Thromb Haemost 2020; 120(04): 687-691
DOI: 10.1055/s-0040-1708034
New Technologies, Diagnostic Tools and Drugs
Georg Thieme Verlag KG Stuttgart · New York

Performance of the microINR Point-of-Care System: A Multicenter Clinical Trial

Majed A. Refaai
1   Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States
Vinay Shah
2   Department of Medicine, Henry Ford Hospital K-15, Detroit, Michigan, United States
Ronald Fernando
3   Department of Internal Medicine, VA Loma Linda Healthcare System, Loma Linda, California, United States
› Author Affiliations
Funding This study was funded by iLine Microsystems S.L.
Further Information

Publication History

19 August 2019

29 January 2020

Publication Date:
16 April 2020 (online)


Introduction There are limited publications about the microINR point-of-care (POC) system (iLine Microsystems). The current microINR POC system was compared with the ACL TOP 500 laboratory analyzer (Instrumentation Laboratory) and with the CoaguChek XS POC system (Roche Diagnostics).

Methods This study was performed at three United States medical centers. Sixty-eight nonanticoagulated normal donors and 245 warfarin anticoagulated patients were included. Testing was performed in duplicate using capillary blood samples for the POC systems and venous blood samples for the laboratory testing. Accuracy and imprecision were assessed.

Results Comparing microINR to ACL revealed a correlation coefficient (r) of 0.973, a slope of 1.00 (95% confidence interval [CI], 0.97–1.03), and an intercept of 0.08 (95% CI, 0.04–0.15). When compared with the CoaguChek XS, r was 0.977 with a slope of 0.92 (95% CI, 0.89–0.94) and an intercept of 0.15 (95% CI, 0.08–0.19). Predicted bias values at international normalized ratio (INR) 2.0, 3.5, and 4.5 were ≤ 5% against both references. Agreement with ACL was 97, 95, and 100% for the INR ranges of < 2.0 ± 0.40, 2.0 to 4.5 ± 20%, and ≥ 4.5 ± 25%, respectively. Agreement for the combined INR ranges was 96% against ACL and > 96% against the CoaguChek XS. The coefficient of variation of the microINR was 5.03% for INR < 2.0 and 4.68% for the therapeutic INR range 2.0 to 3.5.

Conclusion The microINR results demonstrate adequate imprecision and accuracy to both ACL and CoaguChek XS. This indicates that monitoring INR by this microINR POC system is reliable and acceptable for the management of warfarin therapy.


All authors serve as principle investigators of this clinical trial.

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