Vol. 11 •Issue 6 • Page 29
Experts Debate Merits of Unattended At-home Sleep Tests
On April 1, the Centers for Medicare and Medicaid Services fired the latest shot heard round the world of sleep medicine. Medicare’s purse-string-holders announced they would pay for continuous positive airway pressure titration only if performed in a sleep lab, not in the home.
Previously, the agency had nixed coverage for unattended at-home polysomnography testing. Together, the two rulings complete a slam-dunk for sleep lab purists, who were elated at the latest development.
“That makes sense,” George Burton, MD, medical director of the sleep lab at Kettering Medical Center in Ohio, said of the government’s decision. “If they couldn’t convince Medicare, that tells you something. (Home study equipment) is still user-unfriendly.”
CMS officials “woke up to the fact that you can’t do a proper CPAP titration at home, unless you have a tech in the room with you,” said Steve Grenard, RRT, research coordinator of the Sleep Apnea Center at New York’s Staten Island University Hospital. “Auto-titration equipment is not dependable for doing unattended CPAP titration in the home. Auto-CPAP was developed for obstructive sleep apnea patients who couldn’t tolerate high pressures for all phases of the sleep cycle. It was not developed for home studies.”
Proponents of at-home sleep monitoring, meanwhile, were bowed but unbroken. “It’s disappointing,” said Bruce Adornato, MD, medical director of .Sleep Solutions Inc., a manufacturer of ambulatory sleep testing equipment. “It’s a step backward in extending readily accessible sleep diagnostics to Medicare patients.”
The elderly have more sleep apnea than younger people, asserted Dr. Adornato, a clinician who has founded two sleep labs and previously directed Stanford University’s sleep lab in San Francisco. “My message to Medicare is, ‘There are lots of older people with apnea. We need to make diagnosis easier for them. You’ve erected another roadblock here.'”
Medicare’s ruling is the latest wrinkle in a contentious, decade-old debate over the merits of sleep-disorder testing performed in the home without the presence of a technician. Those in favor of ambulatory sleep studies argue that patients prefer to undergo medical procedures where they live rather than in the foreign confines of a clinic. They also make the utilitarian argument that some areas of the country, especially rural locations, have no sleep centers, so home studies are better than no studies. Lastly, they cite heavy patient backlogs at existing centers and the allegedly lower costs of home testing.
Opponents counter that unsupervised patients easily can dislodge delicate sensors during the night, rendering the results incomplete or invalid. Plus, ambulatory sleep testing equipment is considerably less comprehensive than lab-based 16-channel polysomnography. The American Academy of Sleep Medicine says home recording units must measure at least four channels: heart rate, arterial oxygen saturation, airflow and breathing effort.
In assessing the merits of at-home testing, sleep physicians must balance the benefits of true positive readings against the consequences of false negative or false positive readings, observed Peter Gay, MD, of the Mayo Foundation, Rochester, Minn., during a recent lecture. What are the savings to society by correctly diagnosing and treating a patient with ambulatory equipment? And what is the cost of a patient denied treatment due to a false negative score, or of giving a patient treatment he doesn’t need?
Loyalists on both sides of the issue hold, at times, strikingly opposing views.
Asked how ambulatory equipment can improve the practice of sleep medicine, Dr. Adornato first cited limited accessibility. “Approximately 4 to 5 percent of the U.S. population are felt to have sleep-disordered breathing,” he said. “Therefore, 6 to 8 percent may need testing. The current number of labs is unable to handle that demand.”
Grenard acknowledged that many centers, including his eight-bed lab, are backlogged. His solution is a practice common in the airline and hotel industries: bumping. “If it’s not an emergency, we’ll get you in in three weeks,” he said. “If you are an emergency patient, we will bump somebody. Somebody’s wife will call, crying, saying her husband is a school bus driver; he’s already had two accidents. If we thought you would kill yourself in a car accident, we’ll get you in now.”
Where sleep centers don’t exist, unattended studies are indeed better than nothing, Grenard conceded. But why not try instead to persuade your hospital administrator that a sleep diagnostics lab is a sound investment?
“The money is there from payers,” he said. “Home study companies in the New York area require customers to pay cash. Hospital-based labs like ours take insurance. If (administrators) are not sure about it, they might consider contracting with a private company to do it for them.”
On the matter of patient comfort, Dr. Adornato said, “A lot of men and women simply don’t want to sleep in a laboratory. I go to a lab at 8 p.m. It takes them a few hours to wire me up and start the study, since one technician handles several patients. They tell me to go to sleep at 11 p.m. I probably feel anxious with wires all over me, people watching me. The architecture of my sleep is altered.”
Grenard sees it differently. “People with sleep apnea are exhausted,” he pointed out. “They can sleep anywhere, anytime — that’s their problem. A patient could be asleep before the hookup is done, in a chair — or behind the wheel.”
Labs today, he added, usually have queen-size beds and “feel very home-like.”
Regarding costs, several large HMOs report considerable savings from unattended ambulatory studies, said Dr. Gay. Kaiser California, for instance, estimates its five-year savings from using unattended sleep studies at $1.7 million, he said. Seattle’s Puget Sound HMO, with more than 600,000 members enrolled, conducted a two-year examination and determined its total cost per patient decreased by 36 percent using home study equipment.
Sleep Solutions ships its diagnostic system to patients, who use it for three nights then ship it back to the company to process for “less than half the cost of an overnight in-laboratory sleep study,” according to its Web site.
“The cost of doing a sleep study in a lab is high, $600 to $800 depending on where you are in the country,” Dr. Adornato said. “Medicare has relatively low reimbursement that disincentives study of older patients.”
Lab-based clinicians counter that the failure rate of home testing negates any savings.
“The Associated Professional Sleep Societies does not support their use except as a screening procedure,” Dr. Burton said. “The reason is you can only tell if patients are asleep or awake from EEG. But EEG leads are very fragile and come off easily. There are great problems with repeat home studies. Why not just bring them into the lab in the first place?”
Sleep Solutions’ system measures airflow, chest effort and oximetry/heart rate, quantifies snoring, and has a warning feature that alerts wearers to sensor malfunctions. It does not, however, include electroencephalography.
“It’s not practical to do EEG in the home,” Dr. Adornato explained. “It requires the presence of a technician, or else you have unacceptably high loss rates. You have to make choices between having everything and having enough. In terms of public health, perfect is not the answer. If I can do a hundred perfect studies a month, but my community needs a thousand studies a month, how am I best serving the community?”
Some sleep physicians even reject at-home testing as a screening mechanism. Grenard’s sleep center has adopted a far simpler way to screen: Have patients fill out the Stanford Sleepiness Scale. Obtain their Epworth scores. Then give their oropharyngeal airways a cursory exam with a pocket flashlight. With these simple tools, the center has achieved a 97.5 percent rate of positive prediction for OSA.
What’s more, a home study wastes money because it delays treatment, Grenard added. “After they do the first home study, the patient can’t wake up and put himself on CPAP,” he pointed out. “So they must come back a second night for that. What are you doing that for when in a lab you can spend two to three hours screening and then put them on CPAP that same night in a split-night study?”
Dr. Adornato, however, questions the methodology of split-night studies because patients are only recorded for a few hours. “Once they start obstructing in the lab, they are placed on CPAP,” he said. “You never really know the true severity of their apnea because the worst apnea/hypopnea episodes occur at 4 or 5 a.m. Split-night studies don’t go that far.”
In fact, sleep labs in general are hardly sacred cows, he continued. “About a third of labs are accredited or subject to uniform testing, and they are only looked at every five years,” he said. “Even though standards exist, in actual practice there is considerable heterogeneity among sleep studies.”
Perhaps the most compelling and influential nod in favor of home testing emerged recently from a cross-sectional analysis of data gathered prospectively for the landmark Sleep Heart Health Study (SHHS), an ongoing research project by the National Institutes of Health.
A total of 6,802 SHHS participants had at-home studies performed using portable equipment that included EEG, electro-oculography, electromyogram, oronasal thermocouple, oximetry/heart rate, body position and ambient light. The researchers deemed 6,161 initial studies acceptable, a success rate of 90.6 percent. After one or more attempts, 6,440 participants (94.7 percent) had acceptable studies.1 Thermistor hookup/failure caused 10 percent of the home study failures.
Nevertheless, satisfied SHHS investigators concluded: “This study suggests that unattended home PSG, when performed with proper protocols and quality controls, has reasonable success rates and signal quality for the evaluation of SDB in clinical and research settings.”
Is home monitoring for sleep-disordered breathing here to stay?
“I hope it’s not,” Dr. Burton said.
“It might be inevitable in some areas,” Grenard admitted.
Dr. Adornato likened the conflict to 30 years ago, when cardiologists resented computerized scoring of electrocardiograms, preferring to scan entire strips themselves. Today, computers analyze the same data in a fraction of the time — with better results.
“I think all rational physicians realize that someday these types of tests will be computerized, automated and done in the home,” he concluded. “The question is, when is that going to be?”
1. Kapur, VK, Rapoport DM, Sanders MH, et al. Rates of sensor loss in unattended home polysomnography: the influence of age, gender, obesity and sleep-disordered breathing. Sleep. 2000 Aug 1;23(5):682-8.
Michael Gibbons is senior associate editor of ADVANCE.