(03-08-2016 07:45 AM)DeepBreathing Wrote: Not sure which particular variation you mean - there are quite a few.
ResScan reports the percentage of days with usage > 4 hours. I'm not sure what Sleepyhead reports for compliance.
ResScan truncates an index to one decimal place before using it in a calculation. Hence there are substantial rounding errors. SleepyHead reports to two decimal places and I suspect it doesn't truncate at all in its calculations. The outcome of this is that the SleepyHead numbers usually add up pretty closely while the ResScan will show cumulative errors over a large number of nights.
I think the fact that Resmed aren't too fussed about these errors is an indication that we shouldn't get too hung up on the exact numbers. They are an important indication of efficacy, but they are no the be all and end all.
I have attached some more objective evidence of the measurement accuracy issue maybe there is something I am doing wrong with the software
I timed three night on my cell phone and there is a contestant 2 second deviation in rescan and more in sleepy head that will effect the compliance report.
in addition; on two of the nights the AHI and total time don't agree insight the Sleephead tool. On two different sleepy head tabs Daily and the Statistics screen give different numbers
see attached data from screen shots.
Rounding does explain some of it, but there is larger issue here that rounding