title: Precision of INR measured with a patient operated whole blood coagulometer.
abstract: BACKGROUND
  The objective of the present study was to evaluate the precision of a portable whole blood coagulometer (CoaguChek S) in the hands of self-managing patients on oral anticoagulant therapy (OAT).
  
  
  METHODS
  Fifteen patients on self-managed OAT performed measurements of INR by two types of portable whole blood coagulometers (CoaguChek and CoaguChek S) at home for 10 weeks.
  
  
  RESULTS
  The coefficient of variation (CV) of INRs determined at home by CoaguChek S by patients on self-managed OAT was 5.5% (95% confidence limits: 4.9%, 6.1%). The biological CV of INR within and between patients was 15.0% and 14.7%, respectively.
  
  
  CONCLUSIONS
  The precision of CoaguChek S is satisfactory.
authors.affiliation: Department of Biostatistics, University of Aarhus, Vennelyst Boulevard 6, DK-8000 Aarhus C, Denmark. jorn.attermann@bisam.dk
authors.forename: Jørn
authors.initials: J
authors.lastname: Attermann
authors.forename: Niels T
authors.initials: NT
authors.lastname: Andersen
authors.forename: Helle
authors.initials: H
authors.lastname: Korsgaard
authors.forename: Marianne
authors.initials: M
authors.lastname: Maegaard
authors.forename: J Michael
authors.initials: JM
authors.lastname: Hasenkam
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D019934:International Normalized Ratio / Q000295:instrumentation*; D008297:Male; D015203:Reproducibility of Results; D012648:Self Care / Q000295:instrumentation*