medicine at Cambridge Health Alliance, where the study was conducted. "Additionally, we found that drivers who suffer from obstructive sleep apnea frequently underreport symptoms and diagnoses and often do not follow through with sleep study referrals and sleep apnea treatment."
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 a vehicular accident by two- to seven-fold, and is common among truck drivers. Approximately 2.4 - 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.
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. "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," said Dr. Kales.
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 Dr. Kales, who serves as an assistant professor at both Harvard Medical School and Harvard School of Public Health. 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."
"Screening for Obstructive Sleep Apnea During Commercial Driver Medical Examinations published by the Journal of Occupational and Environmental Medicine." March 2009, Vol. 51, Issue 3. Authors: Philip D. Parks, MD, MPH, MOccH; Gerardo Durand, MD; Antonios J. Tsismenakis, MA; Antonio Vela-Bueno, MD; and Stefanos N. Kales, MD, MPH. The study was supported by the Federal Motor Carrier Safety Administration, a research award from the American College of Occupational and Environmental Medicine, and the National Institute for Occupational Safety and Health Education and Research Center.
Cambridge Health Alliance is an innovative, award-winning health system that provides high quality care in Cambridge, Somerville, and Boston's metro-north communities. It includes three hospital campuses, a network of primary care and specialty practices, the Cambridge Public Health Dept., and the Network Health plan. CHA is a Harvard Medical School teaching affiliate and is also affiliated with Harvard School of Public Health, Harvard School of Dental Medicine, and Tufts University School of Medicine. Visit online at www.challiance.org.