Method for the improving of point-of-care HBA1c results harmonization

Abstract

Objective To establish a new traceability pathway of point-of-care testing (POCT) of HBA1c by using commutable quality controls, in order to improve the accuracy of POCT HBA1c and the harmonization of testing results with those of central laboratories. Methods The study was about measurement traceability. Human frozen whole blood samples with IFCC assigned values were used to calibrate the G8 HBA1c Variant in June, 2013. According to the CLSI EP9-A2-IR guideline, 50 patient samples and 2-level commercial QC samples were then analyzed by G8 system and DCA Ventage system. The best fitting curves for fresh patient samples and the commercial QC materials were established separately. The patient results tested on the DCA Ventage were modified and verified. Paired t-test and Passing Bablok linear regression were used. Results The linear equation of DCA/G8 before calibration was Y=0.899 5X+ 0.389 1(R2=0.991 0). Calibration by fresh patient samples reduced the mean bias of DCA/G8 from -0.40%±0.34% to 0.00%±0.29%. Calibration by QCs reduced the mean bias to 0.15%±0.29%. The linear correlation established by quality controls was stable, which made the bias was lower between DCA and G8 in the consequent six runs. Conclusions The accuracy and the traceability of POC testing could be realized by using commutable QC materials traceable to IFCC assigned values. Through this method, POC testing can become more comparable to the results of clinical laboratory HBA1c instruments.(Chin J Lab Med, 2015, 38: 310-312) Key words: Hemoglobin A, glycosylated; Point-of-care systems; Reproducibility of results