Hello Wendy
@SacrificedSin87,
Curiously this question came up in a different thread this morning and this concern has also been my experience in the past. The short answer seems to be that there is no answer .... sort of akin to how long is a ball of string.
As
@Leadinglights has said every meter has a 15% tolerance. And if you used just one meter and tested 5 fingers in rapid succession - while your BG is at a time when you are already very stable - then you may well get 5 different answers because of meter tolerances, strip tolerances and how stable your BG actually is from moment to moment. I'm insulin dependent and use the Dexcom G7 CGM. That generates readings every 5 mins and sometimes the 5 min dots on the graph are very level and sometimes they aren't such a "flat" line. When I had Libre as my CGM I could get 1 min interval readings and the dots were even more wobbly, but still seemingly steady BG overall.
But the key thing here is how important is it for getting identical readings rather than similar readings? In practice the 15% tolerance is workable and
@Docb, who has a long background in science and formal testing advocates that any BG meter reading should be rounded up or down to the nearest whole number. I happen to agree with that - not just because of the science or accuracy of the technology (which are valid enough reasons) - but the decimal point is disproportionately accurate in relation to what we need to know and what we do with the knowledge. So if I had 2 readings that were within 1.1 (ie just 1) I would take either answer and work with that.
By the time I've made my best calculation for the carbs I'm going to eat I already have some "guestimating" built in; for example we are told the carbs in a pear are (say) 11 CHO gms per 100 gm wt but how accurate are our scales and how ripe is the pear (the older a piece of fruit becomes the more it ripens and matures into a higher glucose content. Equally it may say on a packet of cereal that the carb content is (say) 53% but can we be certain that is exactly correct? I think absolutely not!
Then once we've translated the expected carb intake into units of insulin, we're using a guestimated conversion ratio and then applied an adjustment for planned activity (for breakfast doses) or completed activity (for evening meal) there is more guestimating. I'm not saying that it's all just a guess (so why bother at all?) - but just highlighting that despite our very best efforts there is still some uncertainty in our calculations and no point in getting too hung up on how precise a meter reading needs to be. The practical reality is that we steadily learn more and more about ourselves and normally get better at recognising when we are actually hypo or close to hypo with experience. If you have a CGM you should also increasingly lean on that to keep you safe; I keep my low alert at a safe setting of at least 5.6 and once that threshold is reached I make my informed decision about whether I need to react gently now or just pay more attention to the next reading, with a view to reacting then.
I'm not clear if you are using a Libre sensor. I read in one of the previous posts that you were concerned that your skin might react to the adhesive. Have you tried Libre yet?
However this morning's thread was from
@Duane62 who had 2 meters showing his BG as 4 units adrift on 2 different test meters; and that really can't be ignored. We ended up discussing where or how he might get a calibration check of some sort for each device and thus decide which machine to trust. This is a dialogue in progress just now.
On a different point I see that your diagnosis is steroid induced diabetes. Are you now clear about how/why that type of Diabetes is neither T1 nor T2. I'm not medically qualified, but I would say you have actually one of the T3 variants, simply because it is steroid induced. If you would like a little more information about this aspect please ask. I realise you have all sorts of other health issues and appreciate one or more of those could be far more important to be successfully managed than your Diabetes (= another pointer to being a T3 variant).
Good luck.
