Meter Accuracy vs Lab Test result

[zx10pilot]

I can fully appreciate there is a fairly wide (+/- 10%) margin of error for portable (hand held) meters and they are a bloomin marvellous creation... however... I suspect my Glucomen LX meter is a wee bit further out than that.
Had a blood test on Monday and pricked my finger immediately after and tested (couldn't use arm blood as nursey had covered it immediately).

My meter showed 7.7 mmol/L (and 20 minutes before showed 6.8 as I had to drive there).
However, the lab test glucose level came back as 5.1 mmol/L!

That a whopping 2.6 mmol/L different (or 50.9%!)... is it really possible for blood in my arm to contain such a different blood glucose level?

The HbA1c came back as 38 mmol/mol (happy days). Also had cholesterol checked... oh dear... that's a different story
My HbA1c has always seemed low compared to my average readings on the meter.

So, I have a consultant appointment on Friday so is it worth mentioning this difference to him? How do I go about getting a new meter if this one is fubar? Is it my choice or do I have to use whatever is "recommended". Thanks for any advice or guidance.
zx

 

[trophywench]

If my consultant were to write to my GP and say - Mrs C needs to use this meter, not that one - then your GP will have to prescribe the relevant test strips - so definitely ask him! Personally at Rugby St X though - we ask our DSN and they deal with it - same as changes in 'brands' of insulin.

 

[mikeyB]

Well, zx, the answer to your question is yes, it can be so different, you have discovered the emperor's lack of clothing. It would probably be similar whichever kit you used. Libre users like me accept this difference, specially when recovering from a hypo, and I switch to using fingerprick, knowing that to be more accurate in rapid changes, but I know it's still not a true record. Near enough, though.

If the nurse had put a drop of venous blood on your test strip, it wouldn't have given the same score anyway because of the different assay method.

You might wonder where all this leaves you, but you might as well stick to the machine you've got (but check the calibration) because it seems to have served you well.

 

[zx10pilot]

Thanks Mike, that makes sense, and explains why the Libre does give slightly different readings but still doesn't totally explain the big difference between my average meter reading and the "equivalent" A1c reading.
I'll carry on with my meter for the moment then but I will have a chat with consultant and see if he has any control strips I can try.
He might even give me a new meter if there's some doubt?

 

[mikeyB]

Sensible plan, for sure. Always worth blagging new kit🙂