[Diagnosis] Comparing AHI Accuracy: ResMed AirSense 11 vs. In-Lab Sleep Study

[NightmaresOfTheBottom]

1.  How accurate is the AHI reported by a ResMed AirSense 11 APAP compared to the AHI from an in-lab sleep study conducted by a sleep technician? 
2.  Do APAP devices like the AirSense 11 tend to underreport AHI due to having fewer sensors or less comprehensive monitoring? 
3.  For those of you who have undergone in-lab titration studies, how closely did the AHI reported by your APAP align with the AHI recorded during the sleep study? 
4.  Has anyone used a medical-grade Nonin pulse oximeter in conjunction with the AirSense 11? Does the oximeter data reveal apneas or hypopneas that the APAP otherwise misses?


I’d appreciate hearing about your experiences or any insights into the differences between the two.

Happy Thanksgiving.

[Deborah K.]

Comparing a sleep study to your present AHI is like comparing apples to oranges. Of course, it will be different because your apnea is now being treated.  Even a titration study is unlikely to match your present AHI because it was not done with your machine or mask. Also, you won't get a matching AHI daily with your own equipment because your sleep differs each night. Your machine reports information well, and Oscar lets us get a closer view of each night's sleep. Together they give us what we need to know.

[Rickyricardo]

The polysomnography is titrating the pressure to get to a proper AHI and they set the pressure from the titration.

If you then have low AHI on CPAP or APAP and the pressure is the same within a cm or 2 each way, then the assessment has correctly informed as to the device setting and then you can monitor the device and it should be pretty close.

My last assessment was for CPAP and came up with 8.8 as a setting, then my "expert" sleep doctor told the shop to set it at 9.2 which blew too much pressure and I set it to 8.8 myself. He got a little cross but we left it.

I got a new APAP (two actually) and they are around 8 as an average but I am fitter and lighter since the titration. I'd say the titration is great for knowing the average for CPAP pressure and then the logic of an APAP can improve on that based on its analysis.