Related Experiment Video
Updated: Jun 21, 2026
Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
Published on: October 12, 2012
Agreement of a new whole-blood PT/INR test using capillary samples with plasma INR determinations
Françoise Boehlen1, Guido Reber, Philippe de Moerloose
1Haemostasis Unit, Department of Medicine, University Hospital, 1211 Geneva 14, Switzerland.
Purpose:
The objective of the study was to compare in anticoagulated patients the international normalized ratio (INR) measured with a new capillary whole-blood device, the i-STAT Portable Clinical Analyser, with conventional plasma INR obtained from the central laboratory.
Patients And Methods:
Between-cartridge variability was first determined with two lyophilized controls with INR levels of 1.60 and 2.75 (n=10). Next, in 35 patients under different intensities of oral anticoagulation, capillary blood INR was measured with two i-STAT devices and was compared to central laboratory plasma INR (Innovin reagent and BCS analyser).
Results:
Between-cartridge coefficients of variation were 5% (95%, CI 3.4-9.1) and 3% (95%, CI 2.1-5.5) at INR levels of 1.60 and 2.75. Mean INR difference between the two i-STAT devices was 0.1, and the correlation coefficient was 0.98. Between i-STAT and central laboratory INR, the correlation coefficient was 0.95. Bias values were 0.04, 0.2, and -0.04 at INR levels of 2.0, 2.5, and 3.5, respectively.
Conclusion:
The INR measured with the i-STAT Portable Clinical Analyser is precise and compares well with plasma INR performed in a central laboratory.
