title: Reliability of point-of-care testing of INR in acute stroke.
abstract: BACKGROUND
  In the emergency department, portable point-of-care testing (POCT) coagulation devices may facilitate stroke patient care by providing rapid International Normalized Ratio (INR) measurement. The objective of this study was to evaluate the reliability, validity, and impact on clinical decision-making of a POCT device for INR testing in the setting of acute ischemic stroke (AIS).
  
  
  METHODS
  A total of 150 patients (50 healthy volunteers, 51 anticoagulated patients, 49 AIS patients) were assessed in a tertiary care facility. The INR's were measured using the Roche Coaguchek S and the standard laboratory technique.
  
  
  RESULTS
  The interclass correlation coefficient and 95% confidence interval between overall POCT device and standard laboratory value INRs was high (0.932 (0.69 - 0.78). In the AIS group alone, the correlation coefficient and 95% CI was also high 0.937 (0.59 - 0.74) and diagnostic accuracy of the POCT device was 94%.
  
  
  CONCLUSIONS
  When used by a trained health professional in the emergency department to assess INR in acute ischemic stroke patients, the CoaguChek S is reliable and provides rapid results. However, as concordance with laboratory INR values decreases with higher INR values, it is recommended that with CoaguChek S INRs in the > 1.5 range, a standard laboratory measurement be used to confirm the results.
authors: Calgary Stroke Program, Department of Clinical Neurosciences, University of Calgary, Foothills Hospital, Rm C1101A, 1403-29th Street NW, Calgary, Alberta T2N 2T9, Canada.
authors: Theresa L
authors: TL
authors: Green
authors: Adnan
authors: A
authors: Mansoor
authors: Nancy
authors: N
authors: Newcommon
authors: Caroline
authors: C
authors: Stephenson
authors: Eileen
authors: E
authors: Stewart
authors: Michael D
authors: MD
authors: Hill
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D001777:Blood Coagulation / Q000187:drug effects; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D020521:Stroke / Q000188:drug therapy*; D015912:Thrombolytic Therapy / Q000379:methods*
chemical_list: D005343:Fibrinolytic Agents