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+--- Thread: Should central hypopneas count towards the AHI index? (/Thread-Should-central-hypopneas-count-towards-the-AHI-index)
Should central hypopneas count towards the AHI index? - jimbobule - 12-02-2024
Not according to the Lowenstein app...?
Their app says my AHI is 6 but Oscar and SleepHQ say more like 9, as they include central hypopneas.
RE: Should central hypopneas count towards the AHI index? - paulag1955 - 12-02-2024
Perhaps I'm being pedantic, but if the "AHI" doesn't include all the hypopneas, it's not really and Apnea-Hypopnea Index. Do they call it by some other name?
RE: Should central hypopneas count towards the AHI index? - jimbobule - 12-02-2024
(12-02-2024, 12:29 PM)paulag1955 Wrote: Perhaps I'm being pedantic, but if the "AHI" doesn't include all the hypopneas, it's not really and Apnea-Hypopnea Index. Do they call it by some other name?
Exactly. Seems there is a research paper on it..I quote a member from another site;
It seems that Lowenstein software reports AHI differently from other manufacturers. See this paper: https://hal.science/hal-03177737/document
“However, every CPAP device manufacturer uses a proprietary algorithm to detect, classify and aggregate events throughout the night to finally compute for physicians a brand specific residual AHI. The types of residual events included in the summary of nightly events vary between CPAP manufacturers essentially by including or not central hypopneas and respiratory effort-related arousals (RERAs).”
“Patients used RESMED, PHILIPS, SEFAM and LÖWENSTEIN brands. CPAP device brands were anonymized. Data from manufacturer A’s devices, which does not include central hypopneas and RERAs in residual AHI, was compared with devices from manufacturers B, C and D.”
“We suggest that scientific societies strongly recommend to CPAP manufacturers that they agree on a standardized way of reporting residual AHIs using consensual event definitions and algorithms to compute the sum of residual events.”
Manufacturer A in this paper is presumably Lowenstein.
RE: Should central hypopneas count towards the AHI index? - greatunclebill - 12-02-2024
CA's are a part of AHI. If you choose you can leave them out of your calculation to get whatever number you want based on whatever report you believe. It is your machine, your life and your decision. Be sure to discuss this with your doctor so he can offer his opinion.
RE: Should central hypopneas count towards the AHI index? - jimbobule - 12-03-2024
Just want a consistent baseline number and to understand and communicate it