AASM Guidelines Give Qualified Endorsement to Portable Sleep Monitoring; CMS Proposes

Pauline Anderson
Portable sleep-monitoring devices can be used to assess patients suspected of having moderate to severe obstructive sleep apnea (OSA), according to new guidelines released by the American Academy of Sleep Medicine (AASM).
But the monitoring machines should be used only by adult patients who have no other sleep disorders or significant comorbid medical conditions, and their use should be overseen by accredited sleep specialists, according to the guidelines, which were developed by a special task force of the academy chaired by Nancy A. Collop, MD, from Johns Hopkins University, in Baltimore, Maryland.
The guidelines are published in the December 15 issue of the Journal of Clinical Sleep Medicine.
Finally as Effective as In-Laboratory Standard
At-home sleep monitoring machines have been around for about a decade, but until now the technology has not been comparable with in-laboratory polysomnography, according to Lawrence Epstein, MD, medical director of Sleep HealthCenters in Brighton, Massachusetts, who was not a member of the task force but is past president of the AASM. In recent years, the academy has prepared 3 reviews of the scientific literature on portable monitoring, "keeping an eye on when the technology finally became as effective as the standard in the laboratory," said Dr. Epstein.
Portable monitoring systems typically consist of a small recording device, sensors, belts, and related accessories. Worn by patients while they sleep at home, they can be used to assess signs of OSA, a condition in which people temporarily stop breathing due to an airway obstruction. Access to these devices is usually through sleep centers located in a hospital or separate clinic setting.
The task force developed the guidelines after reviewing 36 studies published between 1997 and 2006 (and 1 in 2007) that included adults evaluated for OSA with portable limited-channel devices (usually 4 to 7 channels).
Not Appropriate for Other Sleep Disorders
The guidelines contain several recommendations for using portable monitoring devices. Their use should be limited to patients whom doctors deem to have a moderate to high pretest likelihood of having OSA; they should not be used in cases of central sleep apnea, periodic limb-movement disorder, insomnia, parasomnia, circadian rhythm disorder, or narcolepsy.
Another caveat, said Dr. Epstein, is that the testing should be done in people who have no other medical conditions that could interfere with the monitoring. So patients with, for example, congestive heart failure or stroke would not qualify, he said.
Portable monitoring devices are not recommended in children, either, and few studies of portable monitoring include patients older than age 65 years, since older people tend to have additional medical problems. The majority of patients who develop OSA are in their 40s and 50s, said Dr. Epstein.
Trained Specialist Oversight
The task force emphasized the importance of board-certified sleep specialists — or those fulfilling eligibility criteria — overseeing portable sleep monitoring. These specialists can interpret the results of the at-home sleep test and develop a treatment plan if the results indicate a patient has OSA. In the United States, there is a board certification in sleep medicine as well as sleep centers accredited by the AASM.
The task force concluded that portable monitoring should not be used to screen people who have no signs or symptoms of a sleep disorder even if they are in a high-risk group. Although screening may be appropriate for asymptomatic people such as truck drivers and those undergoing bariatric surgery, "currently available portable monitoring devices are not acceptable tools," the task force members write.
As well, the task force made some recommendations surrounding portable monitoring technology. It said that monitoring systems must record airflow, respiratory effort, and blood oxygenation. The same biosensors used to monitor these parameters for in-laboratory polysomnography should be used in portable monitors, according to the guidelines. The task force also said that portable monitors should ideally use both an oronasal thermal sensor to detect apnea and a nasal pressure transducer to detect hypopnea.
Could Decrease Wait Time for Diagnosis
Although at-home sleep monitoring systems have a higher failure rate than in-laboratory polysomnography (the equipment can fall off during sleep, with no technician available to replace it), it may decrease waiting time for diagnosis. At present, not all patients have easy access to a sleep laboratory.
The technology may also decrease costs. "You have a higher rate of repeat testing with the portable monitoring but a lower cost of the equipment and overhead," commented Dr. Epstein. He said researchers are currently undertaking a cost/benefit analysis of portable monitoring vs laboratory testing.
Extended Coverage
Coinciding with the release of these new guidelines was an announcement from the Centers for Medicare & Medicaid Services (CMS) that it proposes to extend coverage of continuous positive airway pressure (CPAP) based on diagnoses using portable monitoring, specifically type 2, 3, or 4 home sleep tests.
Coverage currently extends only to treatments following diagnoses made through in-laboratory polysomnography. CPAP is the accepted gold-standard treatment for OSA.
"Our proposed policy to extend coverage for continuous positive airway pressure provides more options for Medicare beneficiaries and their treating physicians," CMS acting administrator Kerry Weems said in a statement.
The CMS also proposes to expand coverage of CPAP under the coverage-with-evidence-development process to include beneficiaries who have been diagnosed with OSA based on a clinical evaluation alone, a diagnostic test other than polysomnography, or a type 2, 3, or 4 home sleep test; however, to be covered, participation in a research study is required, it notes, and the studies must meet the standards of CMS clinical trial policy.
In addition, CMS proposals include modifying the requirement for a minimum of 2 hours of continuous recorded sleep during tests because some patients with very severe OSA cannot meet this requirement. The proposed policy would consider a test positive if the total number of required sleep disturbances is achieved for more than 2 hours, regardless of whether 2 hours of continuous sleep have occurred, the CMS statement notes. It also proposed any initial coverage of CPAP for OSA be limited to 12 weeks to determine whether the patient will respond to treatment.
The CMS plans to issue a final coverage determination in March 2008. In the meantime, it invites public input on the proposed changes.
This was not an industry-supported study. The study authors have disclosed no relevant financial relationships.
J Clin Sleep Med. 2007;3:737-747.