Performance of point-of-care HbA1c test devices: implications for use in clinical practice – a systematic review and meta-analysis

Regular monitoring of glycated hemoglobin subfraction A1c (HbA1c) in people with diabetes and treatment with glucose-lowering medications to improve glycaemic control can reduce the risk of developing complications [1]. In 2011, a World Health Organization consultation concluded that HbA1cat a threshold of 6.5% (48 mmol/mol) can be used as a diagnostic test for diabetes [2]. HbA1c monitoring often requires the patient to attend the health center twice: once to have blood taken and then returning to get test results and receive adjustments to medication. Point-of-care (POC) analysers are bench-top instruments that use a finger-prick blood sample and are designed for use in a treatment room or at the bed-side. They provide a test result within a few minutes allowing clinical decisions and medication changes to take place immediately. The suitability of many of these devices for the accurate measurement of HbA1c has been questioned, with some POC HbA1c test devices reported not to meet accepted accuracy and precision criteria [3]. Ideal imprecision goals for HbA1c should be coefficient of variation (CV) of <2% for HbA1c reported in % units (or <3% in SI units, mmol/mol) [4], [5], [6]. Most evaluations of POC HbA1c devices have taken place in laboratory settings [7], [8]; fewer studies have assessed device performance in a POC setting or with clinicians performing the tests [9], [10]. The only published review that has attempted to combine data from accuracy studies identified five studies covering three devices and compared correlation coefficients [11]. Systematically reporting and pooling data estimates of bias and precision between POC HbA1c devices and laboratory measurements would enable end users to assess which analysers best meet their analytical performance needs. This may be of particular importance for clinicians in primary care settings where much of the management of diabetes patients takes place. The comparison of accuracy between devices over the entire therapeutic range would need to be carried out by combining data on measurement error (bias) between POC and laboratory tests [12]. The aim of this study was to compare accuracy and precision of POC HbA1c devices with the local laboratory method based on data from published studies and discuss the clinical implications of the findings.