Validation of the LumiraDx for the measurement of HbA1c for Diabetes diagnosis and monitoring

Abstract

Introduction: South Africa has a high number of people living with diabetes, many of whom are either not diagnosed or are poorly controlled. Diabetic control can be monitored using HbA1c. Several studies have shown that point-of-care (POC) testing of HbA1c improves patient management and glycaemic control. Aim: This study aimed at evaluating the performance of the LumiraDx POC analyser (LumiraDx UK Ltd, London, UK) for the measurement of HbA1c for diabetes diagnosis and monitoring. Methods: The investigation was conducted in two phases: an initial laboratory evaluation followed by a clinical evaluation. In the laboratory phase, we assessed precision, linearity, accuracy, and lot-to-lot variation. The clinical phase involved method comparison analyses to evaluate the interchangeability of the LumiraDx HbA1c test with a laboratory reference method (Bio-Rad Variant™ II Haemoglobin Testing System (Bio-Rad laboratories Inc., California, United States) and the Premier Hb9210™ (Trinity Biotech Plc., County Wicklow, Ireland)) and another established POC analyser (DCA Vantage® Analyzer (Siemens Healthineers, Erlangen, Germany)) Results: Results showed acceptable precision, with within-run coefficients of variation (CV) of 0.92% and 0.51%, and between-run CVs of 1.07% and 0.66% for control samples. The linearity curve exhibited an R² value of 0.99 across the clinically relevant range. The accuracy was confirmed with a concordance correlation coefficient (CCC) of 0.98 (95% CI: 0.97 to 0.99) and a bias of 0.06, indicating strong agreement with the laboratory reference method. Lot-to-lot variation demonstrated correlation coefficients of 0.98, 0.96, and 0.97 for the three different reagent lots compared to the laboratory method. Clinical data analysis revealed CCCs of 0.93 (95% CI: 0.91 to 0.95) and 0.97 (95% CI: 0.97 to 0.98) when compared to Clinic standard of care (SOC) and the Laboratory SOC, respectively. Conclusion: Collectively, the findings of this study suggest that the LumiraDx HbA1c test is a reliable tool for the measurement of HbA1c, offering a viable alternative to traditional laboratory methods.