CPAPtalk.com

Thanks so much for this dialogue it is educating me in the reading of these
charts. Please continue. Thanks..

krousseau wrote:My question actually has less to do with what is included in the reporting than it does with the question I asked-did I do the calculation right based on the numbers given-using AI as only apnea, time in apnea only as time in apnea, and duration of apnea as duration of only apnea.

I think what you did was too complicated - I don't see why we need time spent in apnea to find the total number - but maybe I didn't understand what info you're looking for.

We have the machine's calculated index (i.e. average) for Apneas (AI) Hypopneas (HI) and the combined index (AHI). They're all great in needingu's data.

If we want to go back to the total, we just multiply each index by the number of hours used to create the index.

Total number of apneas = OAI* "total time"
Total number of hyopopneas = HI* total time

krousseau wrote:PS; The source of the discrepancy I perceive is likely due to the fact that the AI is reported from Encore Pro and the duration of apneas and total time spent in apnea is reported from My Encore-something I had not thought about on the first and second passes at this. I wouldn't be surprised if the My Encore program doesn't derive its numbers exactly the way Encore does

Right. My Encore only reads the data written (logged) by Encore Pro in the database on your computer. Encore Pro gets the data from the machine, writes what it gets on your computer, and has one way of showing you (reporting) this data. My Encore has another. It is very obvious that there is date Encore Pro logs, but doesn't report - we don't know why. Time spent in apnea is such data, and so is variable breathing. The info is written in the database created by Encore Pro, but only My Encore picks this data up and reports it to the user.

O.

I think what you did was too complicated - I don't see why we need time spent in apnea to find the total number

Absolutely! It was an exercise in looking at the report and figuring things out. We don't have to do that---normally---and am I glad! I went backwards because when I looked at the numbers-I immediately thought those are great-until I got to the duration of apneas and total time spent in apnea then I thought that can't be right! So working with the numbers I had--I tried to recalculate an AI that would fit those numbers and they went from 0.6 to 2.4-all good. It did enter my mind to do it algebraically-but that really would have been too much of a challenge for my mathematical ability. This is from a person who got to high school before figuring out where the 1 goes when you multiply it by 0. You have no idea how many teachers I drove crazy with my questions.

Now I got it.
You took the worst case scenario (20 sec for one apnea) and checked how many of those would fit into the total time spent in apnea (137 secs) and got a total of 6.85 apnea for the whole night.

Actually, that way of looking at it proves my point about the "time spent in apnea" measure

An OA index (obstructive apnea index) of 0.1 times 10.2 hours will give 1 (one) single apnea for the whole night.

There is no way that a single obstructive apnea could have lasted 137 sec.


O.

Especially if there was a range in the time listed as 5 to 20 seconds.