A comparison of point-of-gate instruments designed for monitoring oral anticoagulation with standard laboratory methods

Our study compared point-of-care (POC) device monitoring with traditional c linical laboratory methods device of patients on oral anticoagulant therapy . The POC devices used in the study were Coumatrak, CoaguChek, CoaguChek Pl us, Thrombolytic Assessment System (TAS) PT-One, TAS PTNC, TAS PT, Hemachro n Jr. Signature, Pro-time Microcoagulation System, and Medtronics ACT II. T he clinical laboratory method used thromboplastins with different ISI value s: Innovin and Thromboplastin C Plus (TPC). All POC INRs showed strong corr elation with both laboratory methods, with correlation coefficients of >0.9 00. All POC methods demonstrated a significant (p <0.05) difference in INR values, except the TAS PTNC and ACT II INRs (p: 0.12 and 0.71 respectively) when compared with Innovin INRs. All POC INRs were significantly different from TPC generated INRs (p <0.05). Comparisons of the POC INRs to the grou p mean of the POC methods, show higher correlation (R>0.93), but there were still significant (p<0.05) differences noted between the POC group INR mea n and CoaguChek Plus, ACT II, TAS PT-One, TAS PTNC, and Hemachron Jr Signat ure INRs. These data indicate that POC INR biases exist between laboratory methods and POC devices. Until a suitable whole blood INR standardization m ethod is available, we conclude that clinicians using point-of-care anticoa gulation monitoring should be aware of differences between POC and parent l aboratory values.