Re events per hour and ahi

[Novello1234]

Hi I have resmed 10 for her what is the difference with events per hour and  ahi also does the events per hour need to match the ahi

[Gideon]

Welcome to the forum

Read "Understanding sleep apnea" in the first link in my signature.  The send article explains your question.

AHI is a sum of OA, CA, and H events divided by the number of hours.

[Novello1234]

Welcome to the forum

Read "Understanding sleep apnea" in the first link in my signature.  The send article explains your question.

AHI is a sum of OA, CA, and H events divided by the number of hours.

Thank you not able to find link

[Gideon]

click on "New to Apnea? Helpful tips to ensure success"  which is in my signature (1st of 2 links)

[PaulaO2]

I think events per hour vs AHI is a difference in math. I think.

Events per hour are all the events put together then averaged by the number of hours. So 16 events during 8 hrs is 2.

AHi takes each individual part, does the math, then adds them together and does more math. But it uses minutes, not hours and is more accurate because it doesn't round up. There may be only a slight difference between the two. Say 2.3 vs 2.2

I think.

[sptrout]

I think events per hour vs AHI is a difference in math. I think.

Events per hour are all the events put together then averaged by the number of hours. So 16 events during 8 hrs is 2.

AHi takes each individual part, does the math, then adds them together and does more math. But it uses minutes, not hours and is more accurate because it doesn't round up. There may be only a slight difference between the two. Say 2.3 vs 2.2

I think.

Paula,

I tried to test how AHI is computed and the only way that I could make the math work was to divide the total number of "events" by the number of "hours" and fraction of an hour. This method gave me results identical to what SH was showing. 

OP, a couple things to remember: 1) You have to depend on your machine keeping correct track of the number of SA "events", and 2) the number of hours used in the calculation is really the total hours from the moment you turn the machine on to the moment you turn it off - - the machine cannot tell if you are asleep or not. Therefore, if you have trouble sleeping some nights and are just laying there staring at the ceiling, your AHI will improve the longer that you are awake (no events when awake while increasing the time the machine "thinks" you are asleep). Very easy to see this unavoidable error: say you wake-up at 5AM for a bathroom trip. You turn your machine off and it will display the calculated AHI upto that time. You come back to bed a couple minutes later and turn your machine back on, but instead of falling back asleep you just lay there until say 7AM and then turn off the machine to get up. I promise you that the new AHI displayed will be a little better than the 5AM number. No events when awake, but the machine assumes that you were asleep between 5-7AM. The best possible AHI "0" will always happen if you are awake all night and not sleep a second. Naturally, it is possible to get a "0" and really sleep all night.

[zonk]

Hi I have resmed 10 for her what is the difference with events per hour and  ahi also does the events per hour need to match the ahi

Events per Hour is AHI for last night or previous day (midday to midday) 
AHI which is displayed at the bottom part of the sleep report is the AHI for the period selected, default set to "1 Month" 
If "period" changed  to "1 Day", the AHI displayed will match the "Events per Hour" which is displayed at the top part of the sleep report. Whenever the machine unplugged, period revert back to "1 Month" 

AirSense 10 instructions and how to ask for the clinical manual via email http://www.apneaboard.com/resmed-airsens...setup-info