Here is a great article by Riva Greenberg. Riva is a type 1 diabetic, and she writes articles for the Huffington Post. Her article concerns glucose meter accuracy, and other factors that influence our glucose control. The meter accuracy is important but accuracy in carb counting, and the levels of absorption of the insulin are also very important. Here is a quote from the article: "...... meter accuracy plays only a small role in the overall accuracy of insulin dosing. Carbohydrate counting and insulin absorption are the main contributors to accurate dosing, and there are enormous errors in both. Dr. Ginsberg told me the average error is only 8 percent if a meter meets the ISO standard (95 percent of the time it's within plus or minus 20 percent of a standard lab test at glucose concentrations equal to or above 75 mg/dl, and within 15 mg/dl at values less than 75 mg/dl). Comparatively, the average error in carb counting is about 20 percent and in insulin absorption about 25 percent. Hence, a lot of inaccuracy to base my dosing on. Yet, notice meter accuracy is much less impactful to my dosing accuracy. The solution, for now, is to make each of these three factors more accurate. So if we increase meter accuracy to within plus/minus 15 percent -- the new reference standard now pending FDA approva -- and I brush up on my carbohydrate counting and get a little better at calculating my insulin dose, I'll increase my chances of getting my insulin dose more accurate more of the time."
In my case the insulin absorption is a major factor. After almost 62 years of injections, and 5 years of pumping, my body is riddled with spots of scar tissue. The level of absorption is very variable because of the scar tissue. I have to change programming on my pump every time I change infusion sets. When I change sets every 3 days I never know whether my absorption will be great, mediocre or poor. It was the same with injections. Some of my scar tissue is permanent. Be sure to rotate sites to avoid scar tissue. Here is Riva's article:
Yes John things are much better. I started in 1945 without being able to test my blood, not knowing about scar tissue problems, not having a doctor who knew much about diabetes, and using insulin from cows and pigs. HA HA! It is a wonder that I survived and have no serious complications.
During the day, I'm much more consistent. I usually eat the same sort of things pretty regularly, although I've been splurging a bit lately, w/ some longer runs on my calendar, and not worrying about my weight as much. I tend to eat more at dinner, overbolus and then chill and drink beer and eat junk food to stave off the lows in the evening. Or keep dinner rolling along or whatever? I have Calorie King and a scale but don't use them all the time, again, mostly lunch because that's a bit more scientific than dinner?
I don't worry about meter accuracy that much. It seems to be pretty much in line with my CGM and A1C so it's ok w/ me. My A1C runs a bit higher than my CGM average. I don't bother d/l the data from my meter so I'm not sure if the meter is more or less accurate than the CGM, I'd guess less but, b/c of the "trends" thing, I'd sort of suspect that they'd even out, maybe the meter would have a slightly higher std dev, since I keep an eye on things and catch lots of "issues" sort of while they are happening...
Meter is used to calibrate CGM. An error on calibration affect CGM accuracy.
Think this way: if the meter measures always 20% less, your "perfect" CGM would measure always 20% less.
The problem is errors are never always the same, that would be an easy to fix drift. Bad errors are random.
GASTROPARESIS & OTHER THINGS ALSO AFFECT BLOOD SUGARS
I just became aware of a new assessment of the accuracy of 43 glucose monitoring systems. This has really good information. In general the results are encouraging and discouraging. It appears that some meters clearly could meet stricter standards, but many meters are just pretty inaccurate and have some systemic problems.
I have an Aviva Expert Brian, from what the report states, these meters seem pretty ok. My One Touch Ultra is a lost cause altogether.
I have had a lot of issues with the novo nordisk pens giving less than accurate doses. I spent three weeks thinking I was going nuts, when really my pen was giving me less than half the dose I was entering. I switched to syringes to remedy this. When my pharmacist finally convinced me to trust pens again, it happened a second time with a different pen!!!
Has anyone tried the new One Touch Verio meter?
I have the Verio IQ, just switching over a week ago. I don't have a feel for how much the accuracy is better or not (I'm a long time onetouch users). I have some things I like and don't like about it, but I'll use if for a while and see how it goes.
Richard, so nice to see that you are posting again. You are so important to this community. On the subject of meter accuracy, Dr. Bernstein has covered this issue on his last two web conferences. The webcasts can be found by googling "Ask Dr. Bernstein". He is putting pressure on all of the meter manufacturers to improve accuracy, and he gives his opinion on which meter is the most accurate. I agree though that timing of insulin action and scar tissue are as important.