Performance of the LumiraDx Platform INR Test in an Anticoagulation Clinic Point-of-Care Setting Compared With an Established Laboratory Reference Method

Robert Campbell Tait, Annielle Hung, Roy S Gardner, Robert Campbell Tait, Annielle Hung, Roy S Gardner

Abstract

Vitamin K antagonists, such as warfarin, have a narrow therapeutic window; patients on these therapies therefore require regular international normalized ratio (INR) monitoring to maintain optimal dosing. This involves periodic checks and laboratory testing using venepuncture, which are often perceived as a burden. This study aimed to determine the accuracy and precision of the LumiraDx INR Test, a new point-of-care in vitro diagnostic platform, in an anticoagulation clinic setting. In this observational, cross-sectional study, 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 laboratory reference instrument, the IL ACL ELITE Pro. Furthermore, INR was assessed across a range of hematocrit (25%-55%). In addition, feedback was collected from health-care professionals via a self-completed questionnaire. This trial was registered at ClinicalTrials.gov (NCT03682419). 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 INR range of 0.8 to 7.5, was confirmed by a strong correlation of 0.965 (95% confidence interval: 0.959-0.970) when compared with the IL ACL ELITE Pro, which was maintained across the hematocrit range. Feedback from health-care professionals indicated that the instructions given by the system were easy to follow. In conclusion, the strong agreement between the LumiraDx Platform INR point-of-care test and the IL ACL ELITE Pro laboratory reference system, as well as between the different application methods and test lots, indicates that it can provide a rapid, accurate, and reliable INR analysis.

Keywords: LumiraDx Platform; international normalized ratio; oral anticoagulation; point-of-care; vitamin K antagonist therapy; warfarin.

Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: This study was sponsored by LumiraDx UK Ltd, Dumyat Business Park, Alloa, United Kingdom.

Figures

Figure 1.
Figure 1.
Scatter plot graph illustrating the correlation of INR measurements between the LumiraDx INR Test and the IL ACL ELITE Pro reference instrument. The INR measurements of directly applied fingerstick capillary whole blood as assessed by the LumiraDx INR Test were correlated with the venous plasma INR assessed by the IL ACL ELITE Pro. Abbreviations: INR, international normalised ratio; Int CI, intersection confidence interval; Slp CI, slope confidence interval.

References

    1. Van Gorp RH, Schurgers LJ. New insights into the pros and cons of the clinical use of vitamin K antagonists (VKAs) versus direct oral anticoagulants (DOACs). Nutrients. 2015;7(11):9538–9557.
    1. Pirmohamed M. Warfarin: the end or the end of one size fits all therapy? J Pers Med. 2018;8(3).
    1. Witt DM, Nieuwlaat R, Clark NP, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy. Blood Adv. 2018;2(22):3257–3291.
    1. Lip GYH, Collet JP, de Caterina R, et al. Antithrombotic therapy in atrial fibrillation associated with valvular heart disease: a joint consensus document from the European Heart Rhythm Association (EHRA) and European Society of Cardiology Working Group on Thrombosis, endorsed by the ESC Working Group on Valvular Heart Disease, Cardiac Arrhythmia Society of Southern Africa (CASSA), Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), South African Heart (SA Heart) Association and Sociedad Latinoamericana de Estimulacion Cardiaca y Electrofisiologia (SOLEACE). Europace. 2017;19(11):1757–1758.
    1. Lung B, Rodes-Cabau J. The optimal management of anti-thrombotic therapy after valve replacement: certainties and uncertainties. Eur Heart J. 2014;35(42):2942–2949.
    1. Shikdar S, Bhattacharya PT. International normalized ratio (INR). StatPearls; . Updated October 27, 2018. Accessed October 2019.
    1. Poller L. International normalized ratios (INR): the first 20 years. J Thromb Haemost 2004;2(6):849–860.
    1. Reiffel AJ. Time to revisit the time in the therapeutic range. J Atr Fibrillation. 2017;9(5):1569.
    1. Christensen TD, Larsen TB. Precision and accuracy of point-of-care testing coagulometers used for self-testing and self-management of oral anticoagulation therapy. J Thromb Haemost. 2012;10(2):251–260.
    1. Al-Momany NH, Makahleh ZM, Al-Omari NA, et al. Analysis of factors that interrupt with INR control in the first anticoagulation clinic monitoring Jordanian patients. Clin Appl Thromb Hemost. 2019;25 doi:10.1177/1076029619870252.
    1. Barcellona D, Fenu L, Marongiu F. Point-of-care testing INR: an overview. Clin Chem Lab Med. 2017;55(6):800–805.
    1. Laurence CO, Gialamas A, Bubner T, et al. Patient satisfaction with point-of-care testing in general practice. Br J Gen Pract. 2010;60(572):e98–e104.
    1. Keeling D, Baglin T, Tait C, et al. Guidelines on oral anticoagulation with warfarin—fourth edition. Br J Haematol. 2011;154(3):311–324.
    1. Kalcik M, Yesin M, Gursoy MO, et al. Comparison of the INR values measured by CoaguChek XS coagulometer and conventional laboratory methods in patients on VKA therapy. Clin Appl Thromb Hemost. 2017;23(2):187–194.
    1. LumiraDx INR Test specifications. 2019. . Accessed February 2019.
    1. Wool GD. Benefits and pitfalls of point-of-care coagulation testing for anticoagulation management: an ACLPS critical review. Am J Clin Pathol. 2019;151(1):1–17.
    1. Scandinavian evaluation of laboratory equipment for point of care testing. . Accessed February 2019.
    1. Lusky K. Are point-of-care PT/INR devices safe and effective? 2017. . Accessed February 2019.
    1. CoaguCheck Pro II. 2019. . Accessed October 2019.

Source: PubMed

Sponsorer og samarbejdspartnere

Medicinske tilstande

Narkotikainterventioner

3
Abonner