TY - JOUR
T1 - International normalized ratio monitoring of vitamin K antagonist therapy
T2 - comparative performance of point-of-care and laboratory-derived testing
AU - Bonar, Roslyn
AU - Mohammed, Soma
AU - Favaloro, Emmanuel J
N1 - Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
PY - 2015/4
Y1 - 2015/4
N2 - The monitoring of warfarin therapy using the international normalized ratio (INR) has now moved outside the laboratory's control by use of point-of-care (POC) devices. Although this provides patients with the convenience of immediate results and clinical assessment, POC-INRs are often performed by nonlaboratory staff with little experience in quality control. The Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) Haematology has devised a POC-INR external quality assessment (EQA) program that is suitable for both laboratory and nonlaboratory operators (e.g., nurses) to perform INR testing with good accuracy and precision. A comparison of the performance of the POC versus the laboratory-derived INR testing over the past 8 years has shown that the variation in test results (expressed as coefficient of variation; CV) for laboratory INRs increases with more prolonged INR values, whereas CVs for the POC-INR testing were generally lower, with a reduced dependency on INR values. In our program, the CoaguChek XS (Roche, Basel, Switzerland) showed the best performance among the POC devices. A comparative assessment with other EQA providers showed agreement and disparity with our data in terms of comparative CVs obtained between the laboratory and POC-INRs. The growth of the RCPAQAP POC-INR program from 29 to 360 in the past 12 years highlights the importance of providing suitable EQA for POC-INR staff who are unfamiliar with laboratory practice. This helps maintaining consistent results, which have important implications for the therapeutic management of patients on vitamin K antagonist therapy.
AB - The monitoring of warfarin therapy using the international normalized ratio (INR) has now moved outside the laboratory's control by use of point-of-care (POC) devices. Although this provides patients with the convenience of immediate results and clinical assessment, POC-INRs are often performed by nonlaboratory staff with little experience in quality control. The Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) Haematology has devised a POC-INR external quality assessment (EQA) program that is suitable for both laboratory and nonlaboratory operators (e.g., nurses) to perform INR testing with good accuracy and precision. A comparison of the performance of the POC versus the laboratory-derived INR testing over the past 8 years has shown that the variation in test results (expressed as coefficient of variation; CV) for laboratory INRs increases with more prolonged INR values, whereas CVs for the POC-INR testing were generally lower, with a reduced dependency on INR values. In our program, the CoaguChek XS (Roche, Basel, Switzerland) showed the best performance among the POC devices. A comparative assessment with other EQA providers showed agreement and disparity with our data in terms of comparative CVs obtained between the laboratory and POC-INRs. The growth of the RCPAQAP POC-INR program from 29 to 360 in the past 12 years highlights the importance of providing suitable EQA for POC-INR staff who are unfamiliar with laboratory practice. This helps maintaining consistent results, which have important implications for the therapeutic management of patients on vitamin K antagonist therapy.
KW - Anticoagulants/therapeutic use
KW - Australia
KW - Blood Coagulation/drug effects
KW - Clinical Laboratory Techniques
KW - Drug Monitoring/methods
KW - Hemostasis
KW - Humans
KW - International Cooperation
KW - International Normalized Ratio/standards
KW - New Zealand
KW - Point-of-Care Systems
KW - Point-of-Care Testing
KW - Quality Assurance, Health Care
KW - Quality Control
KW - Reproducibility of Results
KW - Vitamin K/antagonists & inhibitors
KW - Warfarin/administration & dosage
U2 - 10.1055/s-0035-1549091
DO - 10.1055/s-0035-1549091
M3 - Article
C2 - 25839866
SN - 0094-6176
VL - 41
SP - 279
EP - 286
JO - Seminars in Thrombosis and Hemostasis
JF - Seminars in Thrombosis and Hemostasis
IS - 3
ER -