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+--- Thread: Session Information AHI (/Thread-Session-Information-AHI)
Session Information AHI - ICEMAN - 03-10-2016
Hi, I am Curious re the Session Information, I do shift worker, sleep at various times and or may just turn off APAP for short period. On average may have say 3 sleep sessions register for each night. I see that although each individual sleep sessions AHI may be reasonable, my actual AHI for combined 3 sleep sessions will show quite high.
It appears both Sleepyhead & Encore do this and add the individual sleep session AHI together to give a Total AHI which I cant quite understanding how this would be correct, I would have thought that Total AHI for the night " 3 sleep sessions" wouldn't be any more than the highest individual session ?
Example say sleep 1300-1500hrs AHI 2.9, then 2200-300hrs AHI 2.4 then 0320-0630hrs AHI 4.3 if add session AHI's together will give AHI Total "9.6" Yet the e the highest individual session has AHI 4.3 which would be less than 1/2 the total session accumulative AHI ? and considered treated, If some could please explain what I am missing.
RE: Session Information AHI - trish6hundred - 03-10-2016
Hi ICEMAN,
WELCOME! to the forum.!
I don't use the data-management software but, hang in there, someone will be along to help you, soon.
Much success to you with your CPAP therapy.
RE: Session Information AHI - ICEMAN - 03-10-2016
[quote='trish6hundred' pid='153507' dateline='1457668177']
Hi ICEMAN,
WELCOME! to the forum.!
I don't use the data-management software but, hang in there, someone will be along to help you, soon.
Much success to you with your CPAP therapy.
Yeah Thanks Trish
RE: Session Information AHI - Crimson Nape - 03-10-2016
Hi Iceman
Welcome to the forum.
If you take the total hours that you slept (2 hrs +5 hrs+3 hrs 10 mins as per your post = 10 hrs 10 minutes 10.16667) and divide the total number of all reported apneas by this time should be your AHI for that sleep session. The AHI is an average of all reported apneas for one sleep session, even if it is broken into segments.
AHI = Total number of Apneas / Total Session Hours
An example; if you slept for a total of 8 hours in 3 segments being comprised of 4 hours, 3 hours, and 1 hour. If you had 8 apneas only in the first segment and no other apneas for the remainder of the night, your AHI would be 1.0.
I hope this may help.
RE: Session Information AHI - ICEMAN - 03-11-2016
[quote='Crimson Nape' pid='153512' dateline='1457669525']
Hi Iceman
Welcome to the forum.
If you take the total hours that you slept (2 hrs +5 hrs+3 hrs 10 mins as per your post = 10 hrs 10 minutes 10.16667) and divide the total number of all reported apneas by this time should be your AHI for that sleep session. The AHI is an average of all reported apneas for one sleep session, even if it is broken into segments.
AHI = Total number of apneas / Total Session Hours
An example; if you slept for a total of 8 hours in 3 segments being comprised of 4 hours, 3 hours, and 1 hour. If you had 8 apneas only in the first segment and no other apneas for the remainder of the night, your AHI would be 1.0.
I hope this may help.
Thanks Crimson, think Ive go it now, each individual session AHI time is not the actual AHI for the individual session, apneas/Session hours, but the total night AHI averaged % split up over the individual sessions hours.
Cheers
RE: Session Information AHI - justMongo - 03-11-2016
I'll take a stab at it.
Sleep in 3 periods of duration T1, T2, and T3. You have an AHI number for each period AHI1, AHI2, AHI3.
The total AHI is not AHI1+AHI2+AHI3
It's ( (AHI1 x T1) + (AHI2 x T2) +(AHI3 x T3) ) / ( T1 + T2 + T3 )
RE: Session Information AHI - ICEMAN - 03-11-2016
(03-11-2016, 12:44 AM)justMongo Wrote: I'll take a stab at it.
Sleep in 3 periods of duration T1, T2, and T3. You have an AHI number for each period AHI1, AHI2, AHI3.
The total AHI is not AHI1+AHI2+AHI3
It's ( (AHI1 x T1) + (AHI2 x T2) +(AHI3 x T3) ) / ( T1 + T2 + T3 )
Thanks Mongo I thought I had it worked for while but still confused. Example:Sleepyhead shows:
Single session (1) 3hrs 41min or 3.68hrs "AHI" 0.78 is 6 apnea events
Single session (2) 4hrs 01min or 4.02hrs " AHI" 1.94 is 15 apnea events
Total session shows AHI= 2.72 and total hrs as 7.70hrs if I calculate the 21 events / 7.70 hrs = 2.72 AHI same as Sleepy head.
But cant calculate the individual sessions to match? must be averaging it on the No Events per session can any one explain ?
RE: Session Information AHI - palerider - 03-11-2016
(03-11-2016, 04:21 AM)ICEMAN Wrote: Thanks Mongo I thought I had it worked for while but still confused. Example:Sleepyhead shows:
Single session (1) 3hrs 41min or 3.68hrs "AHI" 0.78 is 6 apnea events
Single session (2) 4hrs 01min or 4.02hrs " AHI" 1.94 is 15 apnea events
Total session shows AHI= 2.72 and total hrs as 7.70hrs if I calculate the 21 events / 7.70 hrs = 2.72 AHI same as Sleepy head.
But cant calculate the individual sessions to match? must be averaging it on the No Events per session can any one explain ?
6 events/3.68 hours = 1.63 ahi
15 events/4.02 hours = 3.73 ahi
21 events / 7.7 hours= 2.72 ahi
RE: Session Information AHI - ICEMAN - 03-11-2016
(03-11-2016, 05:39 AM)palerider Wrote: [quote='ICEMAN' pid='153529' dateline='1457688097']Thanks Mongo I thought I had it worked for while but still confused. Example:Sleepyhead shows:
Single session (1) 3hrs 41min or 3.68hrs "AHI" 0.78 is 6 apnea events
Single session (2) 4hrs 01min or 4.02hrs " AHI" 1.94 is 15 apnea events
Total session shows AHI= 2.72 and total hrs as 7.70hrs if I calculate the 21 events / 7.70 hrs = 2.72 AHI same as Sleepy head.
But cant calculate the individual sessions to match? must be averaging it on the No Events per session can any one explain ?
6 events/3.68 hours = 1.63 ahi
15 events/4.02 hours = 3.73 ahi
21 events / 7.7 hours= 2.72 ahi
Yes Palerider that is what con fuses me if Sleep head shows Information session shows
Single session (1) 6 apnea events / 3hrs 41min or 3.68hrs as "AHI" 0.78 ?
Single session (2) 15 apnea events 4hrs 01min or 4.02hrs " AHI" 1.94 ?
But total of sessions 21 events / 7.70 hrs = 2.72 AHI
RE: Session Information AHI - DariaVader - 03-11-2016
(03-11-2016, 06:48 AM)ICEMAN Wrote: 6 events/3.68 hours = 1.63 ahi
15 events/4.02 hours = 3.73 ahi
21 events / 7.7 hours= 2.72 ahi
Yes Palerider that is what con fuses me if Sleep head shows Information session shows
Single session (1) 6 apnea events / 3hrs 41min or 3.68hrs as "AHI" 0.78 ?
Single session (2) 15 apnea events 4hrs 01min or 4.02hrs " AHI" 1.94 ?
But total of sessions 21 events / 7.70 hrs = 2.72 AHI
you are leaving the middle session out of your calculation and it has a higher AHI and has skewed the average (which is for 3 sessions and not 2)