(05-16-2016 12:48 PM)SleepyHoosier Wrote: New to this forum, and wanted to thank you all for all the useful information here! Little bit of a backstory first... I was diagnosed about 5 years ago with moderate sleep apnea after a sleep study in the lab. ...
I talked to my family Dr. and he tried to set me up with another sleep study since it's been about 2 years since I've last tried.. My insurance denied the lab sleep study but did approve a home Sleep study. I just got back the results from the home study and it showed that I wouldn't even be considered for a cpap now. Nothing has really changed in regards to losing weight etc, so I'm just wondering how common is this?
My guess is that the discrepancy is most likely due to how the hypopneas were scored on each of the two tests.
I apologize in advance for the fact that much of what follows is quite technical and might be difficult to follow.
Some insurance companies (particularly Medicare) and the sleep medicine community are arguing over what should count as a "hypopnea" on a sleep study. Medicare and some insurance companies insists that a hypopnea must have a corresponding 4% drop in O2 saturation to "count", but the data from multiple scientific studies indicates that "hypopneas with arousals" are just as disturbing to the sleep and can be just as damaging to the long term health of the person. Hence most sleep docs would prefer to use a definition of "hypopnea" that requires a 50% drop in airflow accompanied by either
an EEG arousal OR a 3% drop in O2 saturation and many sleep labs routinely score "hypopneas with arousal" as hypopneas that count towards the diagnostic AHI.
For the past decade or so, the AASM has allowed sleep labs to score hypopneas with either criteria on in-lab test, but they are supposed to say something about which criteria are used in the summary data for the sleep study. For most people, the difference in computing the AHI using the two accepted definitions of "hypopnea" is negligible.
But if you are someone who's main problem is with "hypopneas with arousal", it is possible for the two hypopnea scoring schemes to lead to very different diagnosis. I am one such person: My diagnostic sleep test showed an AHI = 23.1 with a HI = 19.7 and an OAI = 3.9. And I was diagnosed with moderate obstructive sleep apnea
and put on CPAP based on this sleep study. But all
of my hypopneas were scored as "hypopneas with arousal" meaning that none of them "counted" in the Medicare AHI. Had my insurance company followed Medicare guidelines, I would not have qualified for CPAP because my Medicare AHI = 3.9, and with a (Medicare) AHI = 3.9, I would be diagnosed as "does not have OSA" under Medicare guidelines and definitions. (And I have confirmed that interpretation of my original sleep study results with two different sleep docs. A third sleep doc has looked at those results and told me more than once that I do not have OSA and that all my problems are related to borderline bipolarism, which my psychiatrist says I most definitely do not have.)
To complicate matters further: Some home sleep tests are better than others in terms of the data they actually gather. Some of them are pretty simplistic and amount to not much more than an overnight O2 saturation study with airflow data, where the major criteria used to score the events is a combination of drop in airflow with associated drop in O2. Others do have EEG leads or other ways to try to determine the sleep stage, and these studies can do a better job of picking up "hypopneas with arousal".
So to come back to your original question: How is it possible that the in-lab sleep test said you have moderate OSA and the new sleep test says you don't have OSA at all?
My best guess is that the vast majority of your events on the test from 5 years ago were scored as "hypopneas with arousal". And that the home sleep test you took is either not set up to gather EEG data (and hence can't score "hypopneas with arousal" OR the company that scores the data uses Medicare's definition of "hypopnea" for scoring. And if you don't desat with the hypopneas, they don't count towards the home sleep tests AHI computation.
The only way to verify my hypothesis would be to look at the data from the original sleep test. Do you still have the full results of that sleep study from 5 years ago? And if you do have that sleep test report, do you know if you had a high Hypopnea Index with a low Obstructive Apnea Index? And if so, do you know if most of your hypopneas were associated with O2 desats of 4% or more?
Quote:I guess I was under the impression that this would follow me the rest of my life.
Ordinarily OSA is not just going to go away on its own. Particularly if there's been no change in weight or lifestyle.
Quote:Are home studies usually accurate enough?
Maybe. Maybe not. It all depends on whether the home sleep study was set up to detect "hypopneas with arousal".
Quote:The sleep doc wants to see me, but that appt isn't for another month. I'm not complaining that my home Sleep study came back good, just wondering if it's really accurate enough..
Is this the sleep doc who did the sleep test five years ago?
If not, it would be very useful if you can arrange for the original sleep tests results and summary data
to be forwarded to him before
If he's the one who was treating you five years ago, it's worth asking his staff to be sure to dig out the old sleep study report so that you and the doc can go over both reports.
It's also possible that some of the hypopneas on the original sleep study were very marginal events and that today they might be scored as respiratory effort related arousals
. RERAs are not technically part of the AHI. But they can be disruptive to people's sleep. And there's a relatively new diagnosis call UARS (upper airway resitance syndrome) that is also somewhat controversial. Patients with UARS typically have low AHIs---as in AHIs that are well below the usual 5.0 needed to diagnose mild OSA. But patients with UARS also present with many of the same OSA symptoms: Lots of daytime exhaustion, brain fog, sometimes an awareness that the sleep is bad. They often don't have any snoring and bed partners may or may not say anything about witnessing problems with the night time breathing.
Treatment of UARS is usually with CPAP. Some insurance companies will routinely cover it. Others will question whether CPAP is necessary.
Good luck in finding some answers.