This issue of the Journal of Occupational and Environmental Medicine (JOEM) includes a separate special supplement on Sleep Apnea and Commercial Motor Vehicle Operators that addresses this important safety and medical risk in commercial motor vehicle (CMV) drivers and provides updated recommendations based on the current literature. Developed by a tri-society Task Force of the American College of Occupational and Environmental Medicine, the American College of Chest Physicians, and the National Sleep Foundation, the final document was approved by all three organizations. The supplement consists of an executive summary1 and original paper2 authored by members of the Task Force.
The topic of sleep apnea in CMV drivers has not been systematically examined in almost a decade. The current US federal medical standard for CMV operators that covers obstructive sleep apnea (OSA) is section 49 CFR 391.41 (b)(5) of the Federal Motor Carrier Safety Regulations (FMCSRs). In this section it states that the CMV driver must have “no established medical history or clinical diagnosis of respiratory dysfunction likely to interfere with the ability to control and drive a commercial motor vehicle safely.” The most recent guidelines from the Federal Motor Carrier Safety Administration (FMCSA) that a commercial driver medical examiner (CDME) has to utilize to evaluate a driver with OSA are two Federal Highway Administration conference reports: a 1991 Conference on Respiratory/Pulmonary Disorders and Commercial Drivers,3 and a 1998 Conference on Neurologic Disorders and Commercial Drivers.4
The 1991 report suggests that drivers should be screened for OSA by asking if they snore and frequently fall asleep during the day. Those with suspected or diagnosed but untreated sleep apnea should not be medically qualified to drive until the diagnosis is eliminated or the condition successfully treated. Once diagnosed, the report recommends that drivers not return to work for one month, and that prior to returning to work, drivers should have either a repeat sleep study showing resolution of the apneas or a normal Multiple Sleep Latency Test (MSLT). Yearly sleep studies or MSLTs are recommended for follow-up.
The 1998 neurologic disorders report recommends that CMV operators with sleep apnea and/or any of the symptoms related to excessive daytime sleepiness not be permitted to operate in interstate commerce. Only surgical treatment is addressed in this report and a three-month wait and laboratory studies (MSLT or polysomnogram) are recommended prior to allowing operators to resume commercial driving.
It wasn’t until 2000, when a new Medical Examination Form went into use that drivers were required to indicate whether they had a sleep disorder, pauses in breathing while asleep, daytime sleepiness, or loud snoring. However, the form provides no additional guidance on diagnosis, treatment, or follow-up.
Given what we have learned over the past decade about the morbidity and mortality associated with OSA and driving, it was felt that this important area must be re-investigated. Numerous studies have found that OSA patients have a 2- to 7-fold increased risk of being involved in at-fault motor vehicle crashes.5 Furthermore, a recent study conducted in Pennsylvania found a higher prevalence of OSA among commercial truck drivers than in the general population.6 (This study found that 17.6% of participants from Philadelphia and its suburbs had mild sleep apnea, another 5.8% had moderate sleep apnea, and an additional 4.7% had severe sleep apnea). Additionally, CMV operators must be held to a higher standard than the general population as they operate larger vehicles which may contain hazardous chemicals, or they may be transporting a large number of passengers. There also is a much higher fatality risk for occupants of the vehicles they hit: trucks weighing more than 10,000 lbs are seven times more likely to be fatal to other motorists as to the truck occupants.7 Adding to this mix is the fact that CMV operators often have economic incentives—they are paid by the mile—to drive further or under unsafe conditions.
The Task Force’s approach to this project was to review existing pertinent literature, medical regulations/guidelines/standards from international organizations, and reports and recommendations from the National Transportation Safety Board (NTSB) and Federal Motor Carrier Safety Administration (FMCSA). Several experts were called upon to review and write sections and a consensus-style meeting was held to review the literature and agree upon recommendations. Experts included occupational medicine specialists and sleep medicine specialists. The result is not an evidence-based guideline, but a consensus document based upon the literature to date as it relates to this topic. It is also important to note that these recommendations are those of this Task Force and do not represent official guidelines. Many of these recommendations are very similar to what exists in other countries including Canada,8 the United Kingdom,9 and Australia,10 all of which were reviewed by this Task Force.
One of the many issues that the Task Force faced was how to measure the effectiveness of a therapy after it was initiated. Several studies were reviewed which looked at a variety of measures of sleepiness including subjective measures such as the Epworth Sleepiness Scale (ESS) and objective measures including the MSLT, the maintenance of wakefulness test (MWT), Oxford Sleep Resistance Test (OSLER), psychomotor vigilance test (PVT), and driving simulators. Subjective measures are often difficult to assess in a population whose livelihood requires them to be awake and vigilant at all times. Motivation to keep their job may outweigh their honesty on subjective scores like an ESS. Moreover, objective measures have not been shown in any of the tests to specifically correlate with fitness to drive or number of crashes. Objective measures are also subject to a number of factors that may vary from one day to the next and one patient to the next including age, circadian rhythm, quantity and quality of prior sleep, medications and psychological factors. Therefore, you will not find any of these specific tests recommended by the Task Force.
Sleep Apnea and Commercial Motor Vehicle Operators provides CDMEs with recommendations for determining when a driver deserves further evaluation for possible sleep apnea based on history and physical examination findings, but is able to continue driving during the evaluation. Recommendations are also provided for when a driver should be taken out of service until the appropriate diagnostic and treatment options can be performed. Furthermore, information is provided on which follow-up treatments should be considered when a CMV operator can return to work after treatment and what type of follow-up is.
Why is this issue important to the readership of JOEM? Sleep disorders largely go unrecognized by both physicians and drivers/patients even though this condition is more common than diabetes. With possibly 28% of all CMV operators suffering from some form of sleep apnea, OSA is a public safety risk that impacts not only drivers and their employers, but everyone with whom they share the road. As occupational physicians, we are responsible for the health and safety of the more than eight million truck and bus drivers on our highways today. However, without additional guidance on OSA diagnosis, treatment, or follow-up, we are often forced to fill in the many existing gaps when evaluating drivers for this safety-sensitive type of work.
It is the hope of the Task Force that this document will not only make physicians aware of the risk factors for and the long-term complications of OSA, but will provide them with the necessary information to identify, and tools to treat, those CMV drivers who are most likely to be involved in a motor vehicle crash contributed to by their sleep apnea. In addition, while these recommendations are directed toward the CMV driver, they are also relevant to others in positions where public safety is an issue, such as those employed in safety-sensitive rail work, transit, maritime, military or nuclear operations.
It is also our expectation that this document will heighten public awareness of the potential hazards and health risks that surround untreated sleep apnea, and that CMV drivers, their employers, and physicians will realize that not only is OSA in and of itself a safety and health hazard, but that it plays a key role in other medical conditions including hypertension, heart failure, and diabetes. With this awareness, we hope that CMV drivers will seek and have rapid access to sleep evaluation and treatment. Diagnosing and treating sleep apnea is an important issue to everyone driving on our highways and especially important to those of us caring for patients that may be CMV operators.
Natalie Hartenbaum, MD, MPH, FACOEM
President and Chief Medical Officer
Nancy Collop, MD, FCCP
Associate Professor of Medicine
Johns Hopkins University
Ilene Rosen, MD, MSCE
Assistant Professor of Medicine
University of Pennsylvania
Barbara Phillips, MD, MSPH, FCCP
Professor of Medicine
University of Kentucky
1. Hartenbaum N, Collop N, Rosen I, et al. Joint Task Force of the American College of Chest Physicians, American College of Occupational and Environmental Medicine, and the National Sleep Foundation. Sleep apnea and commercial motor vehicle operators. Executive summary. J Occup Environ Med.
2. Hartenbaum N, Collop N, Rosen I, et al. Joint Task Force of the American College of Chest Physicians, American College of Occupational and Environmental Medicine, and the National Sleep Foundation. Sleep apnea and commercial motor vehicle operators. J Occup Environ Med.
3. US Department of Transportation, Federal Highway Administration, Office of Motor Carriers. Conference on Respiratory/Pulmonary Disorders and Commercial Drivers. Publication No. FHWA-MC-91-004. Washington: US DOT, 1991.
4. US Department of Transportation, Federal Highway Administration. Conference on Neurologic Disorders and Commercial Drivers. Publication No. FHWA-MC-88-042. Washington: US DOT, Federal Highway Administration, Office of Motor Carriers, 1998.
5. Young T, Blustein J, Finn L, Palta M. Sleep-disordered breathing and motor vehicle accidents in a population-based sample of employed adults. Sleep
6. Pack AI, Dinges D, Maislin G. A study of prevalence of sleep apnea among commercial truck drivers. Federal Motor Carrier Safety Administration, Publication No. DOT-RT-02-030, Washington, DC, 2002.
7. Traffic Safety Facts 2001 [NHTSA]. Publication DOT HS 809 484 (Dec 2002).
8. Canadian Medical Association. Determining Fitness to Drive: A Guide for Physicians, 6th edition. Ottawa, ON: May 2000. www.cma.ca/index.cfm/ci_id/18223/la_id/l.htm
. Accessed August 15, 2006.
9. Drivers Medical Group. For Medical Practitioners: At a Glance Guide to the Current Medical Standards of Fitness to Drive. Swansea, UK: DVLA; 2006. www.dvla.gov.uk/at_a_glance/AAG.pdf
. Accessed August 15, 2006.
10. Austroads. Assessing Fitness to Drive, 3rd Edition. 2003. Austroads Publications No. AP-G56/03. www.austroads.com.au/upload_files/docs/AFTD%202003-F_A-WEBREV1.pdf
. Accessed August 15, 2006.