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WatchPAT false positive? - Printable Version

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WatchPAT false positive? - Fabrice01 - 01-07-2025

This study https://jcsm.aasm.org/doi/10.5664/jcsm.9808 suggests "clinically significant discordance between WatchPAT and PSG measurements of AHI [and] significant sleep apnea severity misclassification by PAT studies".

I had two PSG home tests - one in 2017 and the other in 2022. Both yielded AHI barely above normal range (AHI = 8 for first one, can't remember second one).

Then a WatchPAT One test a couple months ago yielded AHI = 46.

I was told WatchPAT is more advanced and should probably be trusted. Two nights ago I was able to sleep for 7h with a APAP Airsense 10. It yielded AHI = 1.5.

Am I right in concluding that I do not have OSA and that the WatchPAT test was wrong in my case?

I would be back to square one though: I still have no idea why I wake up every hour at night, why I'm constantly crushed by heavy fatigue, or why I experience frequent mild shortness of breath that worsens when I didn't sleep enough.

But if I don't have OSA then this question is not particularly for this board I suppose.

RE: WatchPAT false positive? - Fabrice01 - 01-07-2025

Just in case here's my OSCAR data. I fell asleep around 4am I think then woke up a few times every hour or so.

[Image: WLYxohp.png]

RE: WatchPAT false positive? - Deborah K. - 01-07-2025

Sure you have apnea.  The 1.5 you are getting now is because of your treatment, not because you don't need a machine.  Most who have pretty low AHIs in their sleep studies still need their machines.  Also, your WatchPat study may have been accurate.  Your apnea may have gotten worse over time.  Stick with your machine.  

Good luck!  Smile

RE: WatchPAT false positive? - Fabrice01 - 01-07-2025

(01-07-2025, 04:48 PM)Deborah K. Wrote: Sure you have apnea.  The 1.5 you are getting now is because of your treatment, not because you don't need a machine.  Most who have pretty low AHIs in their sleep studies still need their machines.  Also, your WatchPat study may have been accurate.  Your apnea may have gotten worse over time.  Stick with your machine.  

Good luck!  Smile

Thank you Deborah! Just to be clear: on a few occasions some years ago, I slept for several hours in a row with CPAP pressure = 10 without feeling better during the day and still waking up every hour at night, and because PSG said AHI = 8 I thought CPAP doesn't help + I don't really have OSA anyway. So I gave up.

That was a long time ago. The night corresponding to the OSCAR screenshot above is my first real PAP night after many years.

The day after that night, I felt exactly the same as usual. And during that night I still woke up every hour.

Are you sure my low AHI is actually the work of PAP therapy? If so, is it possible to see it in the OSCAR data? And, why am I not feeling any different?

RE: WatchPAT false positive? - SarcasticDave94 - 01-08-2025

Part of the issue is you had 5 sessions within the chart, each with Ramp stealing therapy time. I'd try going without the Ramp.

Second, the area in the middle with a few clustered events might have been a Positional Apnea pattern, meaning you'll need to examine your pillow for being extra thick as a cause for pushing your chin towards your chest. It can also be side sleeping and your chin tucking similarly. It's much like kinking off your water hose, it's external and needs a physical prevention, if this is happening.