Data how much how often

All,
I have been recording and reading my data card since I started cpap almost three years ago. I have used the data from time to time to diagnose issues with pressure or to see if a new mask works well. All this time, i have been lucky to have low leak rates and very low and hypopneas numbers, etc. I am thinking of stopping my weekly detailed data downloads on my third year (Dec 17th). I plan on reading my card from that point onward for issue tracking only and maybe compliance type data.

I am curious how often people read their data. How many days can the smart card hold compliance data. I know that I can only keep a week of detailed sleep data. I was thinking of a monthly reading to keep the usage data in case I need it for some future reason (insurance or new health care law requirement).

In the manufacturing world there is a system called statistical process control. The practice is to measure a particular characteristic on something like 5 consecutive parts out of every 50 parts made. The idea is that with the periodic checks you compare the averages of each set of 5 and that will give you a picture of long term trending. Measuring 5 consecutive parts gives you a good picture of part to part variability.

You might think about adopting something similar, like check the detail data for 7 nights running about every 6 to 10 weeks. That way you cover the variability of an entire week of daily life, and then can see if things are changing over the long term. It's best, but not critical, to be consistent, like always do it Sunday through Saturday or whatever, and always the same number of weeks apart. I haven't gone to that approach myself yet, but I'm sure I will before long. Keeping the data for every night for months on end is getting old and doesn't tell me anything I didn't already know.

I think your idea makes perfect sense after 3 years.

I'm glad you asked that question. My situation is a bit different since I'm monitoring my husband's therapy without much actual input from him, but I can really tell from observing him on a daily basis how he's doing. But it was 3 yrs in Sept and I still download his data every morning!! I'm telling myself that on Jan 1,2012 I will only look at the data weekly but I told myself that last year too!

I was checking my data every day using the Respironics Encore Viewer software, because I could only see 7 days at a time and it gave me the ability to see what was happening each day as well as over the week. Now, however, I use the SleepyHead software that can give me daily information, and averages over however long I choose. It also has the wave-form data, so I can look real close at what went on during a particular night - much more useful than the Encore Viewer information. I am just waiting for the ability to print out the wave-form data from SleepyHead, and the information will be complete. Currently, I can save a screen shot and print that out, so all is not lost!

So, now I do not check my data on the machine every day (started doing that when I didn't have the software). I don't mind if I miss a day of checking the data in SleepyHead. I am getting to know whether I have had a good or a not so good night without doing the daily check. I guess the bottom line is to do what you are comfortable doing.

I don't download very often at all, but I pull up the sleep report screen;
and write down my hours,average pressure,leak rate, AHI, and CI for each night
(as well as what mask I wore) in a little notebook I've kept since July 2010.
I started out with just hours and AHI, and added data as I found out how to look at it.
My notebook pages look like a little spread sheet; and I show it to my doctor a couple of times a year.

Thank you for the advice. I think I will download every two months starting on jan 2012.