Point-of-care (POC) versus central laboratory instrumentation for monitoring oral anticoagulation.
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 0.24 - 0.35 INR units. Positive bias increased as the INR values increased. We conclude that clinicians should exercise caution when interpreting results generated by POC monitors, particularly at high INR values. A high POC measurement of INR does not necessarily warrant decreasing the warfarin dose. Instead, a predefined cut-off range for high INR values generated by POC instruments should mandate confirmatory testing with central laboratory instrumentation.
Dorfman
David M
DM
Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115,USA. ddorfman@partners.org
Goonan
Ellen M
EM
Boutilier
M Kay
MK
Jarolim
Petr
P
Tanasijevica
Milenko
M
Goldhaber
Samuel Z
SZ
D000925:Anticoagulants / Q000097:blood*; D006801:Humans; D019934:International Normalized Ratio / Q000379:methods*; D019095:Point-of-Care Systems; D011786:Quality Control; D015203:Reproducibility of Results; D014859:Warfarin / Q000097:blood*
D000925:Anticoagulants; D014859:Warfarin