An expert reviews the literature on ACPAP adherence and discusses real-world approaches to promoting device usage in obstructive sleep apnea patients who take this increasingly common route.

Continuous positive airway pressure (CPAP) remains the gold standard therapy for obstructive sleep apnea (OSA).1 CPAP has traditionally been initiated by an attended in-lab polysomnography (PSG) with manual adjustment of pressure by a sleep technician.2 This process involves time spent prior to the PSG reviewing OSA and CPAP as a treatment, a formal mask fitting, and then ongoing adjustments and reassurance over the course of the night.

Goals of the in-lab titration have always included helping the patient to acclimate to CPAP therapy and providing an experience that will hopefully encourage long-term use. Despite these efforts, up to 8% to 15% may decline CPAP therapy up front3 (as high as 60% in certain populations)4 and, of those accepting CPAP, as many as 50% will not remain “adherent” over the long term.5 Optimal adherence has long been defined as 4 hours of use per night for 70% of nights,6 and even the Centers for Medicare and Medicaid Services (CMS) recently embraced this as its standard for acceptable adherence.7 However, data suggest there may be additional benefits from more than 4 hours of CPAP use per night with continued improvements in the Multiple Sleep Latency Test and Functional Outcomes of Sleep Questionnaire with each incremental hour of CPAP use up to 6 and 7.5 hours per night, respectively.8 As such, it seems warranted to invest significant effort into maximizing our patients’ CPAP use for their health and well-being. If that is not incentive enough, CMS has instituted a practice of no longer reimbursing for CPAP if patients fail to meet its standard at 3 months.7

A significant body of literature now supports a pathway of home testing for OSA followed by in-home initiation of CPAP therapy via autoadjusting CPAP devices (ACPAP) in appropriate patients. This approach bypasses the in-lab sleep study, and results in the patient’s first nighttime experience with CPAP at home without on-site support. This has raised concerns about whether this could influence acceptance of and adherence to CPAP therapy, potentially leading to more treatment failures. This is a valid concern as CPAP use in the first 3 days has been shown to predict longer term use.9 This article will review methods that have been shown to improve CPAP adherence, compare how initiating CPAP therapy via a home ACPAP route stacks up against in-lab titrations, and then discuss how these approaches can be combined to ensure success for your patients.

Basic CPAP Adherence Maneuvers

There is a wide range of interventions to improve adherence to CPAP therapy, and these can be placed into the categories of technological adjustments, behavioral (including educational and supportive) interventions, and management of CPAP-related side effects.10 Technological options for pressure modalities have included the use of ACPAP, bilevel pressure devices, and expiratory pressure relief.11 By and large, these PAP alternatives have not consistently been shown to improve adherence to PAP therapy,11 although interestingly ACPAP increased CPAP use by 0.21 and 0.23 hours per night in two recent meta-analyses, a finding that was statistically significant in both but is of questionable clinical significance.11,12 Heated humidification is another advance that was hoped to improve adherence, though findings in this regard are equivocal.11

Included under the heading of behavioral approaches are educational interventions, supportive actions, and behavioral therapy. Educational interventions can range from written handouts and videos to group sessions and one-on-one sessions. They may last from 15 minutes to up to 4 hours and have been shown to increase PAP usage by about 0.60 hours per night as well as lead to 13% more patients using PAP for longer than 4 hours per night, both statistically significant findings.3 However, the quality of the evidence supporting educational interventions is considered only low to moderate. Supportive interventions may be as simple as a follow-up phone call by qualified personnel and computer-assisted monitoring and trouble-shooting to more complicated maneuvers such as comprehensive follow-up home visits. Reviewing PAP download data and early follow-up with a sleep practitioner are also considered supportive care. These types of interventions may increase PAP adherence by 0.83 hours per night and increase those crossing the 4 hours of use per night threshold by 16%. Again both of these findings are statistically significant, though the quality of evidence is low.3 Behavioral therapies most commonly used include cognitive behavioral therapy and motivational enhancement therapy. These therapies must be delivered by someone with training in these techniques and have been found to increase PAP use by up to 1.4 hours per night as well as result in a 19% increase in the number of patients exceeding the 4 hours of use per night standard. However, the quality of these studies is rated as low and there is significant variability in the individual findings.3

Coupled with early follow-up and supportive care is management of potential side effects from PAP therapy. This includes pressure-related adverse effects (for example, congestion, dryness, aerophagia, and leaks), interface-related adverse effects (eg, irritation and sores), and psychological effects (eg, anxiety and claustrophobia). While beyond the scope of this paper, there are a number of solutions for each of these and addressing these problems should, in theory and in practice, improve adherence.10

ACPAP Adherence vs In-lab Titration Data

Over the last decade, there have been a number of well-designed controlled trials demonstrating that regardless of which method is used to initiate PAP therapy—whether via an attended in-lab titration PSG or starting with ACPAP at home—adherence to PAP therapy appears equivalent at 4 to 12 weeks.13-20 In studies in which patients started CPAP via the ACPAP route, the majority used ACPAP for a single night at home before selecting the best pressure for fixed pressure CPAP (based on the ACPAP download), with which the patients were subsequently treated. There were two notable exceptions in which patients utilized ACPAP at home for either 4 to 5 nights18 or 5 to 7 nights20 before a fixed pressure was determined. Of interest, these were also the only two studies that found significantly better adherence (not just equivalence) to CPAP therapy at 12 weeks in the patients who started in the ACPAP arm as compared to those in the in-lab titration arm.

There are some caveats to consider when examining this body of literature. First, almost all the studies used highly select patient populations. Patients had to be at “high risk” for OSA prior to enrollment and were generally free of any significant cardiac or pulmonary disease due to concerns regarding the use of ACPAP therapy in patients with these conditions. Second, all studies utilized educational and supportive protocols for patients in both arms. While this varied somewhat by study, most provided video instruction and written materials and/or in-person education and instruction regarding OSA and the use of CPAP. These sessions typically lasted 30 to 45 minutes. Once patients were on fixed CPAP, all studies provided participants with phone follow-up within 1 to 2 weeks and usually a visit with a sleep practitioner within 4 to 6 weeks. None of the studies utilized behavioral therapies. Third, the majority of studies utilized trained personnel for mask fittings, trouble-shooting, and follow-up. This may be particularly important for sleep centers that do not control the quality of care delivered by their designated PAP provider (for example, a home care company). And finally, the longest studies looked at adherence only out to 3 months.

Getting Real-World Results

It’s one thing to show promising results in a controlled study environment, but it’s another to put it into practice and obtain the same outcomes. However, it should be encouraging that two of the aforementioned studies attempted to mimic more “real world” conditions and still yielded the same results.18,19

The first step in making a home ACPAP pathway work is to ensure that the correct patients are considered. Patients should have an established diagnosis of OSA and should not have comorbidities that might put them at risk for the development of central apnea or hypoventilation during a trial of ACPAP (for example, significant or uncontrolled heart failure, moderate to severe COPD, or clinically significant neuromuscular disease).21

The next step is to have a standardized protocol for patient education regarding OSA and CPAP therapy, as well as a mask fitting and practical CPAP instructions prior to trialing ACPAP at home. The duration and intensity may depend on resources available to the sleep center, and a center may need to consider additional daytime support personnel. However, it’s important to realize that this is key to the patient’s initial experience with PAP and can set the tone for long-term adherence. Patients should also be provided with additional resources for self-education as well as an on-call number in case problems or questions arise on their first night(s) of therapy. Assuming the patient will not remain on ACPAP indefinitely, a PAP download with inspection of the results and determination of a fixed CPAP pressure setting will be needed. Communication with the patient at this point offers an opportunity for trouble-shooting, support, and reassurance.

And finally, close clinical follow-up and support after the initiation of therapy is a must as early use of PAP therapy predicts long-term adherence. This is where sleep centers that do not do their own durable medical equipment (DME) supply will need to work in collaboration with, and rely upon, home healthcare DME providers. However, sleep centers should certainly ensure follow-up of patients with a sleep practitioner within 4 to 6 weeks of the start of PAP therapy.

It is possible to make a program of home initiation of PAP therapy work in the real world, though it may require some reallocation of resources and creativity on the part of sleep centers. The incentive of better health for our patients is all that’s needed, but now that adherence-driven reimbursement has been implemented, the stakes have risen for all involved.

Dennis Auckley, MD, is director of the Center for Sleep Medicine at MetroHealth Medical Center in Cleveland and associate professor of medicine at Case Western Reserve University.


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