title: Performance characteristics of five cardiac Troponin I assays.
abstract: BACKGROUND
  The aim of this study was to evaluate the performance characteristics of cardiac Troponin I (cTnI) assays on the Access 2, Advia Centaur, Architect i1000(SR), Architect i2000(SR), and Vitros ECi analyzers.
  
  
  METHODS
  To determine the 99th percentile, plasma and serum samples were drawn from 400 apparently healthy subjects. Functional sensitivity was evaluated by testing 10 panels of serum pools in duplicate for 10days using 2 reagent lots. Imprecision was also assessed using commercial quality control materials. For method comparison, 100 plasma samples were tested by all methods with the Architect i2000(SR) assay as the comparison method.
  
  
  RESULTS
  The 99th percentile ranged from 0.013 to 0.020microg/l. Calculated CVs at the 99th percentile were 23-52%. cTnI concentrations at a 10% CV ranged from 0.039 to 0.101microg/l. Total CVs determined using quality control materials were 2.4-10.0%. Method comparison results by Deming regression had slopes of 1.03-1.51. The mean bias for cTnI samples between 0.01 and 1.0microg/l ranged from 0 to 0.2microg/l.
  
  
  CONCLUSIONS
  No method demonstrated a concentration with a 10% CV that was less than the 99th percentile for healthy adults. All methods compare well to the Architect i2000(SR) assay with the Advia Centaur having the highest positive bias.
authors.affiliation: ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, United States.
authors.forename: Sonia L
authors.initials: SL
authors.lastname: La'ulu
authors.forename: William L
authors.initials: WL
authors.lastname: Roberts
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry*; D012015:Reference Standards; D012044:Regression Analysis; D015203:Reproducibility of Results; D019210:Troponin I / Q000097:blood*; D055815:Young Adult
chemical_list: D019210:Troponin I