Controversies surrounding the screening of sleep apnea - part 1

If you are a professional in the sleep industry, you likely heard about a report published in the Journal of the American Medical Association at the beginning of this year entitled, “Obstructive Sleep Apnea in Adults: Screening, a US Preventive Services Task Force Recommendation Statement.” These recommendations are based on the foundational evidence report that looked at over 100 evidence-based studies to make determinations on when and where screening is appropriate.

The general conclusion from the report and recommendations reads, “….the current evidence is insufficient to assess the balance of benefits and harms of screening for obstructive sleep apnea (OSA) in asymptomatic adults.” Translated into a more clinically relevant statement might read something like:

We found a lot of gaps in the evidence about OSA. Some of the gaps prevented us from analyzing whether asymptomatic OSA patients or potential OSA patients who do not recognize their symptoms would benefit from preventive screening to determine their need for sleep evaluation and testing. We’re not saying patients with obvious OSA symptoms, or as the best examples patients with cardiovascular disease, should not be screened under any circumstances. But among those patients where there is no obvious expectation for the presence of OSA, then there just is not enough evidence to recommend screening. Moreover, there is also a relatively large gap of evidence on the impact of OSA in various health conditions, even regarding the most important factor of how OSA influences mortality. Without this information on the impact of sleep-disordered breathing on health and wellness and without sufficient evidence on OSA screening, we could not accurately determine the cost-effectiveness of screening for OSA in patients reporting no symptoms or who are unaware of their symptoms. To be clear, however, if your 65 year-old grandmother suffers from hypertension and her family history includes strokes and heart attacks but she denies all sleep breathing symptoms, then by all means her primary care physician would very reasonably consider preventive screening for sleep apnea in your grandmother.

So, what influences do these reports and recommendations have on the field of sleep medicine? How does it actually affect clinical care? OSA already remains under the radar in numerous health industries, thus can we assume these observations will further discourage primary care physicians and dentists from screening for OSA in their patients?

Most of these questions are also unanswerable for reasons we have discussed before. The field of sleep medicine appears to be contracting in certain places (e.g. sleep lab beds) and expanding in others (e.g. home sleep testing), so there may be less availability for testing in the labs. Insurers in particular are trying to push home sleep testing (HST), which theoretically might expand the number of people evaluated for OSA/UARS, but these programs still suffer from loose ends that may result in more patients falling through the cracks, either from a lack of proper diagnosis or from insufficient interactions with sleep professionals to achieve compliance.

Finally, despite all the evidence and headlines that keep filling up a media hungry for stories on the dangers of sleep deprivation and sleep disorders, we still do not see or hear for calls to action from prominent healthcare professionals on the emerging if not ever-present epidemic of OSA. Thus, it is possible this report and the recommendations will have scant impact on sleep-disordered breathing evaluations and treatments with one obvious caveat. Whenever the media gets hold of a story like this one or whenever non-sleep-oriented medical professionals glimpse at the summary of this type of publication, it is possible the only thing that registers is “apparently the big deal being made about OSA isn’t such a big deal, after all,” which could lead primary care physicians to put OSA screening on the backburner.

I find it difficult to believe this report will have great impact on those already integrating sleep referrals into their practices. These doctors, dentists, and mental health professionals are seeing first-hand dramatic improvements in their patients, and this type of report is not going to dissuade them, because their knowledge is well beyond the concepts of screening. To be sure, younger physicians or physicians with little previous exposure to OSA may be inhibited somewhat, but the more they experience first-hand encounters and see the results, this type of report will have small influence on their practice model. Notwithstanding, we must always recognize that insurers have very different motives, and therefore it is conceivable they would use this information to further restrict sleep medical care.

Now, let’s delve more deeply into the reports to see what else was described that may encourage or discourage medical professionals to more seriously consider the potential for OSA in their patients. To start we will examine several of the subjects covered in the Evidence Report and Systematic Review because this information is more comprehensive and is the basis for the Recommendations.

First, it would be interesting to know who wrote this report, and the answer turns out to be mostly MD, MPH physicians, which means they have either a strong interest in public health (MPH = Masters of Public Health) or they work in this field. There were also additional contributors, but I did not recognize any major players from the field of sleep medicine. Such works often proceed in this manner where the authors rely on their ability to rate the value and level of evidence based on certain criteria well applied and adhered to in making broad assessments about any field of medicine. Nonetheless, by using a narrow field of expertise, it would not be unusual to find errors or confusion in how the information is presented and possibly interpreted.

Right off the bat, it is clear the authors either do not understand the relevance of the Respiratory Disturbance Index (RDI) or chose to ignore it. Thus, only the apnea-hypopnea index or AHI is provided regarding the working definition of OSA with no reference to RERAs or flow limitations, which explains the absence of the RDI. This omission is unfortunate because it would have offered a prime opportunity to describe the confusion in the field of sleep medicine itself regarding the facts about so many sleep centers paying little heed to the RDI, numerous sleep professionals erroneously using AHI and RDI interchangeably, and ultimately sleep technologists being discouraged from actually treating the full complement of breathing events within the RDI to provide a more complete treatment regimen.

The next section discusses various screening tools, and in this instance, I am mostly in strong agreement with the findings, which are that these tools are not great. In their conclusion, they wrote, “…there is uncertainty about the accuracy or clinical utility of all potential screening tools.” However, no sleep medicine perspective is offered to clarify how to use these tools in appropriate fashion. For example in our prior work on hypnotic failure in patients seeking treatment at our sleep center, we showed that 90% of chronic insomnia patients suffered from OSA/UARS; and, when using the American Academy of Sleep Medicine screening criteria for PSG in insomniacs and our own sleep center’s approach to screening, we demonstrated high rates of 90% to 100% probability, respectively, for an OSA diagnosis. Yet, when using a common standard in the field to assess these same patients, the Berlin Questionnaire yielded only half of these patients as a positive screen for subsequent sleep testing.

Next, there is a brief section on the wide variability of diagnostic findings when using portable monitors, which of course suggests some problems with reliability and possibly validity. Again, no mention is made of RERA breathing events or the RDI, which is unfortunate, because a few of the monitors are now attempting to supply a measurement for RDI.

One of the main sections elaborated on CPAP treatment with the chief objective being to show that positive airway pressure does effectively decrease the AHI, sleepiness scores and high blood pressure. A point was also made on modest improvements for sleep-related quality of life. In addition to CPAP, the paper covers in depth on the improvements gained with oral appliances (mandibular advancement devices or MAD), airway surgery, and bariatric surgery, all of which provide treatment gains. However, the problem from the point of view of the authors’ was that insufficient high level evidence provided consistent or valid findings for how downstream OSA affects bigger issues like cardiovascular disease or mortality.

I will not argue against their findings, because they are using accepted standards for levels of evidence, so I will defer to their systematic review of the data. However, there is an old saying in medicine, “it often takes time for science to catch up with common sense.” And, the overwhelming practical or common sense thinking about sleep medicine is provided by the actions of cardiologists all over the world who are routinely referring cardiac patients for sleep testing. Some of the most common areas of attention are among patients with congestive heart failure, arrhythmias such as atrial fibrillation and poorly controlled hypertension. And, what these referrals mean with reasonably high probability is that the “marketplace” is demonstrating to cardiologists their patients are benefitting from pursuing OSA treatment. While there is always the possibility something else is going on to explain these health improvements—something like these patients really needed more oxygen not PAP devices—given the complexity of sleep disorders and their obvious impact on brain and heart function, it stands to reason if your normalize airflow and reconsolidate sleep (brain EEG), then good things might be expected to follow. And, if you take the easiest downstream effect, we would measure whether decreasing sleepiness makes patients better and safer drivers of motor vehicles. Thus, when patients come back to clinic after their early trials with PAP and report no longer falling asleep at traffic lights, common sense dictates that benefits and possible cost-savings were achieved by regularly use PAP. Conceivably, not enough research has been conducted to provide high-level evidence here so the authors feel compelled to interpret the data accordingly, but they are inaccurate in their understanding of real world clinical sleep medicine.

The second to last section briefly describes side effects occurring from OSA treatments. Obviously, the use of PAP, MAD, and conservative weight loss strategies generate far fewer “harms” (their term) than invasive procedures such as bariatric and airway surgeries. However, I was disappointed this section did not include harm done to individuals who fail treatment and then drop out of care for months or years. Instead, the focus was on the usual PAP-related suspects of oral or nasal dryness, eye or skin irritation, rash, epistaxis, and pain. Remarkably, they failed to mention aerophagia (air swallowing), the worsening of sleep in as many as one-third of patients due to poor adaptation, and most importantly, the traumatizing effects of CPAP when claustrophobic and panic reactions occur in psychiatric patients. By omitting these side effects, the authors missed salient points on why PAP therapy has poor adherence rates in select populations, a clinically relevant consideration for decision-making.

In part 2 of this post, we’ll look at the final Discussion from the authors where they speak to how they arrived at their conclusions. Then we’ll move onto the Recommendations report. Stay tuned.

About the author

Image of Dr Barry Krakow, sleep physician and HST America blog contributor.

Dr Barry Krakow’s 27 years of sleep research have focused on the complex relationship between physiological and psychological sleep disorders. Dr. Krakow started in sleep research in 1988 and helped pioneer innovative therapies for chronic nightmare patients. Since 1995, he has practiced sleep medicine full-time and currently operates Maimonides Sleep Arts & Sciences, Ltd., a private sleep medical center specializing in the treatment of sleep disorders such as insomnia and sleep apnea in mental health patients. He is also principal investigator of the Sleep & Human Health Institute, a non-profit research center that focuses on the complex interplay between physiological and psychological sleep disorders.

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