Recently while being interviewed during a webinar I was asked, “Which is a better method of testing for Obstructive Sleep Apnea (OSA), portable sleep testing or monitored polysomnograph (PSG) tests?”. During the heated discussion it became obvious to me that this is a controversial subject with many factors and extraneous influences. So, which is better a home sleep test or PSG? To quote many of my Pankey Institute mentors – I think the answer is “it depends”. I truly don’t say that to be ambiguous but merely as a statement of opinion depending on the circumstances. I think that in dentistry, and even more in the area of dental sleep medicine, we desire a panacea i.e. fix-all for each of our procedures, dental sleep devices, etc. Well, the truth of the matter is that one shoe does not fit all sizes and that we need more than one instrument to do a comprehensive job in most areas in the treatment of sleep apnea. I do have a preference for most situations and I will be happy to share that with you after I review the factors that go into the decision process. Let’s talk about the merits of each of to help with our decision process.
Contents
Polysomnograph (PSG)
The PSG has been the gold standard for diagnosis of OSA and other sleep disorders for many years. In fact, until recently, it has been the only “legal” method that would be reimbursed by insurance for diagnosis in the United States.
The test is conducted in a controlled environment which has many advantages. The patient can be monitored and aided to sleep in different positions to assess body position effects on sleep patterns. Also the controlled environment can keep outside influences from affecting the patient’s sleep, such as noise from the home environment, distractions from television, and the influence of alcohol and other non-prescription substances. Furthermore this environment enables first hand monitoring of the patient and equipment to ensure that there are no equipment failures or other problems. If the signals from any of the proxies (leads) are inadequate they can be immediately adjusted to insure an adequate nights’ test.
In a PSG, EEG’s, EOG’s and EMG’s are utilized to obtain sleep staging and arousal information as well as parasomnia activity such as periodic leg movement. Furthermore if the patient does have OSA, a CPAP titration can be performed sometimes on the same night utilizing the “split night” protocol.
To summarize, the advantage of PSG testing for OSA is that it is a more accurate study analyzing not only breathing patterns and oximitry but also sleep stages and arguably the quality of sleep.
Home Sleep Study (HST)
Well, if the PSG is a more accurate study then it is better, right? Hold on just a second! Before we rush to conclusions let’s give the home sleep test a chance. First of all let’s define the home sleep study. During this discussion I am speaking about a Level III sleep recorder. I also believe that the Level III sleep recorder should measure all of the channels that are used during a PSG for the diagnosis of OSA which are:
- Nasal airflow
- Heart rate
- Oximitery
- Abdominal effort
- Thorax effort
- Body Position
- Snoring
In my opinion the first 6 channels are mandatory for an ambulatory study if it is going to be used for diagnosis. Think about it, how do we define apnea, hypopnea and discern between central and obstructive OSA? These are the channels needed and they are also the ones that are utilized by the polygraphic technician when scoring a PSG for OSA. In my practice I utilize the Embletta X100 for home sleep tests because it measures these channels, is compact, accurate and is made by the largest home diagnostic company in the world (Embla).
Now back to the advantages of the home sleep study. First of all the obvious, it is completed in the patient’s home. It is much better accepted by patients than a PSG in the sleep lab. Since I have been utilizing my Embletta X100s for home sleep tests (along with the help of a board certified sleep physician) the number of my patients who have agreed to undergo a sleep study and ultimately became diagnosed has increased immeasurably. The other advantage to being at home is the patient is going to have a more accurate night’s sleep. In other words they are going to sleep more like they normally do. It has been well documented that patients often times do not sleep as soundly in a monitored sleep environment (PSG) and often will have a “first night affect” where the OSA is under-diagnosed due to poor sleep quality.
The other advantages to the home sleep test are that the cost can be dramatically less and access to care is greatly increased with HST utilization. PSG can cost from $1,500 to over $2,000 while a HST typically is less than $300. PSGs require more equipment, staff, and facilities which make access to care more difficult and expensive.
There are a few negatives to the HST. For one, the leads may become loose or lose their signals. During a PSG this problem can immediately be corrected but in the HST the entire study may need to be repeated. Also, certain other sleep disorders may not be able to be diagnosed without the EEG and EMG readings from the PSG. This is why the AASM recommends anyone who is at risk for OSA, who is tested with a HST that obtains a negative result (no apnea), complete a PSG to look for other sleep problems and verify the accuracy of the HST.
The Decision (my opinion)
To put it in a nutshell, a PSG is a more accurate night’s study of an often less accurate night’s sleep. So which is better? I told you I would give my opinion and here it is. I believe for most circumstances that the HST has advantages that outweigh the PSG for diagnosis of OSA and other sleep disorder breathing. If we are looking primarily for obstructed breathing then a HST like the Embletta X100 measures very accurately everything we need and while the patient is sleeping better in their normal environment, for less cost and with easier access to care. There! I told you my opinion which is not always popular within the medical community .
That being said, in certain circumstances involving co-morbidity, complex medical histories, diverse symptoms, and negative responses to HST, then the PSG is definitely indicated.
Dental Sleep Solutions® Protocol
In my office we utilize the Embletta X100 for testing of our patients along with assistance from a local board certified sleep physician. We fit the patient with the sleep recorder, send them home for the night, then download the results the following day. We then supply the board certified sleep physician the raw data through our web server along with the patient’s medical information. The diagnosis is made by the sleep physician and given to us and the patient’s primary care physician. The patient then makes a decision as to the course of treatment.
I have been utilizing this system for about a year in my office and have seen the diagnosis and treatment of OSA from my patients of record increase dramatically. As always with innovated methods, some may criticize this system. But, I now have many patients who have been diagnosed and treated for OSA who would otherwise be living with (at least for the time being) their disease. I can live with the criticism because I know my patients are living better and longer.
