Libre time in range

[curlygirl]

I was wondering if anyone knows whether the time in range and other data on the libre is calculated from all the data eg scans as well as readings between them. I was thinking I sometimes scan a lot if low or high, but this would mean lots of low scans or lots of high scans are registered and when just middle area blood sugar less scans are done. I think the data the libre produces for time in range and average blood would come from all the data it has. Was just curious if anyone knows whether that is the way it is calculated...

 

[Bruce Stephens]

I was wondering if anyone knows whether the time in range and other data on the libre is calculated from all the data eg scans as well as readings between them.

My guess is it's the same data used for the graphs, so 4 values per hour, and not influenced by how many scans you do (except that there can be gaps if you don't scan enough and leave over 8 hours without scanning). But I'm guessing (plausibly, I hope).

 

[Robin]

My interrpretation is the same as @Bruce Stephens 's. It’s TIME in range, not number of scans in range. So the Libre will calculate it from the graph and add up the number of hours or minutes you were within the set parameters.
My Libre will tell me I was below my lower target for x number of minutes, even if I didn’t scan at all during that time because I was asleep.

 

[barrym]

As above! It is, as far as I can see, from a summation of all 'calculated' 5 minute readings. I only do a small number of scans as I use a 3rd party CGM app alongside to show me what's going on. If it relied on scans It would be very inaccurate.

edit: Bit of brain fade - should be 15 minute readings. I've been reading a lot about the 'other' three CGMs that are now on offer and getting all the times mixed up . You can check this from looking at the data download from LibreView.

 

[curlygirl]

Low readings in the night when not scanned does get listed so yes it does appear to be that it is all the data equal with not a skewing of results by more scans at low or high periods. Just wondered how it was worked out. Thanks

 

[Rob Oldfield]

I did send them an email a couple of years back asking for more detail on the calculation method and, unsurprisingly I guess, they proved to be quite protective of that.

 

[Inka]

Agree with @Bruce Stephens I imagine it’s largely if not wholly based on the same data they use for the graph, so the number of times you scan wouldn’t matter. After all, the Libre knows your blood sugar whether you scan or not.

 

[Bruce Stephens]

Agree with @Bruce Stephens I imagine it’s largely if not wholly based on the same data they use for the graph, so the number of times you scan wouldn’t matter. After all, the Libre knows your blood sugar whether you scan or not.

Provided you scan at least once every 8 hours, that is. (Which I'm apparently not quite doing at present.) I'd argue for every 15 minutes because the specifications say the memory is 8 hours, with glucose reading stored every 15 minutes. (It's entirely possible that each reading is an average or something of more readings.)