title: Accuracy, reproducibility and clinical utility of the CoaguChek S portable international normalized ratio monitor in an outpatient anticoagulation clinic.
abstract: The accuracy and reproducibility of the CoaguChek S, and its clinical agreement with conventional laboratory international normalized ratio (INR) determination, were evaluated in an outpatient anticoagulation clinic setting. Forty-three patients provided 248 paired INR measurements for analysis. The paired results were highly correlated (r = 0.90). The mean coefficient of variation for the CoaguChek S for a random sample of 21 patients with three repeated tests each, was 4%. Clinical applicability was also measured by discrepant INR values, as defined in the literature by expanded and narrow agreement, and by INR values resulting in a different clinical decision by a blinded haematology registrar. Expanded agreement and narrow agreement between the two INR values occurred 90 and 88% of the time, respectively. The stricter criteria set down by the clinician resulted in 73% of paired results producing the same dosage decision. The CoaguChek S displayed good correlation with laboratory determination of INR and compared relatively well with expanded and narrow clinical agreement criteria.
authors.affiliation: School of Pharmacy, University of Tasmania, Tasmania, Australia.
authors.forename: S L
authors.initials: SL
authors.lastname: Jackson
authors.forename: L R
authors.initials: LR
authors.lastname: Bereznicki
authors.forename: G M
authors.initials: GM
authors.lastname: Peterson
authors.forename: K A
authors.initials: KA
authors.lastname: Marsden
authors.forename: D M L
authors.initials: DM
authors.lastname: Jupe
authors.forename: E
authors.initials: E
authors.lastname: Tegg
authors.forename: J H
authors.initials: JH
authors.lastname: Vial
authors.forename: R I
authors.initials: RI
authors.lastname: Kimber
mesh_terms: D000554:Ambulatory Care Facilities; D000925:Anticoagulants / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000502:physiology; D001778:Blood Coagulation Disorders / Q000097:blood / Q000188:drug therapy; D001780:Blood Coagulation Tests / Q000379:methods* / Q000592:standards; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D019934:International Normalized Ratio / Q000592:standards*; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods* / Q000592:standards; D008991:Monitoring, Physiologic / Q000379:methods / Q000592:standards; D012016:Reference Values; D015203:Reproducibility of Results; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin