Buses and Motorcoaches: The Case for Mandatory Sleep Apnea Testing, Part 2

The notion of "screening" driver-candidates for Sleep Apnea screening is not merely unsupportable, it is a delusion. In 2011, 517 truck drivers in Australia were tested for Obstructive Sleep Apnea ("Assessing Sleepiness and Sleep Disorder in Truck Drivers" in SLEEP, 2011). According to an anonymous self-evaluation questionnaire (a "multivariable apnea prediction index, based on self-report measures"), only 12% felt they had it, while roughly 4.4% had tested positive for it. Yet when all of them were tested, 41% more of them had this condition. The testing also found that a full 50% of the study participants were obese, and 49% of them smoked cigarettes. Neither of these parameters are included among the handful of criteria currently employed by either the Federal Motor Carrier Safety Administration's or Federal Railway Administration's "recommended" screening exercise -- although, In fairness, the size-17 male neck (or size 16 female neck) serves as a proxy for obesity. At the same time, as noted below, it also captures plenty of "false positives."

Is there any surprise why derailments and catastrophic motorcoach accidents are so frequent in this country? In 2015, one intercity motorcoach carrier, whose drivers operated the same shifts or pairs-of-shifts for four months at a time, had four of the latter. Regarding derailments, in many European countries, decades go by between derailments.

The Delusion of Screening

One approach almost certain to illustrate the limits of screening would be to test drivers, motormen and pilots involved in catastrophic accidents soon after they occurred. I cannot help but think that testing every single driver, motorman and pilot for OSA, and ensuring an enlightened analysis of the test results -- before this condition contributes to an accident -- would be strongly preferable. Further, testing every vehicle operator would cost only about 2 1/2 times as much as testing only the 40% likely screened for OSA would cost. But it would also cost us a tiny fraction of the value of those vehicle operators, passengers and occasionally others killed or mutilated by drivers who slipped through the cracks of the screening process. So if human lives and human suffering have any reasonable value, mandatory testing of every operator would comprise the "Value-Oriented Approach," while screening would default to "The Cost-Savings Approach." I challenge the FMCSA, FRA or any other organization to characterize universal, mandatory testing as "The Wasteful Approach." And as a forensic expert, I openly dare some defendant responsible for a catastrophic motorcoach accident to testify that its "screening" for OSA certainly captured many or most drivers with OSA, while capturing all of them would not have been "cost-effective." I am hardly the first person to suggest that testing every commercial driver would be "cost-effective: The authors of "An integrated Health-Economic Analysis of Diagnostic and Therapeutic Strategies in the Treatment of Moderate-to-Severe Obstructive Sleep Apnea" argued this in 2011 (Pietzsch J, Garner A, Cipriano L, and Linehan J: Sleep. 2011;34:695-709.).

Another enigma about screening is the near-invisibility of one of its key criteria -- the experience of micro-sleeps. Many if not most OSA sufferers only discover this condition after they crash into something -- assuming they live to tell about it. But even then, most individuals who fall asleep at the wheel do so simply from either the lack of sleep, shift inversion or the "sleep debt" built up from either or both of them. Only four to six percent of the general population has OSA. Yet a far greater percentage of the general population of ordinary drivers simply doze off behind-the-wheel. Even among the 517 commercial drivers tested in the Australian study, while a full 45% of them tested genuinely had OSA, only 12% of them (including those who refused to be tested, even anonymously) reported "excessive daytime sleepiness"). Apparently, where screening is the norm rather than mandatory testing, feeling merely sleepy while driving is acceptable to commercial drivers and their regulatory agencies.

At the other end of the spectrum, one suspects that OSA is less common in individuals who exercise regularly and who are in decent aerobic shape -- a characterization that hardly fits many commercial drivers. Yet the large, heavy athletic drivers in good aerobic shape might be caught in the screening sieve, while plenty of skinny, cigarette smokers who never exercise would slip right through its holes. These examples illustrate why an approach to controlling OSA based on screening criteria alone is so ineffective -- and so risky.

As an interesting footnote, the "screening process" that might subject only a subset of drivers to a night in a sleep lab and at least two visits to a "specialist" -- both of which could lie hours away from a driver's home, and not always covered by the driver's insurance -- is nothing short of "profiling." As a practice, it will last only until the first lawsuit, the first serious media or press disclosure, or its first viral outburst on You-Tube emerges. Were it to emerge following a catastrophic accident covered by a major network or cable new program, the notion of screening would be not only condemned, but ridiculed. Frankly, I am actually surprised that no sensationalist mockery of this folly has yet emerged -- although the FMCSA's and FAA's Advanced Notice of Proposed Rulemaking in support of screening would appear to quality, albeit more quietly.

Cost and Accountability

While the costs of conventional testing for OSA are considerable (including a night in a sleep center and at least two doctors' consultations/evaluations), conventional testing is already obsolete. For several years now, many drivers have been tested by portable take-home Sleep Apnea Monitoring Devices. To make sense from the data these devices produce, one would still need a physician's pre-test analysis to develop a "baseline," and his or her post-test interpretation of the results. Otherwise, a single portable testing machine could be used to test a few hundred drivers a year. So the major cost of OSA testing -- rigging up and renting out a sleep lab -- could and should be a thing of the past. And by engaging clinics to process large numbers of patients' baseline data and post-test results, the costs of otherwise "specialists" would shrink to a fraction of what they currently are.

Considering all these factors, the failure to test every commercial driver (or motorman or pilot) for OSA is not only inexcusable, it is pennywise and pound-foolish. The fact that the FMCSA and FAA are just now debating whether or not screening should become a regulatory requirement is an embarrassment. Like the public transportation community's failure to formally prohibit sleep inversion by commercial drivers, as a regulatory matter, it is symbolic of the marginal attention paid to public safety in our society. More fundamentally, it is a breakdown of common sense.

The Consequence of Misses

Even if only a small percentage of the commercial-vehicle-operating work force with OSA was overlooked by screening, it is interesting to note the likely consequences. Using the slowest-moving of these vehicles as an example, during its driver's single-second-long microsleep, a motorcoach traveling 60 mph will cover more ground than a good NFL-caliber punt. If after awakening from this mini-nap -- assuming that the driver of this vehicle with pneumatic brakes snaps out of it fully alert and detects a problem immediately -- its detection and reaction will consume another 176 feet. And then it will take this vehicle another 280 feet to stop. So when a typical micro-sleeper awakens to find himself or herself in trouble, the vehicle will travel 456 feet before its driver can bring it to a stop -- under "perfect conditions." And, of course, that vehicle would also have traveled 88 additional feet during this single-second microsleep. Perfect conditions means that (a) the driver becomes instantly wide-awake, (b) immediately detects a problem, and (c) immediately slams on the brakes for all he or she is worth. Without these "perfect conditions," the vehicle will travel considerably further before coming to a stop. So, if under these perfect conditions, factoring in a single second of microsleep, a motorcoach full of passengers traveling at 60 mph will have traveled 544 feet before coming to a stop. A lot can happen or change in 544 feet -- even with only a second-long microsleep and perfect conditions coming out of it.

Of course, a driver falling asleep at the wheel on a freeway -- almost certainly with his or her foot on the accelerator -- will likely be traveling even faster. And upon the driver's awakening, his or her vehicle will travel faster, and come to a stop even further away: At 70 mph, if the driver of a motorcoach awakens under perfect conditions, his or her vehicle will have travelled about 205 feet before its brakes even engage -- and it will likely travel another 350 feet or so to come to a stop. And with the single second of microsleep, the vehicle will have traveled more than 655 feet. Again, under "perfect conditions."

A lot can happen with a 43,000-lb. motorcoach during 655 feet of travel -- the majority of which involves no steering or braking. And, again, it will travel only this distance under perfect conditions: The driver awakens completely alert, recognizes the need to stop immediately, and slams on his or her brakes as hard as possible. But if even one of these "perfect conditions" does not exist -- much less all of them (not to mention a longer microsleep), the distance this vehicle will travel before coming to a stop lies far beyond troubling. Would a rational society want to provide this opportunity to even a fraction of its vehicle operators? I hope NBT readers and their industry's regulators feel that we should not. Yet requiring the testing of only those drivers whose handful of symptoms match those of some screening sieve would produce this very opportunity.

Also worth mentioning, failing to even properly apply typical screening criteria to those drivers who meet them would provide this opportunity to even more drivers. A major lawsuit over a catastrophic accident where this actually happened is unfolding as this article is being released. Yet that incident did not necessarily involve a driver with OSA -- because she fell slightly short of the company's screening criteria (among countless other driver and management failures) -- and was never tested. Not surprisingly she was never tested for OSA after the accident.

Challenges to even the Best Solution

Compounding both the limits of screening and its errors (i.e., missing those drivers who actually meet the screening criteria, or those who come perilously close to meeting them) are factors like deregulation, the decades'-long decline in drivers' salaries, and the dynamics of major acquisitions that almost universally translate into lower drivers' salaries and thinner management

Beyond these factors, of course, lie the rarity of coherent fatigue management programs that prevent shift inversion (largely from policies and choices made at the scheduling and driver assignment levels), and the almost complete absence of bio-sensitive driver assignment. So If we properly control even one additional element of this chaos -- mandating the testing of all drivers for OSA -- such a policy would take a huge bite out of the problem. If this approach is a slippery slope toward the implementation of other effective fatigue-mitigation measures, it should hardly warrant a complaint.

The final installment in this three-part series will address the challenges that remain, even if mandatory testing of all drivers were the outcome of the proposed rulemaking. Of course, in its initial form, the ANPRM did not even include the choice of testing all drivers and motormen. Some of the scenarios in the discussion above provide mere illustrations of the problems that remain even if the current rulemaking passes. We will observe real-life manifestation of them, from time to time, in the highly-publicized accounts of the carnage.

As a consequence of all the factors still not addressed, this carnage will not diminish to a minor statistic even when mandatory OSA testing of all drivers is implemented. But until the testing of every single driver for OSA becomes mandatory, and until the remaining challenges are addressed, we will not come close to solving the problems that explode on our public highways, and in our public faces, every time some motorcoach driver falls asleep -- or fades into that fuzzy zone where he or she transitions to some state of semi-sleep, or fades in and out of it. We should hope that our regulatory agencies are not residing in, or drifting in and out of, that zone.