Differences between SleepyHead and ResScan stats

[Iowamv]

I'm finding that most days SH and ResScan give me slightly different numbers for total sleep time. Known issue? Last night, ResScan says 7:36, but SH says 8:20. I think SH is correct. I did adjust the mask a bit, which led to turning the machine off and on a few times over a period of 10 minutes prior to finally turning out the lights. But I went to bed at 10pm, and got up at 6:26.

Does ResScan have some algorithm for tossing out data when it thinks you are not yet asleep? If not, what might cause this substantial difference?

I just noticed (for the first time) that the stats were slightly different too-- which makes sense, since total sleep time forms the denominator for them.

ResScan: AHI=.3, CA=.2, UA=.1
SH: AHI=.24, CA=.24

Are these kinds of differences common?

[jedimark]

I'm finding that most days SH and ResScan give me slightly different numbers for total sleep time. Known issue? Last night, ResScan says 7:36, but SH says 8:20. I think SH is correct. I did adjust the mask a bit, which led to turning the machine off and on a few times over a period of 10 minutes prior to finally turning out the lights. But I went to bed at 10pm, and got up at 6:26.

Does ResScan have some algorithm for tossing out data when it thinks you are not yet asleep? If not, what might cause this substantial difference?

I just noticed (for the first time) that the stats were slightly different too-- which makes sense, since total sleep time forms the denominator for them.

ResScan: AHI=.3, CA=.2, UA=.1
SH: AHI=.24, CA=.24

Are these kinds of differences common?

Part of that is due to SH rounding to an extra decimal place, and the other part is SleepyHead ignores very short sessions, so if something was flagged during them it will be dropped. ResScan probably counts those.

Edit: As for sleep time, the same issue applies.. SleepyHead will not bother to load short sessions, so it will not add them to the hours tally.

[Iowamv]

Thanks, Mark. It seems the issue is ResScan. The ResScan graphs clearly show me going to be around 9:30pm and getting up at about 5:30am this morning. SH correctly reports that I got almost exactly 8 hours of sleep (or rather, that the machine was on for 8 hours). SH notes the one CA event as I was waking up, and so my AHI for the night was .12. ResScan also notes that one CA event, but reports my usage as 7:20, and my AHI as 0.00. So my ResScan summary stats don't match up with my ResScan graphs.

[Pugsy]

When or did you change the clock on the S9 for DST?

[Iowamv]

Well shoot. Pugsy, I'm sure you've got it. I think I changed Sunday evening before going to bed. So my report for that night is off by 13 minutes. My report for last night was off by 42 minutes. I checked a handful of earlier dates, and they all match up. So I screwed something up when I changed the S9 clock.

Now what should I do?

[Pugsy]

So I screwed something up when I changed the S9 clock.

Now what should I do?

Don't do anything. If I remember right my sleep times were off for a couple of nights when I changed my clock on my S9 last fall and last spring. ResScan can't seem to get it figured out immediately.
After a couple of nights things returned to normal with me not doing anything other than the original time change.
I know for sure one night was totally messed up in ResScan and I am pretty sure a second night was also messed up.

Give it a couple more nights and see if things straighten out on their own. I am thinking they will.

[Iowamv]

For the record: once again, Pugsy nailed it right on the head. This morning I got up and found that SH and ResScan are perfectly in sync. Where would we be without you, Pugsy?! Thanks.