Point-of-care (POC) versus central laboratory instrumentation for monitoring oral anticoagulation

Abstract

Point-of-care (POC) instruments employing fingerstick whole blood to monitor patients treated with warfarin are a popular alternative to complex, central laboratory coagulation analyzers utilizing citrated plasma derived from venipuncture. We investigated the accuracy of two widely utilized POC instruments for oral anticoagulation monitoring compared with a central laboratory instrument. Instrument-to-instrument variation differed for the two POC instruments, which correlated with the central laboratory instrument, but exhibited positive bias of 0.

Comparison of International Normalized Ratios provided by two point-of-care devices and laboratory-based venipuncture in a pharmacist-managed anticoagulation clinic

“…3,[20][21][22] Nevertheless, few clinicians are aware of the implications and ongoing problem of obtaining high INR measurements on POC devices compared with central laboratory instrumentation. Pharmacist-managed anticoagulation clinics rely on accurate determinations of the INR to appropriately adjust warfarin dosing.…”

“…A literature review of similar studies found that a sample of 30-60 patients was common in order to produce statistically significant results. 2,3,11,16 Numerous steps were taken to avoid confounding factors in this study. In order to exclude the potential for lack of experience with obtaining a blood sample from a finger stick and obtaining an erroneous INR result, clinic pharmacists involved in the trial had at least two years of experience performing finger-stick testing.…”

Comparative evaluation of Point Of Care coagulation monitoring by coaguchek XS-comparison with standard laboratory method

“…The earlier meters showed a positive bias at high INR values [8,9]. Sobieraj-Teigue et al [10] evaluated to POC devices, coaguchek and coaguchek XS, and showed that the INR values obtained with coaguchek XS correlated excellently with laboratory results.…”

The Success of Self-Testing for Anticoagulation Therapy

“…So we excluded the patients whose hemotocrite levels were lower than 35% or higher than 55% and took care on group formation in order to have a similar hemotocrite level distribution among the groups. Dorfman et al [5], compared the INR measurements of the POC devices and the laboratory instruments and concluded that the POC measurements of INR were higher than laboratory instruments measurements. The ISI level of the laboratory instrument was 1.29 while the ISI level of POC device was 2.0 and 1.0 and this was the most important limiting factor of this study was [5].…”