Toward an Integrated Care Model for Obstructive Sleep Apnea
How do you define CPAP failure? The CMS guidelines set the generally accepted compliance threshold at 4hr/night on 70% of nights. What about Oral Appliance Therapy (OAT) failure? Here the definition gets more fuzzy. In a 2014 review, Sutherland et al. identified several alternative success criteria used by clinicians and researchers: a treatment AHI <5 (complete resolution of OSA) or <10 (very mild disease), or a 50% reduction from baseline AHI. In reality, each of these thresholds circumscribes only half of the problem: after all we are not treating numbers, but health outcomes, and the recently introduced concept of Mean Disease Alleviation (MDA) points to the fact that the higher compliance rate of OAT tends to balance its lower efficacy, resulting in a remarkable outcomes equivalence (Phillips et al. 2013; Roy 2014; Sutherland et al., 2014; Vanderveken 2015).
Nevertheless, the concept of “failure” haunts the field of sleep medicine – from sleep physicians and DME suppliers who worry about the patient abandoning CPAP therapy after trying multiple mask interfaces and pressure settings, to the dentist who knows that only approximately half of oral appliance users are going to fully respond to therapy, depending on one’s definition of success (Sutherland et al. 2014) and ultimately to the patients themselves, who wonder whether failing to achieve the target AHI with an oral appliance means they will be forced to give up on this option and turn (or return) to CPAP, contemplate surgical solutions, or resign themselves to living with untreated apnea – which unfortunately is not an uncommon outcome.
But knowing what we currently know about combination therapy options for sleep apnea, is this success-failure dichotomy the best way to frame the issue to our patients? Is it the most constructive way to formulate a treatment plan with the patient’s other healthcare providers – the much-touted multidisciplinary approach that is the cornerstone for successful long term management of sleep disordered breathing? Considering that only 10-20% of the estimated 25 million Americans with OSA are currently diagnosed, that approximately 15-30% of those diagnosed patients refuse CPAP while another 20-40% discontinue CPAP after 3 months (Ravesloot 2011), yet only a very small fraction of OSA patients pursue treatment with oral appliance therapy or surgery, it is obvious that the vast majority are unable to successfully navigate the current system and receive adequate treatment. Is there a better, integrated way to screen, test, counsel and follow up OSA patients as they move through our healthcare network?
Over the past few years, combination therapy has emerged as a still exploratory, yet tremendously promising and versatile concept in the treatment of sleep apnea. Multiple studies show a significant positive effect on AHI with weight loss (Peppard 2000, Smith et al 1985), which may allow an OSA patient to tolerate CPAP at a lower pressure (Vanderveken 2015). Positional therapy studies have consistently demonstrated that AHI values can move from the moderate and severe ranges to mild scores when using a sleep position trainer, which could lead to a successful treatment when combined with oral appliance therapy (Heinzer et al 2012, Lee et al 2012, Dieltjens et al. 2014, Levendowski 2014). Oropharyngeal exercises designed to improve muscle tonus and functionality have been shown to considerably reduce AHI, improve snoring frequency, daytime sleepiness and sleep quality score (Guimaraes et al 2009, Ieto et al 2015). Most significantly, the concomitant use of mandibular repositioning devices has been shown to provide a very successful rescue approach in previous CPAP failure cases, as the lower pressure requirements result in a much more acceptable patient experience (Sanders 2015, el Sohl et al. 2011). In light of these results, Olivier Vanderveken’s 2015 JDSM editorial seems fully justified as it raises a fundamental question: should combination therapy remain relegated to the status of taboo, or should it become the new standard of care?
Such a paradigm shift would have significant implications, because the new framework would allow us to define clear roles for everyone involved in the management process, from patient to the primary care team, to the specialists treating his/her pulmonary or cardiometabolic problems. While we are familiar with the notion that OSA is a progressive disease which must be monitored with long-term follow-ups and re-evaluations as patients age and gain or lose weight, an equally important conversation should take place at the start about the multiple factors affecting the success of various OSA treatments and their short- to intermediate-term management. If OSA treatment is not presented as a “win or lose” alternative but as a dynamic process in which the patient can play an active role, with clearly defined and achievable intermediate clinical goals, then perhaps the very common desire to transition from CPAP to OAT or an even more conservative positional therapy could be used as an incentive to motivate lifestyle changes, as the patient works through a matrix of modifiable risk factors and little by little gets closer to an effective OAT solution. While it is true that with comparable adherence rates CPAP tends to provide the best and most predictable improvement in AHI values and that such “weaning off” CPAP may not be achievable in a significant percentage of cases, depending on the patient’s phenotype, it is also essential to recognize the importance of educating patients about the modifiable risk factors and adjunctive approaches available to them, as each component of the therapeutic equation (weight loss, reducing nasal resistance, strengthening oropharyngeal muscle tone, positional therapy, biomimetic DNA appliance therapy as well as surgery and even proper sleep hygiene) represents an additional contribution to the success of the treatment, with or without CPAP.
When and for whom should hybrid therapy be introduced as an alternative? The concept of Mean AHI/Mean Disease Alleviation (Ravensloot 2011, Sutherland et al 2014, Vanderveken 2015), in combination with objective OA adherence monitors like DentiTrac (Braebon) will allow us, in principle, to set targets for overall outcomes and determine whether an individual patient is doing better on CPAP, combination or oral appliance therapy, taking into account both the efficacy of the treatment and the amount of time that the patient is able to tolerate the treatment each night. While no one disputes the superior benefits of CPAP that is worn nightly for the full duration of the sleep period, in patients who are marginally compliant, refuse or fail CPAP per the current CMS benchmark, an oral appliance is the typical second line of treatment, unless surgery is indicated for obvious craniofacial abnormalities. Since phenotyping plays such an important role in patient response to oral appliance therapy, the patient should understand from the start what the OAT statistics (probability of an optimal response) are and that where a suboptimal result is achieved, hybrid therapy using lower-pressure CPAP or compliance-monitoring positional training devices such as Night Shift (Advanced Brain Monitoring) should be immediately introduced, calibrating these multi-modal interventions until the target MDA is achieved, possibly in combination with weight loss, oropharyngeal exercises and ENT referral where nasal airway resistance is suspected. Thus framed, the OAT alternative is no longer defined by “success or failure”, but by a customized combination of factors that can be modified to achieve an acceptable therapeutic response, and by the length of time required to reach it. Critical to this approach would be establishing a close follow-up schedule for the first year of treatment, so that any adherence problems are identified and addressed in a timely manner by the interdisciplinary team managing that patient.
At the same time, it is important to realize that obstructive sleep apnea does not exist in isolation, but is pathophysiologically connected to other systemic inflammatory risk factors, such as periodontal disease (see Billings, 2015). Weight loss becomes more difficult to achieve in the presence of sleep disordered breathing, and insulin resistance is markedly affected by both sleep apnea and periodontal inflammation – to mention just a few of the mutually reinforcing mechanisms which make cardiometabolic conditions so challenging to control. Therefore, developing a common matrix of goals and clinical parameters (Table 1) could provide patients and their physicians with a road map in the management of these interconnected chronic diseases. What if instead of struggling independently, providers were able to share this common work sheet, entering the results of various lab tests and clinical findings into a common EHR Systemic Inflammatory Risk Matrix?
Beginning with primary care sleep apnea screening and referral guidelines in high-risk populations (such as patients presenting with diabetes, hypertension, or a history of heart disease or stroke, per 2009 AASM guidelines – Force 2009), a shared EHR matrix would allow each clinician to see an instant snapshot of where the patient is in relation to the current goals, point out the factors that are well managed versus the ones that need improved compliance, and reinforce those short-term steps required to improve both apnea and systemic health outcomes. For example, an increase in hsCRP or HbA1c on a routine PCP visit could trigger a matrix check for the latest CPAP or OAT compliance numbers, periodontal status (bleeding index or semi-quantitative biofilm reports such as MyPerioPath from OralDNA Labs), weight changes, or even prompt questions about a history of recent nasal allergies. Depending on the individual patient history and changes in matrix values, a PCP might recommend dietary counseling or short-term manageable weight loss goals; a follow-up with their dentist to discuss OralDNA testing and adjunctive methods (such as Perio Protect) to reduce the impact of periodontal biofilm on systemic inflammation and glycemic control; or temporary nasal decongestants/steroids to deal with the effect of seasonal allergies and their impact on CPAP/OAT efficacy. Because patients don’t routinely see their sleep physician every few months, having multiple providers keep tabs on the number of parameters affecting the systemic inflammatory equation and reinforce the same message may transform the patchwork of uncoordinated PCP and specialist consultations into a more coherent program of manageable steps, maximizing the benefits of shared EHR to help the patient correct course more frequently and keep tighter control over the desired health outcomes.
Equally important, built-in algorithms could take into account clinical value inputs and dates to highlight recommended tests, missed follow-ups, abnormal results and suboptimal compliance: a shared EHR matrix to which all providers have access, from the referring PCP or dentist to the sleep physician prescribing CPAP to the CPAP supplier, will quickly allow the PCP on a routine visit to document lack of CPAP compliance, triggering the request for a follow up consultation with the sleep physician and dentist to discuss Oral Appliance or Combination Therapy. A similar request could also be initiated by a CPAP supplier anticipating case failure and trying to rescue it with combination therapy before the patient drops out of the system. Given that approximately 20% of patients who are advised by their PCP to get a sleep test do not pursue it (Sleep Review, 2014) and that a significant percentage of required post-treatment sleep tests are never completed, that lack of follow-through would also trigger a recurrent alert and reminders from different providers on all subsequent visits until the test was completed.
When clinicians and patients establish a common, standardized flow chart of objective tests and biomarkers, coordinated follow-up becomes tighter and overall health outcomes such as blood pressure or measures of glycemic and weight control can be more readily managed as part of the overall therapeutic equation. Such an integrated, dynamic treatment matrix may be an unrealistic proposal at this point, however our healthcare system is rapidly evolving, along with our treatment paradigms. As the focus shifts toward outcomes-based medicine, the time may come when evaluation and effective therapy for sleep apnea becomes as routine as checking blood pressure or glycemic status, and a treatment prescription may involve not one but multiple specialists.
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