The Nanjing Glycated Hemoglobin Standardization Program: 2012 to 2015

Abstract

Purpose: This study aims to investigate glycosylated hemoglobin (HbA_1c), between-laboratory imprecision (%CV), and pass rates from 2012 to 2015 in Nanjing to provide evidence for improving the HbA_1c measurement.

Methods: This was a retrospective, descriptive analysis of HbA_1c levels obtained from participating hospitals in Nanjing from 2012 to 2015. The HbA_1c levels of fresh whole blood samples taken from healthy and diabetic adults were determined within 24 hours. HbA_1c levels (low level: 4.0%-6.0% HbA_1c; medium level: 6.1%-8.0% HbA_1c; and high level: 8.1%-10.0%) were grouped. Meanwhile, the target values were determined and assigned by a Level I-certified laboratory to assess the accuracy. Results as %HbA_1c and related detection information, such as methods, were collected from all participants, then evaluated after each survey part of the program.

Findings: Overall, the %CVs acquired by HPLC methods were lower than those determined by other methods. Pass rates ranged from 62.9% to 100%, depending on the HbA_1c level, and overall pass rates increased from 54.3% to 94.4% for those laboratories passing the 3 HbA_1c levels. In addition, the top-grade hospital-based laboratories had better performances than the secondary hospital-based laboratories in 2012 to 2015.

Implications: The use of accuracy-based proficiency testing with stringent quality-control management has greatly improved the performance of HbA_1c testing. The Nanjing Glycated Hemoglobin Standardization Program (NJGHSP) played an important role in this improvement by encouraging use of more rigorous quality control, participation in external proficiency testing programs, and providing education.

Keywords: EQA; between-laboratory imprecision; glycated hemoglobin; proficiency testing; quality control; standardization.