Quality assurance for point-of-care testing of oral anticoagulation: a large-scale evaluation of the Hemochron Junior Signature Microcoagulation System

TY - JOUR

T1 - Quality assurance for point-of-care testing of oral anticoagulation

T2 - a large-scale evaluation of the Hemochron Junior Signature Microcoagulation System

AU - Maddox, J. M.

AU - Bogo, P. H.

AU - McGregor, E.

AU - Pippard, M. J.

AU - Kerr, R.

PY - 2009

Y1 - 2009

N2 - We report the first large-scale evaluation of the Hemochron Junior Signature (HJS) Microcoagulation System for community monitoring of oral anticoagulation and establishment of a programme of internal and external quality assurance. Over 1600 HJS results, with a simultaneous venous sample for central analysis, were obtained over a 19 month period. Monitoring of an initial period of HJS results (n = 135) revealed an International Normalized Ratio (INR) over estimation (mean +1.05), with only 27% of results within 0.5 of the central laboratory INR. A correction factor was introduced which reduced the INR bias to +0.07 and improved the percentage of results within 0.5 of the central laboratory INR to 76% (n = 353). A revised correction factor was later introduced to adjust for an under estimation at higher INR values. This changed the INR bias to -0.05, with 76% of results within 0.5 of the central laboratory INR (n = 1174). Local external quality assurance samples were distributed monthly with a total of 791 samples during the study period. 84% of test results were within 15% of the median value (range 73-97% per month). These results emphasize the value of a robust quality assurance programme when using point-of-care devices for community monitoring of oral anticoagulation.

AB - We report the first large-scale evaluation of the Hemochron Junior Signature (HJS) Microcoagulation System for community monitoring of oral anticoagulation and establishment of a programme of internal and external quality assurance. Over 1600 HJS results, with a simultaneous venous sample for central analysis, were obtained over a 19 month period. Monitoring of an initial period of HJS results (n = 135) revealed an International Normalized Ratio (INR) over estimation (mean +1.05), with only 27% of results within 0.5 of the central laboratory INR. A correction factor was introduced which reduced the INR bias to +0.07 and improved the percentage of results within 0.5 of the central laboratory INR to 76% (n = 353). A revised correction factor was later introduced to adjust for an under estimation at higher INR values. This changed the INR bias to -0.05, with 76% of results within 0.5 of the central laboratory INR (n = 1174). Local external quality assurance samples were distributed monthly with a total of 791 samples during the study period. 84% of test results were within 15% of the median value (range 73-97% per month). These results emphasize the value of a robust quality assurance programme when using point-of-care devices for community monitoring of oral anticoagulation.

KW - Administration, Oral

KW - Anticoagulants

KW - Blood Coagulation Tests

KW - Drug Monitoring

KW - Humans

KW - International Normalized Ratio

KW - Point-of-Care Systems

KW - Quality Control

KW - Warfarin

U2 - 10.1111/j.1751-553X.2007.01013.x

DO - 10.1111/j.1751-553X.2007.01013.x

M3 - Article

C2 - 18177437

VL - 31

SP - 142

EP - 150

JO - International Journal of Laboratory Hematology

JF - International Journal of Laboratory Hematology

IS - 2

ER -