Table 1.

Summary of variant Hb effects on Hb A1c results by method.

Hb traitA1c 2.2 PlusVariantDCA 2000Tina-quant
CamdenND1Falsely low2No effect3ND
D Los AngelesNo effectFalsely lowNo effectNo effect
EFalsely lowNo effectNo effectND
G PhiladelphiaFalsely high4Falsely lowNo effectNo effect
GradyNo effectNo effectNo effectNo effect
HopeNo effectFalsely highNo effectNo effect
J BaltimoreFalsely lowFalsely lowNo effectNo effect
RaleighFalsely highFalsely highNo effectND
RussNo effectNo effectNo effectND
  • 1 ND, not determined.

  • 2 For the effect of a Hb variant to be considered falsely low, the average difference of the percentage of Hb A1c between the test and comparative methods had to be less than −1%.

  • 3 For there to be no effect of a Hb variant, the average difference between the test and comparative methods had to be within ±1%.

  • 4 For the effect of a Hb variant to be considered falsely high, the average difference between the test and comparative methods had to be >1%.