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Performance of a point‐of‐care device in determining prothrombin time in supra‐therapeutic INR s
Author(s) -
Hashimoto V. A. M.,
De Paula E. V.,
Colella M. P.,
Luz Fiusa M. M.,
Montalvao S. A. L.,
Machado T. F. G. S.,
Orsi F. A.,
AnnichinoBizzacchi J. M.
Publication year - 2013
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.12026
Subject(s) - point of care , prothrombin time , prothrombin complex , point (geometry) , chemistry , medicine , pharmacology , mathematics , coagulation , pathology , geometry
Summary Introduction Point‐of‐care ( POC ) devices have been widely adopted for monitoring prothrombin time (PT) ( INR ) following the demonstration of their accuracy compared to standard INR determination. However, guidelines suggest confirmation of POC results when INR s increase above therapeutic range, due to concerns regarding possible inferior performance of POC devices in high INR levels. Unfortunately, patients with supra‐therapeutic INR s are underrepresented in studies that validated these devices. Methods We performed a prospective evaluation of the performance of a POC device in monitoring oral anticoagulation in patients with INR values above 3.5 in a University outpatient anticoagulation clinic. During a 6‐month period, 2322 INR determinations were performed with a POC device, and results above 3.5 were immediately repeated on an automated coagulometer. Results Dual INR determinations by two methods were obtained in 160 visits, with a mean INR from the POC device of 4.52 ± 0.96. Both classical statistics and clinical concordance analysis yielded satisfactory results when the two methods were compared. Conclusion Our results demonstrate that POC devices present good correlation with standard laboratory methods for PT determination in supra‐therapeutic INR s and that differences in clinical management do not support the need for systematic confirmation of these results in nonbleeding patients.