As awareness of obstructive sleep apnea and other sleep disorders continues to grow, more and more physicians are referring their patients for sleep studies. This is a good thing, and has led to thousands of diagnoses being made that would otherwise have been missed, but it has also created a problem. There is an enormous backlog in availability of laboratory-administered studies. Further, insurance companies are beginning to balk at paying for the tests, which can be extremely expensive. As a result, more and more facilities are turning to home sleep studies. Though traditionalists are against this trend, and point to inaccuracies and lack of complete data obtained from these at-home versions of the test, proponents are indicating that there is a place for these at home tests and that they can prove to be extremely useful.
Because the primary goal of sleep testing is to screen for obstructive sleep apnea, there are specific measurements that need to be taken. These include nasal and oral airflow and respiration. They also include sleep staging, and this requires the use of an electroencephalogram. The tests that are run in sleep labs are generally examined by either a neurologist or pulmonologist who has been specially trained to interpret the results, and who will make a diagnosis based on the data collected. Once obstructive sleep apnea is identified as being present, a second night of testing is usually done in order to determine the severity of the condition and determine the appropriate treatment. Though the testing may be more accurate, there are certain problems. Patients find the environment disruptive and the testing intimidating. They complain that they are unable to sleep in the laboratory environment. There is also the problem of a backlog of patients waiting to be seen, leading to long waits for appointments. Home testing offers a solution to both of these problems, but there are also problems.
The comfort of the home test and the fact that patients feel better able to relax and offer more accurate picture of their actual sleep patterns is offset by the fact that the home-based unattended sleep studies do not provide all of the information that sleep scientists need in order to provide statistically meaningful interpretations. Sleep scientists have argued against the home testing, saying that sleep cannot be staged in the same way at home as in the lab. But advances in technology, the internet and telemetry have eliminated some of those arguments. Much of the equipment has become more portable and easier to use so that patients can operate it themselves. Testing can be monitored over the phone or online. Patients can even be outfitted with CPAP machines that self-adjust to the patient’s breathing and level of obstruction and record the night’s adjustments and activity for the physician to interpret the next day in the laboratory.
With the current backlog of patients and the limited number of sleep centers and beds available, home testing offers a viable alternative that can still provide physicians with valuable information leading to diagnosis. According to Todd Eiken, RPSGT and director of the Metropolitan Sleep Disorders Center in St. Paul, Minnesota, his experience showed that home sleep studies provide great success for patients and their bed partners alike. “There are people who would otherwise never come to a sleep disorders center if it weren’t for portable monitoring, so I think it should be looked at and used.” He admits that the success of the program is subjective, but still feels that it was a success. “The outcomes were positive, but because no technologists were observing them, and the actual titrations were auto-adjust algorithm, we don’t have any objective data indicating the patients had been cured or that the treatments being utilized are the most appropriate for the patients. The upside is that those patients living in rural areas would not likely have traveled to a big city sleep center for treatment.”
The biggest objection that sleep scientists have for home studies is the possibility that the information that is being collected is inaccurate, and may actually end up delaying the correct diagnosis of obstructive sleep apnea. This would not only prove possibly dangerous to patients, but may end up costing more than simply having had the test done in a lab in the first place, as testing ends up needing to be done twice – once for the failed home study, and then once again for the laboratory sleep study. There has been some concern voiced about the auto-adjusting CPAP machines, as looking at the results from different manufacturers and models yielded significant differences in the data recorded. According to Eiken, “In a recent study of four different machines, we used an identical titration pattern, and all of them responded differently. We use auto-adjust CPAP devices in a full-service sleep laboratory for follow-up purposes but not for diagnosis. All anyone really has to go by are the subjective reports of how patients feel. We really don’t know what we did, how it was done, or whether treatment is optimal for that particular patient.”
Others who question the use of the home equipment point out that there is no way of knowing whether everything is being used correctly, or even if the patient that is supposed to be tested is the one that is being monitored.
The concern over accuracy is pervasive, and was the subject of an article written by Pamela Minkley, member and past president of the APT. She worries that the availability of portable units may lead to abuses, and writes, “The quicker and easier it is to do sleep studies in the home, the simpler it appears and the more likely that inexpensive equipment will be available to use in the home, and that physicians untrained in the sleep medicine will be ordering and interpreting the study. Eiken agrees. “There are people out there who provide home testing services and have no idea about recognition of artifact during analysis and rely exclusively on auto-analysis devices. They are very inaccurate, which is another reason why home sleep should be conducted only by sleep professionals.”