Performance of the LumiraDx Platform INR Test in an Anticoagulation ClinicPoint-of-Care Setting Compared With an Established Laboratory ReferenceMethod

摘要

Vitamin K antagonists, such as warfarin, have a narrow therapeutic window; patients onthese therapies therefore require regular international normalized ratio (INR) monitoringto maintain optimal dosing. This involves periodic checks and laboratory testing usingvenepuncture, which are often perceived as a burden. This study aimed to determine theaccuracy and precision of the LumiraDx INR Test, a new point-of-care in vitro diagnosticplatform, in an anticoagulation clinic setting. In this observational, cross-sectionalstudy, precision of the LumiraDx INR Test was assessed using paired replicate samples (n =366) and 3 test strip lots. Accuracy was determined by comparing capillary blood INR,ascertained by the LumiraDx INR Test, with venous plasma INR, measured by the laboratoryreference instrument, the IL ACL ELITE Pro. Furthermore, INR was assessed across a rangeof hematocrit (25%-55%). In addition, feedback was collected from health-careprofessionals via a self-completed questionnaire. This trial was registered at ( ). The precision (% coefficient of variation) of the LumiraDx INR Test was<4 when samples were applied by direct application or via a capillary transfer pipette,as well as between test strip lots. Accuracy of the LumiraDx INR Test, across the INRrange of 0.8 to 7.5, was confirmed by a strong correlation of 0.965 (95% confidenceinterval: 0.959-0.970) when compared with the IL ACL ELITE Pro, which was maintainedacross the hematocrit range. Feedback from health-care professionals indicated that theinstructions given by the system were easy to follow. In conclusion, the strong agreementbetween the LumiraDx Platform INR point-of-care test and the IL ACL ELITE Pro laboratoryreference system, as well as between the different application methods and test lots,indicates that it can provide a rapid, accurate, and reliable INR analysis.