title: Comparison of international normalized ratio measurement between CoaguChek XS Plus and STA-R coagulation analyzers.
abstract: BACKGROUND
  Point-of-care testing (POCT) coagulometers are increasingly being used in the hospital setting. We investigated whether the prothrombin time international normalized ratio (INR) results by CoaguChek XS Plus (Roche Diagnostics GmbH, Mannheim, Germany) can be used reliably without being confirmed with the INR results by STA-R system (Diagnostica Stago S.A.S, Asnières sur Seine, France).
  
  
  METHODS
  A total of 118 INR measurements by CoaguChek XS Plus and STA-R were compared using Passing/Bablok regression analysis and Bland-Altman plot. Agreement of the INR measurements was further assessed in relation to dosing decision.
  
  
  RESULTS
  The correlation of INR measurements between CoaguChek XS Plus and STA-R was excellent (correlation coefficient = 0.964). The mean difference tended to increase as INR results increased and was 0.25 INR in the therapeutic range (2.0-3.0 INR). The overall agreement was fair to good (kappa = 0.679), and 21/118 (17.8%) INR measurements showed a difference in dosing decision.
  
  
  CONCLUSIONS
  The positive bias of CoaguChek XS Plus may be obvious even in the therapeutic INR range, and dosing decision based on the CoaguChek XS Plus INR results would be different from that based on the STA-R results. The INR measurements by POCT coagulometers still need to be confirmed with the laboratory INR measurements.
authors.affiliation: Department of Laboratory Medicine, School of Medicine and Konkuk University Hospital, Konkuk University, 120-1 Neungdong-ro, Hwayang-dong, Gwangjin-gu, Seoul 143-729, Republic of Korea. dearmina@hanmail.net
authors.forename: Mina
authors.initials: M
authors.lastname: Hur
authors.forename: Hanah
authors.initials: H
authors.lastname: Kim
authors.forename: Chul Min
authors.initials: CM
authors.lastname: Park
authors.forename: Antonio
authors.initials: A
authors.lastname: La Gioia
authors.forename: Sang-Gyu
authors.initials: SG
authors.lastname: Choi
authors.forename: Ju-Hee
authors.initials: JH
authors.lastname: Choi
authors.forename: Hee-Won
authors.initials: HW
authors.lastname: Moon
authors.forename: Yeo-Min
authors.initials: YM
authors.lastname: Yun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects; D001780:Blood Coagulation Tests / Q000295:instrumentation* / Q000592:standards*; D002648:Child; D005260:Female; D006801:Humans; D019934:International Normalized Ratio / Q000379:methods* / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011517:Prothrombin Time / Q000379:methods; D012044:Regression Analysis; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D000925:Anticoagulants