title: A multicenter clinical evaluation of the Clot Signature Analyzer.
abstract: BACKGROUND
  The Clot Signature Analyzer (CSA) was designed to assess global hemostasis as a screening assay using non-anticoagulated whole blood. Three different measurements are produced by the instrument: platelet hemostasis time (PHT), clot time (CT), and collagen-induced thrombus formation (CITF).
  
  
  OBJECTIVE
  The purpose of the present study was to determine normal ranges for these measurements and assess the performance of the CSA in patients with well-characterized hemostatic disorders and in normal subjects.
  
  
  METHODS
  Four institutions participated in the study. Each established their own normal reference ranges. Patients with well-characterized hemostatic disorders and concurrent normal controls were subsequently examined.
  
  
  RESULTS
  Normal ranges between institutions were similar although statistically different. One hundred and eight patients were examined: 46 individuals with von Willebrand disease (VWD) (type 1, 26; type 2A, 11; type 2B, six; type 3, three); 38 patients with a coagulation factor deficiency; 13 individuals with platelet function defects; 10 patients taking warfarin; and one individual on low-molecular-weight heparin. Of these patients, 89% had at least one abnormality by CSA: 42/46 VWD patients, 35/38 coagulation protein defect patients, 9/13 patients with platelet function defects, 9/10 patients on warfarin and 1/1 patient on low-molecular-weight heparin. Of 116 normal subjects, 103 (89%) fell within the centers' normal range. These data suggest that the CSA has a good sensitivity for bleeding disorders.
authors.affiliation: Department of Internal Medicine, Georgetown University, Washington, DC, USA. william.fricke@viahealth.org
authors.forename: W
authors.initials: W
authors.lastname: Fricke
authors.forename: P
authors.initials: P
authors.lastname: Kouides
authors.forename: C
authors.initials: C
authors.lastname: Kessler
authors.forename: A H
authors.initials: AH
authors.lastname: Schmaier
authors.forename: Y
authors.initials: Y
authors.lastname: Krijanovski
authors.forename: K
authors.initials: K
authors.lastname: Jagadeesan
authors.forename: J
authors.initials: J
authors.lastname: Joist
mesh_terms: D000328:Adult; D000368:Aged; D001778:Blood Coagulation Disorders / Q000175:diagnosis*; D001780:Blood Coagulation Tests / Q000295:instrumentation*; D001791:Blood Platelet Disorders / Q000175:diagnosis*; D016022:Case-Control Studies; D020147:Coagulation Protein Disorders / Q000175:diagnosis; D005260:Female; D006487:Hemostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010979:Platelet Function Tests / Q000295:instrumentation*; D012016:Reference Values; D012680:Sensitivity and Specificity