Richard Donze, DO, MPH
Senior Vice President of Medical Affairs and Medical Director
The Occupational Health Center and Travel Medicine Program at Chester County Hospital
When I performed my first federal Department of Transportation (DOT) physical at The Occupational Health Center in 1993, it was a simpler time in the evolutionary arc of driver medical clearance. The general, overarching question was the same then as now: does this vehicle operator (or soon-to-be operator) have any medical condition(s) and/or take any medication that would make him/her unsafe to operate a commercial motor vehicle? But the list of health issues potentially affecting safety was not as long two decades ago.
Today, there are the traditional disqualifiers such as loss of a foot, a leg, a hand, or an arm; use of insulin; history of seizures; etc. But the disqualifier list is much longer today, and in many cases, the route to getting a medical certification card can be less straightforward.
Sustained blood pressure greater than 140 over 90? Sorry, come back when it's under better control. Passed out from a heart rhythm disturbance? Sorry, come back after the pacemaker insertion. Taking opioids for back pain? Sorry, come back when the pain goes away (if ever) or doesn't require anything stronger than ibuprofen or acetaminophen.
Another common question is whether or not to clear someone with an established diagnosis of, or even just risk factors for, Obstructive Sleep Apnea (OSA). While reason for concern might not be obvious to all, consider this January 2018 statement from the DOT's Federal Motor Carrier Safety Administration (FMCSA):
"Research indicates that driver drowsiness (i.e., fatigue) is a contributing factor in many crashes. . . . One potential cause of driver drowsiness is Obstructive Sleep Apnea (OSA), a sleep disorder. Those who suffer from OSA experience repeated and brief breathing interruptions while they sleep. Due to this disturbed sleep, a major symptom of OSA is excessive daytime sleepiness. . . . Drivers with sleep apnea are seven times more likely to be involved in an automobile accident than those without sleep apnea (National Transportation Safety Board [NTSB], 2003). Drivers with undiagnosed OSA are not receiving proper treatment, leading them to make critical mistakes or even fall asleep while driving due to their fatigue."
So there you have it: People with OSA are more likely to be sleepy during the day and, therefore, more likely to crash. There is no arguing statistical evidence. However, there are plenty of arguments, disagreements, and disappointments when attempting to apply statistical predictions to individuals who only have risk factors for OSA but have never been officially tested or diagnosed. Individuals often have little knowledge of whether or not additional risk indicators, such as snoring, daytime sleepiness, observed pauses in breathing, or a history of falling asleep behind the wheel, are present. For these folks, mandating a sleep test can be a difficult sell, but if positive, adequate treatment can be provided before a signed the card is distributed.
Ever since the DOT exam questionnaire started proactively asking questions about snoring, sleep history, and sleep disorders more than 10 years ago, the regulatory guidance has been dynamic and evolving. Whenever a notice of proposed rulemaking is announced (and with that the possibility of tightening up and clarifying the guidance), parties on all sides of the issue weigh in. One of the sentiments has been that medical examiners order too many sleep tests, which can mean high out-of-pocket costs depending on insurance coverage, keeping too many drivers off the road. As a result, the most recent (August 2016) guidance from the medical experts advising the FMCSA attempted to make this process a little more nuanced, with certain risks only being relatively disqualifying rather than absolute.
However, for someone never diagnosed and never tested, we can disqualify immediately and demand a sleep test for any one of these reasons:
- History of excessive sleepiness while driving
- History of a crash associated with falling asleep
- Observed sleeping behind the wheel while operating the vehicle
- A general category for anyone we think is at "extremely high risk"
There are some applicants who may not be as forthcoming about the disqualifying symptoms and signs. For someone never diagnosed, never tested, and reportedly symptom-free, the 2016 recommendations allow a temporary certificate for 90 days to be issued, pending the results of a sleep test based on the risk associated with being overweight (where weight is expressed as a function of height in the Body Mass Index or BMI). There are two weight ranges. In the first, weight alone is enough of a risk to mandate a test. In the second, weight is considered along with the other risk factors and/or conditions below.
- Weight Range 1: BMI ≥ 40 - Can mandate a sleep test even if no other risk factors are present.
- Weight Range 2: BMI ≥ 33 and < 40 - Can mandate a sleep test if the higher BMI is accompanied by three or more of the following:
- Hypertension (treated or untreated)
- Type 2 diabetes (treated or untreated)
- History of stroke, coronary artery disease, or heart rhythm abnormalities
- Undersized jaw that reduces the size of the airway
- Loud snoring
- Witnessed breathing pauses
- Small or reduced space between the soft palate and the back of your tongue (We use something called "Mallampati Classification" to describe the amount of space where the air needs to move; less space means more potential for OSA, especially if that small space becomes even smaller or disappears when the person lies down.)
- Neck size > 17 inches (male), > 15.5 inches (female)
- Underactive thyroid (untreated)
- Age 42 and above
- Male or post-menopausal female
If the sleep test mandated is positive, we would need to see documentation of adequate treatment before issuing a card. If risk factors are present but the sleep study is negative, we would continue to monitor and advise a retest if another risk factor appeared or if the person's weight increased by 10% or more. If the only additional risk factor is age, it would be reasonable to wait three years before re-testing.
The difficult part for the examiner usually comes when it's time to tell someone who was not previously diagnosed with risk factors that they do not meet the criteria. While not many people enjoy being told they snore or they're overweight, being told those factors are keeping them from receiving their card can result in sever unhappiness. Fortunately, clearing drivers previously diagnosed with OSA and currently being treated is fairly straightforward, that is, document adequate control under a personal physician's watchful eye, then send them happily into the cabs of their trucks with a cheery "see you next year" (since they will henceforth require annual rather than biennial recertification).
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