Question about hypopneas

[HalfAsleep]

It may be my failing eyesight but I could not find any Medicare specs for scoring hypopneas at that link.

Best Regards,

PaytonA

The definition for the hypopneas as AHI on my sleep test looks to be events via O2 desat, as above. That seems to be what Medicare cares about. See the screen shot in attachments.

Again:
Includes hypopneas with an arousal or with a 3%-4% desaturation. CMS Hypopneas not included. 
CMS-defined hypopneas include only hypopneas with a >=4% oxygen desaturation.

Mine also have a duration shown.

[Timur]

Thanks Halfasleep, so Medicare uses the 4% or greater desaturation as per the AASM's "acceptable" standard.

 That means that a lot of people under Medicare will not be diagnosed with sleep apnea and get treatment, especially those who have mainly 3%  desaturations or mainly arousals without significant desaturations. 

I'm glad that you qualify, and hope that CPAP helps. 

As I mentioned earlier I've run the User Flagging option in SH as suggested to identify a 30% reduction (UF1) and a 50% reduction (UF2) in airflow.

Since the definition for hypopnea in my overnight study was a 30% reduction in airflow for 10 seconds (etc.) I figure I will use the User Flag option in future as well to see how those are being treated and how often they occur. They are not included in the AHI as per Resmed. 


I fiddled around a bit and see that one has to set the airflow to 70% for some reason for this to work, rather counter- intuitive but setting it at 30% yields no results, whereas at 70% does so I assume this is correct. 

Quite interesting to see how it looks in SH. Here is an example:

[pholynyk]

The User Flag definitions (as well as the hyponea defintions) are unclear as to whether they mean a 30% drop from 'average' or a drop to 30% of 'average'... quite a difference! 
In practice, SleepyHead uses the 'drop to xx% of average' for the User Flags. I know this because I get lots more UF2 events than UF1 events.

[Timur]

Thanks Pholynyk. 

Yes I changed the 30% default for 10 seconds or more for UF1 to 70% in the example above, with UF2 set at the default of 50%.

When I use the default setting of 30% for UF1 this is the result for the same night .... no events reported.

So should I leave it at 30% or change it to 70%? I'm confused.

EDIT TO ADD: Also I just checked about two months of data in SH and with the default set to 30%. I have virtually no events showing up under UF1 and just a few under UF2, the same as you report.

[HalfAsleep]

Thanks Halfasleep, so Medicare uses the 4% or greater desaturation as per the AASM's "acceptable" standard.

 That means that a lot of people under Medicare will not be diagnosed with sleep apnea and get treatment, especially those who have mainly 3%  desaturations or mainly arousals without significant desaturations. 
 (UF2) in airflow.

That appears to be correct regarding Medicare coverage and difficulty of meeting the spec. Actually, that's what happened to me until we looked again at the spec. However, I couldn't venture to guess how common it is. One suggestion from the doc was to retake the test and see if my CMS AHI went up since my sleep study was complicated by the fact that I had to move to a different room in the night and I was wired on the wrong side so I had to sleep on the entire pile of wires.
The Medicare spec doesn't distinguish between hypopneas and apneas.
I'm not advanced enough to engage in discussion about airflow. Give me a few weeks...

[Timur]

Halfasleep, I'm learning this as I go along as well. 

I suspect that the airflow reductions I'm talking about here in this thread are probably not of any real significance compared with the machine reported AHI,  unless someone is battling to sleep or still feeling fatigued and reporting low AHI numbers. Then maybe, if they turn out to be very numerous and possibly of long duration .... and even then I am not sure how reliable these user flagging events are compared with lab studies.

[holden4th]

Thanks to this thread I have discovered how to change from AHI to RDI. More importantly, my time is out by about an hour. I can adjust this in SH.