Multicenter evaluation of a new capillary blood prothrombin time monitoring system.

The analytical performance of the new capillary blood prothrombin time monitoring system CoaguChek was examined in a multicenter evaluation at six hospitals. The coefficients of variation of the INR obtained in the CoaguChek imprecision study were approximately 7% in the control plasma provided (within-run and day-to-day) and 4% in blood (within-run). The prothrombin times were ascertained in capillary blood (CoaguChek PT Test) and citrated venous plasma (Hepato Quick, Thromborel S) from 359 patients under oral anticoagulation therapy with phenprocoumon, acenocoumarin or warfarin. The agreement with the test results obtained with the comparison methods was acceptable versus Hepato Quick assay (n = 359; y = 1.23 x -0.49, r = 0.888) and good versus Thromborel S method (n = 359; y = 1.09 x -0.28, r = 0.895). A simplified assessment of all test results (n = 795) in a nine-field comparison table showed a concordance with the comparison methods of more than 80 (Hepato Quick: 81%, Thromborel S: 83%). The concordance between Hepato-Quick and Thromborel S was slightly higher (88%). Its good analytical performance and convenient handling recommend the CoaguChek system as a suitable system for decentralized prothrombin time testing.