Performance evaluation of HbA1c measurement systems with sigma metric for 1066 laboratories in China

Abstract Background This study aimed to evaluate the performance of HbA1c measurement systems quantitatively with sigma metric and promote the quality improvement. Methods 1066 laboratories enrolled external quality assessment (EQA) and reported their internal quality control (IQC) data for HbA1c in 2017 were included in this study. The bias and coefficient of variation were collected from EQA and IQC program designed by the National Center for Clinical Laboratory. The σ values was used to assess the performance of HbA1c, and combine Westgard Sigma Rules™ to select proper quality control rules in every laboratory. Results Totally, There were 388,190,185,100,59,55,89 participants used Bia-Rad HPLC, TOSOH G7/G8, ARKRAY HA8160/8180, HUIZHONG MQ-2000/2000PT, Roche, Primus HPLC and “Others” system, respectively. “HUIZHONG MQ-2000/2000PT” group had the smallest variation of bias. 56.19% (599/1066) of laboratories met bias criterion and 55.63% (593/1066) satisfied imprecision criterion. However, sigma metrics indicated that 80.21% (855/1066) of 1066 laboratories needed to improve their performance of HbA1c. Moreover, “TOSOH G7/G8” group had the highest constituent ration of σ ≥ 3. Conclusions The analytical quality of HbA1c in most laboratories need improving. Laboratories should pay more attention on the performance of HbA1c, and EQA organizers in China should improve evaluation criteria and push standardization work for HbA1c.