Central Sleep Apnea

Dear all,

I am working on the distinction between Central Sleep Apnea (CSA) and Obstructive Sleep Apnea (OSA).

After going over a few datasets (SHHS, MESA, CFS), I see that for the AHI, hypopnea and apneas (whether obstructive or central) are taken into account.

My question is the following: how should I compute the AHIc? I see that in some cases it takes into account hypopneas and central apneas. But not all hypopneas are central, there might be obstructive hypopneas as well, no? In this case, it is not clear to me how CSA is diagnosed from the PSG raw data.

Thanks in advance, Jeremy

Also have this kind of problem. but for most articles, I see they use CAI most.

Thanks Jeremy/Chao - good questions. In addition to the overall, combined AHI variables, most datasets will have obstructive apnea and central apnea indices alone, e.g. in SHHS --

• https://sleepdata.org/datasets/shhs/variables/oai0p (obstructive apneas alone)
• https://sleepdata.org/datasets/shhs/variables/cai0p (central apneas alone)
• https://sleepdata.org/datasets/shhs/variables/ahi_a0h3 (overall AHI; all apneas + hypopneas w/ >= 3% desat)

If you look at the Calculations for these different indices you'll see that each event type has 4 components, which are individual event counts in REM/Supine, REM/Non-Supine, NREM/Supine, and NREM/Non-Supine.

Given that, you could recompute new AHI, AHIc, or other indices based on your final criteria of interest.

Thank you for your answer