Comparison of Three Different EDTA Tubes for HbA1c Measurement

Objective: In clinical laboratories, it is aimed to minimize the sources of error in pre- and postanalytical processes along with the analytical process. The most common errors are pre-analytical process errors, which are frequently encountered during sample collection. For quality and reliable test results, the validation of sampled tubes is important and helps reduce pre-analytical errors. This study aimed to compare the HbA1c results of the K2-EDTA BD Vacutainer tube that we currently use for HbA1c measurement in our laboratory and two different brands of EDTA tubes from another manufacturer. Methods: Blood was drawn simultaneously from 29 patients with diabetes mellitus, 20 with prediabetes, and 29 apparently healthy individuals into three different EDTA tubes (K2-EDTA BD Vacutainer, K2-EDTA Samplix, and K3-EDTA Vacuette). The bias% was calculated for clinical significance and evaluated according to the CLIA bias% target (1.5%). Results: The median (interquartile range) values of HbA1c levels of K2-EDTA BD Vacutainer, K2-EDTA Samplix, and K3-EDTA Vacuette tubes were the same and were 6.0% (5.5-7.6). There was no statistically significant difference between the HbA1c results of the BD Vacutainer, Samplix, and Vacuette tubes (p=0.980). The calculated bias% values were <0.3%. Conclusion: There was no clinically or statistically significant difference between the HbA1c results of K2-EDTA BD Vacutainer, K2-EDTA Samplix, and K3-EDTA Vacuette tubes, and they were observed to meet the performance target. We believe that these 3 different brands of tubes can be used simultaneously and safely interchangeably, regardless of the distinction between K2-EDTA and K3-EDTA in HbA1c measurement.