Evaluation of the Accuracy of the LumiraDx INR Test Using Patients in Receipt of Phenprocoumon Anticoagulation Therapy

Background The LumiraDx INR Test is a new point-of-care diagnostic test designed to analyze fingerstick blood samples. The test was assessed in patients receiving phenprocoumon (NCT04074980). Methods Venous plasma international normalized ratio (INR) was measured using the LumiraDx INR Test. LumiraDx INR Test-ascertained capillary whole blood INR was compared with venous plasma INR measured using the IL ACL Elite Pro and Sysmex CS-5100 reference instruments. Results A total of 102 patients receiving phenprocoumon were recruited. The INR results from venous plasma and capillary whole blood that were analyzed on the LumiraDx INR Test correlated well with those measured using the IL ACL Elite Pro (plasma: n = 25, r = 0.981; capillary blood: n = 74, r = 0.949) and the Sysmex CS-5100 (n = 73, r = 0.950). Conclusions The LumiraDx INR Test showed high accuracy in analyzing venous plasma and capillary whole blood from patients receiving phenprocoumon.