Never trust a single lab test

The real take home message is not to test those instant A1c tests.

They've always been extremely inaccurate. A1c Now had a range of plus or minus .5% (i.e. if you were 6% at a lab their test could return anything from 5.5% to 6.5%.) That renders them useless for anyone who uses a meter and has a pretty good idea of how they're doing already.

What is a real problem is how doctors don't seem to understand that the margin of error of the instant tests is much wider than the lab tests. The companies are promoting them as "in office" tests to replace the labs.

Bottom line: It increases earnings for the practice at the expense of the patient who gets a highly inaccurate reading.

I don't think most insurance will pay for a retest of A1c unless perhaps it's way out of line, say 12 when you're expecting a 6.

Even lab A1cs can vary a lot. In a Joslin study, I once had a 6.0 and 6.4 from the same blood sample, sent to two different labs.

People need to understand that A1cs are simply estimates. The important thing is patterns. If you're 6.0 one time and 6.2 the next time, it doesn't mean much, especially if the next time you're 5.8. If you're 6.0, then 6.2, then 6.5, then 6.9, it suggests your control is worsening.

I've heard too many people moaning if their A1c is 0.2 higher or rejoicing if it's 0.2 lower.

I was having some doubts about the lab tests as an absolute my Dr. uses 2 different labs, from one my Lipids are better but my HbA1c is worse and from the other my A1c is better and my lipids worse.  This is not one test but 2 from 1 lab and 4 from the other and they are intermixed.  I was a senior Test an Measurements Technologist in my career, different field, and worked with worse case accuracy of 0.001 +/- one count but usually 0.0000001 +/- one count, but also down to the nano and pico  levels. The +/- 20% of our glucometers is bad enough but 10% for a lab environment is criminal.