What is the difference (Apnea vs AHI)

[macheta]

The Oscar Overview tab has multiple graphs. One of them is Total time in Apnea and another one is AHI. What is the difference? They both follow the same pattern but are slightly off. For example, last night my total time in apnea was 2:55 with an AHI of 2:22.

[WhyMe]

AHI is an abbreviation for Apnea and Hypopnea Index - it shows how many events you had on average per hour- in other words, total events for the measured time period divided by the number of hours involved.

Total time in apnea is just that - you had a certain number of apnea’s, but they all last different amounts of time. This tells you the total time the machine measured you as not breathing.

The fact that the numbers look similar in your case is pure coincidence.

[macheta]

Thanks for the explanation. I thought the time was in hours not minutes.

[Sleepster]

The Oscar Overview tab has multiple graphs. One of them is Total time in Apnea and another one is AHI. What is the difference? They both follow the same pattern but are slightly off. For example, last night my total time in apnea was 2:55 with an AHI of 2:22.

AHI is average number of events (apneas or hypopneas) per hour, so in your case it was 2.22. So, for example, if you slept for 9 hours and had 20 events, we would divide 20 events by 9 hours and get approximately 2.22 events per hour.

To count as an event, it must last at least 10 seconds. In OSCAR you can actually see how long each event lasts. Obviously, events that last longer are more of a concern. Like, if you had an apnea that lasted 60 seconds that's worse than if it had lasted only 10 seconds. But they score the same in the AHI.

It is therefore helpful to know the total time in apnea. In your case it was 2 minutes, 55 seconds. I find it more helpful to simply look at how long each event lasts, hunting for those that might be significantly longer than 10 seconds.