title: Improved Diagnostic Performance of High-Sensitivity Cardiac Troponin Assays Is an Artifact of Censored Data.
abstract: BACKGROUND
  High-sensitivity cardiac troponin assays with improved analytical performance at low concentrations are credited with increased diagnostic sensitivity in acute coronary syndrome patients. We investigated the relationship between analytical sensitivity (detection capability) and diagnostic accuracy and tested the effect of censoring data with a software model.
  
  
  METHODS
  We generated 4 sets of results with decreasing detection capability and compared the ROC curves with and without censored data.
  
  
  RESULTS
  There was no relationship between diagnostic performance and detection capability. When data were censored the diagnostic accuracy decreased progressively with an increase in the threshold concentration for censoring. The ROC curves constructed with censored data have a characteristic appearance with a straight line between the censoring point and the top right hand corner.
  
  
  CONCLUSIONS
  There is not a direct relationship between the diagnostic accuracy and the detection capability of cardiac troponin assays. The artifactual decrease in diagnostic accuracy can be added to the list of reasons why data should not be censored and this practice should be disclosed in studies on diagnostic accuracy.
authors.affiliation: Department of Chemical Pathology, Pathology Queensland, Queensland Health, Brisbane, Australia; carel.pretorius@health.qld.gov.au.|University of Queensland, School of Medicine, Brisbane, Australia.
authors.forename: Carel J
authors.initials: CJ
authors.lastname: Pretorius
authors.affiliation: Department of Chemical Pathology, Pathology Queensland, Queensland Health, Brisbane, Australia.
authors.forename: Jacobus P J
authors.initials: JP
authors.lastname: Ungerer
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis*; D006801:Humans; D012372:ROC Curve; D012984:Software; D014336:Troponin / Q000097:blood*
chemical_list: D014336:Troponin