Low interinstrument variability of the international normalized ratio with the coagamate X2/Simplastin excel system

American Journal of Clinical Pathology
M T Cunningham, J D Olson

Abstract

Minimizing the interlaboratory variability of the International Normalized Ratio (INR) for patients receiving coumarin therapy will require local laboratory calibration of individual coagulation instrument/reagent systems. However, some laboratories possess multiple coagulation instruments of the same model, and it is unclear if each instrument would require separate calibration. To address this question, a controlled study was performed that examined the interinstrument variability of the INR on three separate Coagamate X2 coagulometers (Organon Teknika, Durham, NC) using the Simplastin Excel reagent (Organon Teknika) (International Sensitivity Index = 2.14). The interinstrument coefficient of variation (CV) of the INR among the three instruments was 3.4% and 3.5% for patient control plasmas (n = 20) and coumarin plasmas (n = 40, INR range 1.5-4.6), respectively. The number of discordant INRs between paired instruments (one INR within and one INR out of the therapeutic range, plus a difference of at lest 0.4 INR units) was very low (0%). The interinstrument INR CVs for three commercial quality control plasmas were 2.6% (INR = 0.92), 4.1% (INR = 2.1), and 6.3% (INR = 4.5), and correlated well with the low CVs for patient sample...Continue Reading

Citations

Mar 4, 2000·American Journal of Physical Medicine & Rehabilitation·M K SchaufeleD T Burke

❮ Previous
Next ❯

Related Concepts

Related Feeds

Blood Clotting Disorders

Thrombophilia includes conditions with increased tendency for excessive blood clotting. Blood clotting occurs when the body has insufficient amounts of specialized proteins that make blood clot and stop bleeding. Here is the latest research on blood clotting disorders.