Zhou Rui, Tong Qing, Zuo Chang, Song Zhi-Xin, Ma Huai-An, Yue Yu-Hong, Zhang Rui, Wang Qing-Tao
Clinical Laboratory of Beijing Chao-yang Hospital Affiliated to Capital Medical University, Beijing, China.
Beijing Center for Clinical Laboratories, Beijing, China.
Clin Chim Acta. 2014 Jun 10;433:249-53. doi: 10.1016/j.cca.2014.03.010. Epub 2014 Mar 25.
POCT for HbA1C is widely used in China. However, the lack of traceability of POCT leads to poor comparability of patient results.
The first step was the evaluation of the precision of NycoCard and DCA by using two-level patient specimens. The second step was the calibration of the central laboratory instrument G8 HBA1C Variant with samples whose values had been assigned by an IFCC reference method. The third step was the assignment of values to 50 fresh whole blood patient specimens by this calibrated G8. The fourth step was to use these 50 fresh whole blood patient specimens to calibrate and to revise the POCT instruments. The fifth step was to confirm whether these 50 specimens were required through mathematical calculations.
The low and high CVs at levels were 3.61% and 1.85% for NycoCard but 1.71% and 2.85% for DCA. The linear equation of NycoCard to calibrated G8 and that of DCA to calibrated G8 were Y=0.8530X+0.6409 and Y=0.8995X+0.3891, respectively, and the correlation coefficient for every POCT instrument was greater than 0.985. By external calibration of POCT instruments, the mean deviation detected by NycoCard was reduced from -4.0±3.4mmol/mol to 0.5±3.9mmol/mol, and that by DCA went down to 0.2±3.3mmol/mol. The minimum specimen size for the external calibration of POCT instrument was 10.
POCT measurement traceability can be established by external calibration. Using an external calibration mode improves the comparability of POCT patient results.
糖化血红蛋白即时检验（POCT）在中国广泛应用。然而，POCT缺乏可溯源性导致患者检测结果的可比性较差。
第一步是使用两级患者样本评估NycoCard和DCA的精密度。第二步是用国际临床化学和检验医学联合会（IFCC）参考方法赋值的样本校准中心实验室仪器G8糖化血红蛋白变异体。第三步是用校准后的G8为50份新鲜全血患者样本赋值。第四步是用这50份新鲜全血患者样本校准并修订POCT仪器。第五步是通过数学计算确定是否需要这50份样本。
NycoCard低、高浓度水平的变异系数（CV）分别为3.61%和1.85%，而DCA为1.71%和2.85%。NycoCard与校准后G8的线性方程以及DCA与校准后G8的线性方程分别为Y = 0.8530X + 0.6409和Y = 0.8995X + 0.3891，各POCT仪器的相关系数均大于0.985。通过POCT仪器的外部校准，NycoCard检测到的平均偏差从 -4.0±3.4mmol/mol降至0.5±3.9mmol/mol，DCA的平均偏差降至0.2±3.3mmol/mol。POCT仪器外部校准的最小样本量为10。
可通过外部校准建立POCT测量的可溯源性。采用外部校准模式可提高POCT患者检测结果的可比性。
