Using Home Testing Devices for the Diagnosis of Sleep Apnea. What Can We Learn From the VA? – David Barone

Sleep Apnea at the VA
The government-funded Veteran Health Administration (VA) system is responsible for managing the health of approximately 6 million people. While the prevalence of obstructive sleep apnea (OSA) within the general adult population is estimated at 4% for males and 2% for females, the prevalence within the VA system, with its larger number of middle-aged, elderly and male patients, could be four times that of its occurrence in the general U.S. population.1

In recent years, the VA system was subject to continuous cost pressures, coinciding with the growing demand for services to veterans, who are getting older and sicker. Limited capacity of beds and/or personnel required many patients suspected of OSA, a disorder considered sometimes inappropriately as a non life-threatening condition, to wait for a sleep study six to twelve months, and at times, even longer. Paradoxically, as the proliferation of hospital-based and standalone sleep labs has reduced the waiting time for sleep studies around the U.S. from months to a few weeks,2 access to a sleep study for VA patients in many regions continued to deteriorate. These delays are especially worrisome, as many of the diagnosed patients handled by this system suffer from significant co-morbidities adversely affected by OSA, including hypertension, obesity, diabetes mellitus, cardiovascular disease (including MI and angina), heart failure and cerebrovascular accidents.3

One of the options available to providers of sleep services attempting to improve access to diagnostic sleep tests is to use portable devices (also known as ‘home sleep testing’ or ‘ambulatory test devices’). Portable devices do not require specialized facilities, and in most instances can operate with less technical resources compared to Polysomnography (PSG) studies. While their adoption in the U.S. has been constraint by third-party payers’ limited coverage policies, a growing number of VA centers, free to select technologies based on their merit and evidence rather than insurance mandates, have accepted portable monitoring as a clinically appropriate testing modality for many of their patients suspected of OSA. A number of VA centers that did not have any in-house diagnostic capabilities and referred all their patients to other facilities, typically at additional expense to the system, have added portable testing to address the needs of many of their patients while reducing dependency on other VA or non-VA centers. Other centers have developed protocols using both portable testing and in-lab PSG, allowing better utilization of resources and services based on patients’ indications and needs, and by doing so, increased number of patients treated and realized enhanced outcomes without incurring higher expenses. Use of Portable Systems to Manage OSA

A number of VA centers that did not have any in-house diagnostic capabilities and referred all their patients to other facilities, typically at additional expense to the system, have added portable testing to address the needs of many of their patients while reducing dependency on other VA or non-VA centers. Other centers have developed protocols using both portable testing and in-lab PSG, allowing better utilization of resources and services based on patients’ indications and needs, and by doing so, increased number of patients treated and realized enhanced outcomes without incurring higher expenses.

Use of Portable Systems to Manage OSA
The primary means of confirming sleep apnea, following a review of medical history, symptoms and a physical exam, is to conduct a sleep study. Polysomnography is the most commonly practiced sleep test today, indicated for the diagnosis of nocturnal breathing disorders as well as neurological disorders such as narcolepsy, Periodic Leg Movements and parasomnia. A number of studies published in recent years have reported on the efficacy of a new generation of portable devices in supporting clinically accurate diagnosis of OSA and their ability to offer an alternative to PSG. While such devices measure a fewer number of parameters compared to PSG, they do provide the information required to establish an accurate diagnosis of OSA, determine the severity of the disease and correspondingly, support treatment decisions. Growing awareness of the impact of OSA on other morbidities and on patients quality of life led to calls by the Institute of Medicine,4 the National Sleep Foundation5 and other for expanding the use of all assessment methods supported by scientific evidence. Such devices can augment PSG in numerous situations in which PSG is not readily available or practical, such as conducting tests on hospitalized patients, evaluating patients scheduled for general anesthesia, assessing treatment efficacies, or simply responding to situations in which a quick diagnosis is required. Portable testing devices also enable clinicians to offer an alternative venue to physically challenged patients who cannot easily reach or stay in a sleep lab, those residing too far from a sleep lab, or the many patients that simply refuse an in-lab PSG, but accept the discrete home study.6

Growing awareness of the impact of OSA on other morbidities and on patients quality of life led to calls by the Institute of Medicine,4 the National Sleep Foundation5 and other for expanding the use of all assessment methods supported by scientific evidence. Such devices can augment PSG in numerous situations in which PSG is not readily available or practical, such as conducting tests on hospitalized patients, evaluating patients scheduled for general anesthesia, assessing treatment efficacies, or simply responding to situations in which a quick diagnosis is required. Portable testing

As is often the case with technologies that offer new methodo­logies for managing patients with specific medical conditions, the optimal use of portable devices for ruling-out or confirming OSA is subject to debates by practitioners and researchers of sleep disorders. Yet, most agree that many sleep apnea patients can be diagnosed with less than a full PSG montage, especially if trained physicians oversee such studies. Indicative of such approach are the guidelines published by the Minnesota-based Institute for Clinical Systems Improvement (ICSI),7 which state that “employment of portable monitoring as a second-best option is not likely to result in harm to patients with a high pretest probability of OSAHS, and may result in less risk than leaving the condition undiagnosed.”

One of the new portable systems already in use in a number of VA centers is the Watch-PAT, cleared by the FDA for the diagnosis of OSA in an unattended-setting. The Watch-PAT obtains the information required to determine a diagnosis of OSA from two finger-mounted probes attached to a small wrist-mounted device, which also incorporates actigraphy. The Watch-PAT does not require nasal cannulae to record interruptions to airflow, and instead, identifies such events by monitoring changes in peripheral vascular flow caused by the autonomous nervous system, a measure reflecting

Valuable Experience at the VA
This article is not intended to offer a comprehensive review of the use of portable testing devices within the VA system, but rather, summarize the experiences gained by two regional VA medical centers, as reported to the author. The cases below illustrate how home studies, when used appropriately and rationally together with PSG, contribute to enhanced level of care in for a population characterized by its higher morbidity, including a higher than normal prevalence of sleep apnea.

Example 1: A VA medical center serving a large and mostly rural area, has experienced patient demand that could easily support an in-house sleep lab. However, the center’s administration has elected in the past to operate only a sleep clinic on its premise and refer patients requiring a sleep study to a local, non-VA sleep lab, located in one of the large regional medical centers. Although the VA reimburses that hospital for PSG tests provided to its patients, limited capacity at the sleep lab, as well as the budget allocated by the VA for these external studies, capped the number of veterans tested to 10 per week, a volume insufficient to meet the growing requirements. To address a quickly deteriorating level of care, the VA center acquired a few years ago a number of Watch-PAT systems. Today, most patients suspected of OSA, once evaluated in the sleep clinic, are studies with the Watch-PAT. Most such studies are conducted on-site, with patients staying overnight at available beds throughout the hospital, while some patients are sent home with one of the devices. The simple setting of the device and quick data analysis enable the center to run the program with a single respiratory therapist, eliminating the need to hire additional staff.

Patients suspected of disorders other than OSA are still being referred to a sleep lab for PSG, a process that typically requires a few weeks, and at times even a few months, to complete. On the other hand, patients undergoing the sleep study using a portable device obtain the results of their test in the morning after their study, and those requiring CPAP therapy initiate it, using auto-PAP devices, on the day after their study.

Since incorporating the portable studies, average wait time at this VA center has dropped from more than six months to an average of three weeks. In addition, since staring to use the portable devices, the VA center was able to increase the number of patients treated weekly, following either a Watch-PAT or a PSG study, by over 200%, and doing so without adding to the sleep program budget.

Example 2: A regional VA medical center has been operating a two-bed sleep lab, conducting standard PSG studies, and using a number of older portable devices to alleviate peak demand. The operation of the older devices required a technologist to set-up each patient, limiting them to only an in-hospital use. To gain more flexibility and offer studies at patients’ homes in addition to the hospital, the center has acquired a few years ago a number of Watch-PAT systems.

The Watch-PAT devices are used for initial diagnosis, with patients tested positive referred for a split-night PSG study at the hospital’s own sleep lab, while patients with low RDI are recommended alternative options (e.g. sleep hygiene, diet, etc.) without burdening the sleep lab. In addition, the simple-to-use Watch-PAT enabled the center to launch an in-home follow-up program, retesting patients regaining symptoms of sleep apnea despite their compliance with the prescribed CPAP therapy.

Wait time for PSG study in the center is approximately three months and for a Watch-PAT study averages only six weeks. The medical director of the sleep program credits the use of the Watch-PAT to rule-out OSA with the center’s ability to maximize the use of their small sleep lab for the benefit of those patients that do require treatment initiation or must undergo PSG for other clinical or patient-specific reasons.

The optimal role of home studies in managing sleep breathing disorders will undoubtedly continue to be debated, but the current understanding of the prevalence of sleep apnea and its implications on other morbidities require continuous pursuit of improved practices and clinical pathways. Sleep providers have made tremendous progress over the last 10-15 years, offering PSG and treatments to millions of patients with OSA, and are now in a position to leverage new generation of technologies, which offer accuracy and reliability comparable to PSG, to assess patients at alternate settings, including homes, in addition, to sleep labs. Using traditional and new testing modalities in tandem enable broader access, faster service and continuous assessment of treatment efficacy. Fortunately, innovative VA centers have already gained important experience that can help other providers to adapt to the challenges ahead.

David Barone, MSc, MBA
Principal
Boston MedTech Advisors
Boston, MA
E-mail: dbarone@bmtadvisors.com

References

1. Butler M.(2003) VA Tackles Rising Rates of Sleep Apnea. U.S Medicine Information Central, June.
2. Shariq K. (2005) Sleep Centers in the U.S. Reach 2515 in 2004. Sleep, 28:145–146.
3. Sharafkhaneh A. et al. (2004) Sleep Apnea in a High Risk Population: A Study of Veterans Health Administration Beneficiaries. Sleep Medicine, 5:345–350.
4. Harvey R. et al. (2006) Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Committee on Sleep Medicine and Research Institute of Medicine, The National Academies Press.
5. Drobnich D. (2007) Statement by National Sleep Foundation to CMS, April 3.
6. Barone D. Should Sleep Labs Embrace Unattended Studies? Sleep Diagnosis and Therapy 2: 22–24.
7. Diagnosis and Treatment of Obstructive Sleep Apnea. Institute for Clinical Systems Improvement, Fourth Edition/March 2006.
8. Lavie P. et al. (2000) Peripheral Arterial Tonometry: A Novel and Sensitive Non-Invasive Monitor of Brief Arousals During Sleep. IMAJ 2: 246
9. Pittman DS. et al. (2004) Using a Wrist-Worm Device Based on Peripheral Arterial Tonometry to Diagnose Obstructive Sleep Apnea: In-Laboratory and Ambulatory Validation. Sleep 27: 923–933.
10. Herscovici S. et al. (2006) Detecting REM Sleep From The Finer: Automatic REM Sleep Algorithm Based on Peripheral Arterial Tone (PAT) and Actigraphy. Physiol. Meas. 27: 1–12.

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