BACKGROUND: In 2009, we investigated the conformance of 8 hemoglobin A1c (Hb A1c) point-of-care (POC) instruments. Since then, instruments have improved and new devices are available on the market. In this second study, we evaluated the performance of DCA Vantage, Afinion, InnovaStar, Quo-Lab, Quo-Test, Cobas B101, and B-analyst Hb A1c POC instruments.
METHODS: Clinical and Laboratory Standards Institute protocols EP-5 and EP-9 were applied to investigate imprecision, accuracy, and bias. We assessed bias using the mean of 3 certified secondary reference measurement procedures (SRMPs). Assay conformance with the National Glycohemoglobin Standardization Program (NGSP) certification criteria was also evaluated. Interference of common Hb variants was investigated for methods that could work with hemolysed material.
RESULTS: The total CVs for all instruments, except for the DCA Vantage at a high Hb A1c value, were ≤3.1% in SI units and ≤2.1% in Diabetes Control and Complications Trial (DCCT) units. Afinion, DCA Vantage, B-analyst, and Cobas B101 instruments passed the NGSP criteria with 2 different reagent lot numbers. Quo-Test, Quo-Lab, and InnovaStar instruments had a negative bias compared to the mean of the 3 SRMPs and failed NGSP criteria. Most of the common Hb variants did not interfere with the investigated instruments, except Hb AE for the Cobas B101.
CONCLUSIONS: Afinion, DCA Vantage, Cobas B101, and B-analyst instruments met the generally accepted performance criteria for Hb A1c. Quo-Test, Quo-Lab, and InnovaStar met the criteria for precision but not for bias. Proficiency testing should be mandated for users of Hb A1c POC assays to ensure quality.
- Received for publication March 10, 2014.
- Accepted for publication May 15, 2014.
- © 2014 American Association for Clinical Chemistry