Background: This study aimed to evaluate whether the quality performance of clinical laboratories in China has been greatly improved and whether Internal Quality Control (IQC) practice of HbA1c has also been changed since National Center for Clinical Laboratories (NCCL) of China organized laboratories to report IQC data for HbA1c in 2012.
Methods: Internal Quality Control information of 306 External Quality Assessment (EQA) participant laboratories which kept reporting IQC data in February from 2012 to 2016 were collected by Web-based EQA system. Then percentages of laboratories meeting four different imprecision specifications for current coefficient of variations (CVs) of HbA1c measurements were calculated. Finally, we comprehensively analyzed analytical systems and IQC practice of HbA1c measurements.
Results: The current CVs of HbA1c tests have decreased significantly from 2012 to 2016. And percentages of laboratories meeting four imprecision specifications for CVs all showed the increasing tendency year by year. As for analytical system, 52.1% (159/306) laboratories changed their systems with the change in principle of assay. And many laboratories began to use cation exchange high-performance liquid chromatography (CE-HPLC) instead of Immunoturbidimetry, because CE-HPLC owed a lower intra-laboratory CVs. The data of IQC practice, such as IQC rules and frequency, also showed significant variability among years with overall tendency of meeting requirements.
Conclusion: The imprecision performance of HbA1c tests has been improved in these 5 years with the change in IQC practice, but it is still disappointing in China. Therefore, laboratories should actively find existing problems and take action to promote performance of HbA1c measurements.
Keywords: HbA1c; clinical laboratory; coefficient of variation; diabetes; diagnosis; imprecision; internal quality control; quality specification.
© 2016 Wiley Periodicals, Inc.