[kid_fears99]

I've noticed recently that my UltraSmart gives me different readings depending on which finger I test on. This may sound absurd, but my right ring finger always tests about 40-50 points below my left ring finger. For instance, last night before dinner I tested five times on five different fingers and got results ranging from 190 to 287. I always wash and completely dry my hands before I test, my meter is almost new, and this is not the first time this has happened. I usually take an average of the results and use that for my correction factor. Has this happened to anyone else?

[disgusted]

Originally Posted by kid_fears99

I've noticed recently that my UltraSmart gives me different readings depending on which finger I test on. This may sound absurd, but my right ring finger always tests about 40-50 points below my left ring finger. For instance, last night before dinner I tested five times on five different fingers and got results ranging from 190 to 287. I always wash and completely dry my hands before I test, my meter is almost new, and this is not the first time this has happened. I usually take an average of the results and use that for my correction factor. Has this happened to anyone else?

it's strange but I have had this happening several times noone could explain to me either. I even asked the doctor and she didn't know. Maybe its like when they check your blood pressure and both arms have different results. Do you hands/fingers feel like they asleep often? If so it might have to do with that. Am sorry am not of much help just wanted to say you are not the only one this has happened to. All the best to you

[JediSkipdogg]

You need to keep in mind that BG meters are allowed a 20% accuracy range. Read this for more info on an experiment I conducted. Blood Glucose Meter Comparison
And all 4 of those tests were done with the same sample of blood...

Also, remember, blood takes a while to circulate through all parts of the body. Therefore one finger may get it sooner than another. Heck, even on the same finger, a different vessel may get fresh blood 5 minutes sooner than another one.

It's just something we have to live with for now until better technology comes along. Which at this time I don't see any.

[Cyborg]

People read my middle finger differently

[Tor]

I switched from One Touch Ultra to Accuchek Compaq because the Onetouch reading were all over the map, even when I bought a new meter. My Accuchek has been faithful and reliable, even when testing on different fingers I rarely get more than a plus/minus 10 point variation.
However, I think some people with poor blood circulation will get widely different results regardsless of what meter they use.
Tor

[rzrbks]

Cyborg

People read my middle finger differently

So, you like King Aiken Drum work under the banner of the Digitus Impudicus?

[Cyborg]

Read between the lines baby...

[CindyA2]

I use the One Touch Ultra and have discovered a difference in the reading between my first finger and ring finger. I sometimes have trouble getting suffiecent blood on my first finger and am wondering if that is the cause.

Anyone else have abnormal readings when the bood doesn't seem to "absorb" correctly on the strip?

[Noturningback]

I have a one touch ultra mini and just received two different results.

Reading 1: index finger 128
Reading 2: middle finger 140
Reading 3: index finger 127

All of them were on my left hand and I took them one after another. It's not a massive difference but, significant enough.

Things that make you go hmmmmmm. I am going to call them and see what they say.

~Danielle

[Noturningback]

I called them and after many minutes listening to Vivaldi, I received the same answer JediSkipdogg gave you. I didn't doubt the answer. I just was curious to see what they would say when I called them.

Yes, I have too much time on my hands.

[REDLAN]

I think there are several issues at play...

1) delusions of precision. In the modern digital age we get numbers instead of dials, and our meters can even do decimal points. It's down to marketing, I'm afraid. A meter that boldy states 5.7 or 127 is much more impressive than one that just says 6 or 130. It's not just glucose meters, - body fat monitors, BP monitors, weighing scales, voltmeters etc. etc. have readouts far in excess of the meters level of precision.

2) There's no such thing as a blood glucose level. Blood glucose levels vary from minute to minute, and from body part to body part. The reason is because blood glucose levels are dynamic - the actual level depends on the rate at which glucose is delivered to the tissue, as compared to the rate it is utilised. Differences in fingers can be explained by different flow rates - a finger with a slower flow of blood, but simillar glucose needs will have a lower blood sugar. Similar problems are encountered in BP measurements. Right and left arms are usually different - it's all down to differences in artery diameter.

3) sample error/variation. CindyA2's question is an emphatic yes. Difficulty obtaining a sample will most definitely alter the results. A big influence on meter readings is sample temperature. The hotter the sample, the faster it will react on the test strip and the higher the reading. Increasing the temperature by 10 C (18 F) will double the speed of the reaction. Body temp is around 36C and room temp is around 20C. Take too long, get a smaller drop than usual, have cold hands, and your meter will read a lower blood glucose. Test on a hot day and your reading will be higher than usual.

The answer is to take account of the level of imprecision in your regime. I wouldn't assume that a glucose meter has a greater accuracy than +/- 2.0 mmol (36 mg/dl).

It's one of the reasons I only count in multiples of 5g when measuring carbs. This is at the limit for which I can accurately measure the amount of carbs in a food. In the UK food legislation allows manufacturers a great deal of leeway in the accuracy of their food labels. It may say 21.1g on the label, but that measurement may come with +/- 20% error margin.

[xMenace]

Originally Posted by REDLAN

The answer is to take account of the level of imprecision in your regime. I wouldn't assume that a glucose meter has a greater accuracy than +/- 2.0 mmol (36 mg/dl).

You might want to rethink this one. I think a percentage may be more meaningful such as +/- 20%.

e.g. a reading of 3.2mmol/l would not likely be off by 2.0 where a reading of 25.5 could very well be.

[cheryl]

For me, my left hand is always sweeter then my right hand.....I am always higher on my left hand.........most of my fingers will be within 10-15 points of eachother, but I notice my left side can be 40-50 pts higher then my right side, So I don't test on my left side when checking bg's after meals...because I might think I am way high LOL


Cheryl

[REDLAN]

You might want to rethink this one. I think a percentage may be more meaningful such as +/- 20%.

it's a good point

Meters are more accurate for the range they are calibrated i.e. below 10 (180). There are however different kinds of accuracy.

1) Accurate to a gold standard. I grabbed my ultrasmart bottle and had a look at the control sample range, which is 5.4 to 7.2mmol/l (98-131) or +/- 0.9 mmol (16.5) or as a %age +/- 16%. This is for a calibrated control sample, made in a lab, and not squeezed out of your finger (with all the sample error problems above). The 20% error number comes from testing meters against the results obtained from venous blood drawn in the clinic. If we assume this is correct then we get +/- 1.3 mmol (23 mg/dl) for normal blood glucose ranges with good sampling technique. Gold standard accuracy is about asking whether my 6.3 is really a 6.3. What we find is that 6.3 means a blood sugar that in reality could be as little as 5.0 to as high as 7.6.

2) Consistency. Are the meter readings consistent? If I measure the sample over and over again do I get the same result? On a calibrated sample meters do very well. Run a calibrated sample over and over again, and your meter will read the same result with a max variation of +/- 0.1 mmol/l (1 mg/dl), which sounds really good. Measure yourself and a big variation suddenly appears sometimes even when you measure the same drop of blood. The poster who had 128 from one finger and 140 from another is looking at a sample variation of about of +/- 10%. Translate this to normal BG's and for your 6.3 you get a range of 5.7 to 6.9, so you can be pretty certain that 8.0 is higher than 6.0, but not so certain 7.0 is higher than 6.0.

I think that's alll as clear as mud

[Scrabblechick]

My left thumb is usually lower. My right pinkie is the highest, generally. Go figure! My endo said I could take three different samples, average the totals and still be +/- 20 percent. Heh.