Richard Donze, DO, MPH
Senior Vice President of Medical Affairs and Medical Director of the Occupational Health Center and Travel Medicine Program
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 operator (or wannabe) 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 wasn't as long. There were as there still are the usual, traditional “can’t have” disqualifiers such as “loss of a foot, a leg, a hand, or an arm,” use of insulin, history of seizures, etc., many of which are black and white enough to automatically cause affected individuals to put themselves in the “need not apply” category. Over the decades I've never seen anyone missing a whole or part of a limb apply for a DOT medical certificate (maybe a half a ring finger here and there), and only a handful of insulin-requiring diabetics or seizure patients have come looking for waivers.
The disqualifier list is much longer today, and in many cases the route to getting that medical certification card looks more like a bumpy and/or potholed highway. 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. On an opioid for back pain? Sorry, come back when the pain goes away (if ever) or doesn't require anything stronger than ibuprofen or acetaminophen. Which brings us to the question of whether or not to clear someone with an established diagnosis of, or even just risk factors for, obstructive sleep apnea. In case the reason we look at this is not obvious, 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's no arguing with that statistical reality, but plenty of arguing and anger and disagreements and disappointments when trying to apply statistical predictions to individuals who only have risk factors for OSA, but have never been officially tested or diagnosed (at least not yet), and don't have (or don't admit to) snoring, daytime sleepiness, observed pauses in breathing, or a history of falling asleep at the wheel. For these folks, it's a much harder sell to the employer and employee that simply on the basis of these risk factors we can mandate a sleep test and, if positive, adequate treatment, before we can sign the card.
Ever since the DOT exam questionnaire started proactively asking questions about snoring and 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, and one of the sentiments has been that medical examiners are ordering too many sleep tests, which can mean high out-of-pocket costs if insurance doesn't cover it besides 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:
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History of excessive sleepiness while driving.
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History of a crash associated with falling asleep.
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Observed sleeping behind the wheel while operating the vehicle.
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A general category for anyone we think is at "extremely high risk."
As already intimated, some applicants may not be as forthcoming about the disqualifying symptoms and signs, so for someone never diagnosed and never tested and reportedly symptom-free, per the 2016 recommendations we can issue a temporary certificate for 90 days 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; and in the second, it's weight plus other risk factors and/or conditions, as follows.
- Weight range 1: BMI ≥ 40 - Can mandate a sleep test even if no other risk factors present.
- Weight range 2: BMI ≥ 33 and < 40 - Can mandate a sleep test if the higher BMI is accompanied by 3 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 that "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; or
- Male or post-menopausal female.
If the sleep test we have mandated is positive, we would need to see documentation of adequate treatment before issuing a card. If the sleep study is negative despite the presence of risk factors, we would continue to monitor and recommend a re-test if another risk factor were to appear, or the person's weight increased by 10% or more (although if the only additional risk factor is age it would be reasonable to wait three years before re-testing).
The problem for the examiner usually isn't lack of clarity about what to do, but having to deliver the disappointing message. Tell someone who doesn't snore and has never had any observed breathing pauses or fallen asleep at the wheel that just because he's overweight, male, has a neck that measures 18 inches and not enough daylight between his soft palate and his tongue that he will need a sleep study before you can give him a longer-term card, and you will not only have a very unhappy (sometimes hostile) customer in the clinic, you will often get an angry call from a similarly unhappy client contact. Fortunately, clearing drivers previously diagnosed with OSA and currently being treated is fairly straightforward, analogous to the way we certify hypertensives and non-insulin-taking diabetics: 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 ya next year" (since they will henceforth require annual rather than biennial recertification).
It's beyond the scope of this article to discuss all the different treatment options for OSA, but they range from simply losing weight (of course I mean simple to say, not always simple to do) all the way to surgery to either correct the anatomy inside the mouth or in the face to open up the airway, or a bariatric procedure to help with the weight loss. But the usual standard treatment is something called Positive Airway Pressure (or PAP, often with a leading "C" to designate "continuous"). The concept is fairly simple: the affected person sleeps with a mask connected to a small device that delivers air to maintain pressure in the upper airway to keep it from collapsing, thus staying open so the air can travel down the lower airways and into the lungs. Some patients report that the devices are cumbersome and noisy and never get used to them (they may have to try oral appliances as alternatives). Others get past or forget all the inconvenience once they experience consistently better sleep and more daytime energy, often saying they don't know how they ever slept (or lived) without them. But the bottom line is that anyone with OSA who wants to drive a commercial motor vehicle has to do something that results in a better sleep test, thereby reducing the risk of daytime sleepiness.
The medial experts advising the FMCSA repeatedly point out that OSA testing and qualifying/disqualifying criteria represent guidelines, not hard and fast rules, ultimately leaving it up to the certified medical examiner to decide what needs to be done and whether or not the person is medically qualified to drive. But as one of those certified examiners I gotta tell ya--they might as well be laws. Because when it comes down to the question of someone's livelihood vs. public safety, the company's liability and my license, it's usually kind of a no-contest contest. Because if after a careful, thoughtful analysis I were to clear someone the guidelines suggested might not be safe and (God forbid) a bad accident occurred, I could spout my rationale all the way to the local papers and courthouse without engendering much if any sympathy: it would be essentially indefensible.
Is it overkill? Yeah, probably. But we don't know which one it's going to happen to, so we restrict them all. Sometimes we can try to hedge the bet: If someone swears he never gets sleepy and/or his trusty coffee travel mug is always at his side, maybe. It's not a guarantee, but neither is using CPAP, the only kind of bet-hedger the guidelines allow me to use.
It all comes down to risks and predictions. Just because something is more likely doesn't mean it's going to happen, or happen to everyone. Any given individual with OSA may never have a crash related to daytime sleepiness, just as every diabetic on insulin will not drop his blood sugar so low that he passes out and loses control of the vehicle, and not every person with high blood pressure will have a stroke. Those are just population percentages; probabilities. But when I am seeing the individual in my exam room, I have to apply the population probability to that person, to act as if he or she could be the one it happens to. It's the way the preventive medicine/public health mind works: Protect everybody or restrict everybody so that it never happens to the handful it might have otherwise happened to. If we make everyone wear seat belts, then no one will die from an injury a seat belt could have prevented; and if we treat every cut with a tetanus shot, then the rare individual that might have gotten tetanus from a wound will be much less likely to get it. And if I keep every untreated sleep apnea patient off the road, then the one or two who might have nodded off and crashed will never do so. This way, we all sleep better at night.