The Case for Mandatory Sleep Apnea Testing, Part 2: The Weaknesses of Screening

Nothing could better illustrate the folly of OSA screening than the fact that my own OSA status literally changed between my authorship of Part 1 of this series and this installment. In the hope of finding an honest and competent sleep doctor willing to tweak my OSA treatment machine, the excellent specialist I finally saw determined that I did not have OSA at all. Instead, the heavy medication I take to merely fall asleep was effectively closing my airways such that the results of the study I underwent in a sleep lab suggested I had OSA but did not – consistent with my absence of any OSA screening criteria. In other words, screening would not have suggested I should be tested, while testing itself produced a “false positive.” Of course, with an initial positive interpretation of the study data, the process of getting my machine adjusted gave a better doctor a chance to correctly interpret the test results. So after days wasted, and roughly $1000 spent on unneeded equipment, I am back precisely where I started from and where I would have been if screening criteria had been applied to me. 

One could oversimplify the meaning of my experiences to conclude that the screening was correct all along: I did not have classical OSA symptoms and, as it turned out, I do not have OSA. However, had I not been tested, I would not have discovered that my airways were being closed during my sleep (depriving me of oxygen just as if I had had OSA). And I would have been deprived of the opportunity to find a direction to address my sleep problems. In simple terms, screening is nothing but a challenging sieve. Testing, and its interpretation, are what leads to the diagnosis. 

Personally, this very experience is enough to convince me that screening represents nothing a sloppy guess, while only testing produces evidence. But NBT readers should not draw conclusions from a single individual’s faux-OSA experiences. The argument for the mandatory testing of every pilot, motorman and professional driver should proceed further. 

The Delusion of Screening

My own experiences with screening does not remotely comprise a “random sample.‘’ Yet when the 45% of drivers in the Australian study who actually possessed OSA were identified by a “multivariable apnea prediction index, based on self-report measures,” this index identified only a small number of them. Even the far-better criteria employed by the FAA and FRA to screen pilots and motormen did not include either obesity (although, in fairness, neck size served as a reasonable proxy for it) or smoking. Yet the Australian study found that a full 50% of the study participants were obese, and 49% of them smoked cigarettes. 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. Yet I cannot help but think that testing every single driver, motorman and pilot for OSA, and ensuring an enlightened analysis of the test results, would be strongly preferable. It would cost about 2 1/2 times as much as testing only those 40% likely screened for OSA would cost. But it would also cost us a tiny fraction of the vehicle operators, passengers and occasionally others killed or mutilated. Mandatory testing of every operator would have to live with the stigma of being “The Value-Oriented Approach,” while screening would default to “The Cost-Savings Approach.” I challenge the FMCSA, FRA or any other organization or individual to characterize universal, mandatory testing as “The Wasteful Approach.” 

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 discover it. But even then, most individuals who fall asleep at the wheel do so simply from the lack of sleep, or shift inversion. Only four to six percent of the general population has OSA. Yet a far greater percentage of the general population of drivers has simply dozed off behind-the-wheel. 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 it. These examples illustrate why an approach to controlling OSA based on screening criteria alone is so risky, and so unreasonable. As noted, it is not even cost-effective in a society that places any value on human life and health, much less when considering even the economic costs associated with the often lifetime of treatment needed for those serious disabled by a catastrophic accident.

As an interesting footnote, the “screening process” that would subject: some drivers to a night in a sleep lab and at least two visits to a “specialist” – both of which could be hours away from the 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. Were it to emerge following a catastrophic accident covered by HOB’s VICE, the notion of screening would be not only condemned, but ridiculed. Frankly, I am actually surprised that no revelation of this folly has not yet emerged. 

The Consequences of Misses

Even if only a small percentage of the operator 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 a single-second-long microsleep, a motorcoach traveling 60 mph will cover more ground than a good NFL-caliber punt. If after awakening from this nap, assuming that the driver of this vehicle with pneumatic brakes 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. Factoring in the single second of the microsleep, that vehicle will have traveled 544 feet. 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 somewhat faster. At 70 mph, a motorcoach 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. A lot can happen with a 43,000-lb. motorcoach during 643 feet of travel – the majority of which involves no steering or braking. And travel only at this distance if the driver recognizes the need to stop immediately after awakening. Would a rational society want to provide this opportunity to even a fraction of its vehicle operators? I hope NBT readers who feel that the U5. is such a society, as well as that society’s regulators, feel that we should not. Yet requiring the testing of only those drivers whose handful of symptoms match those of the screening sieve would produce these very opportunities. 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 – among scores of other driver and management failures – is unfolding as this article is being released. 

Compounding both the limits of screening and its errors (i.e., missing those drivers who actually meet the screening criteria) 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 – since most elements of a transportation system cost all competitors pretty much the same, and reducing the quantity and pay of driver and management are largely the only factors that the acquisition partner can control to make itself more competitive (and the acquisition more successful). Beyond this, of course, are 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. If we can 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 other effective measures, this trend should hardly warrant a complaint. 

Challenges to Even the Best Solution

The final installment in this three-part series will address the many challenges that remain, even if mandatory testing of all drivers is the outcome of the proposed rulemaking. As I suspect it will not be particularly since it was not even raised as a possible approach – the challenges are even greater. Some of the examples above provide mere illustrations. We will observe real-life versions of them, from time to time, in the highly-publicized accounts of the carnage. 

This carnage will not diminish to a minor statistic even when mandatory OSA testing of all drivers is implemented. That is because of other causes of driver fatigue not yet addressed. But until the testing of all drivers for OSA becomes mandatory, and until the remaining challenges with it are addressed, we will not become even close to solving the problems that explode in our public faces every time some motorcoach driver falls asleep at the wheel ~- or fades into that fuzzy zone where he or she transitions to some State of sleep, or fades in and out of it – if only with a tiny micro-sleep here and there. 

Publications: National Bus Trader.