Home sleep testing might soon play a bigger role in sleep medicine.

By Franklin A. Holman

In-laboratory polysomnograph equipment manufacturers and respiratory therapists involved in sleep medicine would be wise to learn how to best adapt to an increased use of home testing for sleep apnea patients.
With more studies supporting the use of home testing, and with the Centers for Medicare and Medicaid Services re-evaluating its diagnostic coverage criteria for CPAP for obstructive sleep apnea patients, home testing might soon play a bigger role in sleep medicine. Permitting home testing could impact the business of sleep laboratories and manufacturers of PSG products, and could also mean changes in the way that RTs evaluate OSA patients.

RT  spoke with Mark Rizk, RPSGT, senior product manager, business unit manager—sleep products, Nihon Kohden; Jeffrey Kuznia, RRT, RPFT, director of business development for Compumedics USA Ltd; and Kassandra Keller, director of marketing and product development, Embla, about home testing, the outlook of the PSG market, and what the future holds for RTs involved in sleep medicine.

RT: A study in the February 2007 edition of the journal Annals of Internal Medicine finds that home testing for sleep apnea patients with a high likelihood of OSA is as effective as in-laboratory PSG in terms of patient outcomes. As home testing experiences technological advances and increased validation, what role will in-laboratory PSG play?

Mark Rizk: The in-lab PSG is still going to be the gold standard for diagnosing every type of sleep disorder. For example, tests for narcolepsy and restless legs syndrome are going to be done with PSG. There are still going to be a significant number of sleep-related breathing disorder patients who are going to be tested with full PSG, because their cases aren’t so simple. If—or I think it is more of a question of when—home testing becomes authorized, sleep labs are going to have a lot more credibility if they have a PSG laboratory with sleep experts working there to evaluate patients who need a follow-up PSG study or who need an in-lab PSG study in the first place.

Jeffrey Kuznia: Surprisingly, in recent years, markets that have been predominately home based have experienced an increased demand for in-lab PSG studies. This may reflect a maturing of these markets and a realization that with many sleep disorders patients cannot be effectively assessed with only limited-channel PSG studies and might require direct visual monitoring to completely evaluate their complaints.

We do not anticipate a reduction in demand for the in-lab PSG testing; instead we expect that as home-based PSG testing continues to evolve, those patients studied in the traditional sleep lab will be those with more complex issues. We also believe it logical that most traditional sleep labs will expand their service model to include support for home-based testing.

Kassandra Keller: In-lab studies will continue to play a valuable role in diagnosing sleep disorders. Identifying mild cases of sleep-disordered breathing that may not be diagnosed by home testing methods, as well as ruling out other possible sleep disorders, lend themselves to an in-lab testing environment. In-lab PSG is also important for applying and recognizing optimal therapy or alternatives such as pharmacotherapy. The in-lab PSG will also continue to be vital in assisting the physician in identifying all primary or secondary sleep-related complaints such as narcolepsy, periodic limb movements in sleep, restless leg syndrome, erectile dysfunction, etc.

RT: On March 14, 2007, the CMS reopened the issue of whether its diagnostic coverage criteria for CPAP should allow other forms of testing in addition to in-laboratory polysomnography. How could the outcome of this review impact RTs who use PSG? What is your position on this issue?

Rizk: The role of the RT could be substantially increased in doing home testing depending on what the standards for the test will be. If there is a big thumbs up on home testing, I think more RTs are going to be involved in sleep than they have in the past.

There are a lot of people that benefit from home studies—the patients obviously are the biggest group. I don’t see home testing taking over the entire market tomorrow, but it will have an impact. You have got to realize that 60% to 80% of the people who have diagnosable sleep-related breathing disorders are going untested. Home testing is going to address a lot of that population, but there still are going to be that 10%, 20%, 30%, or whatever the percentage may be who are going to be tested in a sleep lab. That population is not going to disappear. There is still going to be a need and demand for in-lab PSG.

Kuznia: The issues with the National Coverage Determination currently under review by CMS is partly economic and partly clinical. The cost of providing in-lab PSG testing is high enough that alternative approaches with a potential or proven lower cost structure should be evaluated and, if found useful, valid, and cost-effective, should be reimbursed. From a clinical perspective there is an open question of what alternative approaches to in-lab PSGs have been shown to be useful, valid, and cost-effective and with what patient populations have these points been documented. CMS will be reviewing the data presented by various parties and technologies that address these issues. The link to CPAP is a secondary issue since diagnostic evaluations for other treatment approaches, such as the use of oral appliances or surgery, may be affected by their decision.

A lot depends on what CMS concludes should or should not be reimbursed. The impact of the decision on technicians involved in sleep testing will depend on the details of what is approved. Regardless, I think that it is important to realize that the traditional sleep lab will not be replaced by home PSG testing and may in fact be more important as home studies uncover more people with complex and difficult to diagnose sleep disorders that can be evaluated only in the traditional sleep clinic setting.

In the end, the PSG study, whether in the lab or in the home, is a tool used by a trained sleep physician as part of their diagnostic workup of the patient. A knowledgeable physician who understands how to use the data from any of these devices is what may be the most important factor.

Keller: Should CMS allow methods other than in-lab PSG testing for CPAP criteria, it will likely change the way some patients are diagnosed. Depending on how the change is implemented, the models for how health care professionals such as RTs are impacted are somewhat difficult to gauge. The methods under consideration are essentially limited PSG that include a fewer number of channels, but are quite similar to what is recorded in-lab. The RT familiar with in-lab PSGs will certainly be well positioned and will likely have increased professional opportunities as more patients have access to care.

Embla supports any decision that provides communities with increased access to diagnosis and care.

RT: What is the biggest misconception about PSG devices?

Rizk: When diagnosing a sleep disorder, it is important to know if the patient is actually asleep, and even though their breathing may appear regular and their saturations may appear normal, that they are indeed having sustained restful sleep. This input isn’t readily available with a home test, and that fact is not given enough weight in in-lab polysomnography. When home testing, you can’t really get the same flavor of what is causing a person’s sleep disturbance, how sleep disturbed they are, how well they are sleeping as a result of their better breathing, or if they are sleeping at all.

Kuznia: I think that one of the biggest misconceptions about PSG devices used in the home is that they somehow require less knowledge by the physician and technicians to be used effectively. In fact, the opposite might be true. The data recorded using a device with fewer channels could require a more thorough understanding of sources of artifact or unusual responses before the data can be relied on for diagnostic purposes.

Another misconception is that PSG devices used for the home testing can be grouped together. Nothing can be further from the truth. The reality is that there are many types of products with a wide range of capabilities and with different limitations that can be significant when attempting to evaluate patients.

RT: Tell me about your company’s recently developed PSG devices; why are they innovative for RTs who are involved in sleep medicine?

Keller: I believe that the biggest misconception about PSG devices is that they are very complex to use and that there is little to no differentiation between one device and another. What Embla’s market research has shown us is that the PSG devices that are successful are streamlined in design, facilitate intuitive hookup, and are reliable. Our industry has gone from huge analog polygraph machines to full PSG devices that fit in the palm of one’s hand.

Rizk: Nihon Kohden’s Polysmith sleep lab system for sleep assessment features comprehensive, easy-to-use analysis for sleep studies. It analyzes effectively all types of tests from respiratory home tests to advanced EEG tests but does it in a way that is simple to use. The end tidal CO2 analysis and the end tidal CO2 technology that we use are also very beneficial for RTs and one of the strong respiratory aspects of our sleep product line.

Kuznia: Compumedics has a long history of innovation in the business of PSG devices. The Somté system was the first body-worn recorder that could be used to evaluate sleep-disordered breathing with state-of-the-art nasal pressure sensors for airflow, and respiratory inductive plethysmography for effort, oximetry, and body position with two channels that can be set up for EEG, EMG, EOG, or ECG recording. We recently released an extension of this product line in Australia and Europe (currently pending FDA market clearance), the SomtePSG, which records a full 16-channel PSG for use within or outside of the sleep lab.

RT: What kind of feedback have you received from users of your products?

Keller: Embla is unique in that we offer the broadest range of sleep diagnostic products, from two channel screening devices to research level polysomnography devices. All of these systems are integrated into a single sleep software program. In addition to our breadth of line, we continue to develop devices that incorporate new technologies that provide additional memory, wireless technology, improved ergonomics, and increased reliability. These innovations enable the RT to focus on patient care rather than the equipment.

Rizk: People have described Polysmith as very comprehensive. It can be used to analyze and record virtually any kind of patient—whether adult or pediatric. It is beneficial for a research lab, but at the same time, it is easy enough to use for any clinical sleep lab. It also has a data-management system that is really well proven. Other people have said that it is a stable product that has been used in many different environments, and as a result, it is a very useful data management system. This product is affordable and uses a MYSQL database engine. It allows us to give a great deal of flexibility and growth into a data management system for an inexpensive price.

Kuznia: The P-Series system was very successful around the world because it was easy to work with and reliable, and produced data with excellent quality. We have had the same response from users of our newer products like the Somté and Safiro PSG systems. The SomtéPSG system has just entered the world market, and, based on initial feedback, it appears that the users continue to be highly satisfied with its performance.

Keller: Embla is committed to providing the best sleep diagnostic products and services on a global level. Our focus is to be closer to our customers. Customer feedback is essential and is the driving force behind our continued development. We place great value on the input users have on our products, which includes both praise, as well as suggestions for improvement. We solicit this dialogue with a variety of methods, including frequent user-group meetings that provide us with valuable feedback on our products and services and allow us to continually improve. RT