Performance of Afinion HbA1c measurements in general practice as judged by external quality assurance data

Background It has been debated whether point-of care (POC) glycated hemoglobin (HbA1c) measurements methods can be used for diagnosing persons with diabetes mellitus. The aim of this study was to evaluate the analytical performance of the POC Afinion HbA1c system in the hands of the users, and to investigate which predictors that were associated with good participant performance. Methods External quality assurance (EQA) data from seven surveys in 2017-2018 with a total of 5809 Afinion participants from a POC total quality system in Norway were included in this study (response rate 90%). The control materials were freshly drawn pooled EDTA whole blood. Each participant was evaluated against the analytical performance specification of ±6% from the target value, while the Afinion system was evaluated against the pooled within-laboratory CV <2%, the between-laboratory CV <3.5%, and bias <0.3%HbA1c. Logistic regression analyses were used to investigate which factors were associated with good participant performance. Results The participant pass rates for each survey varied from 98.2% to 99.7%. The pooled within-laboratory CV varied from 1.3% to 1.5%, the between-laboratory CV varied from 1.5% to 2.1%, and bias varied between -0.17 and -0.01 %HbA1c in all surveys. Reagent lot was the only independent factor to predict good participant performance. Conclusions Afinion HbA1c fulfilled the analytical performance specifications and is robust in the hands of the users. It can therefore be used both in diagnosing and monitoring persons with diabetes mellitus, given that the instrument is monitored by an EQA system.