title: Biomarker selection for medical diagnosis using the partial area under the ROC curve.
abstract: BACKGROUND
  A biomarker is usually used as a diagnostic or assessment tool in medical research. Finding an ideal biomarker is not easy and combining multiple biomarkers provides a promising alternative. Moreover, some biomarkers based on the optimal linear combination do not have enough discriminatory power. As a result, the aim of this study was to find the significant biomarkers based on the optimal linear combination maximizing the pAUC for assessment of the biomarkers.
  
  
  METHODS
  Under the binormality assumption we obtain the optimal linear combination of biomarkers maximizing the partial area under the receiver operating characteristic curve (pAUC). Related statistical tests are developed for assessment of a biomarker set and of an individual biomarker. Stepwise biomarker selections are introduced to identify those biomarkers of statistical significance.
  
  
  RESULTS
  The results of simulation study and three real examples, Duchenne Muscular Dystrophy disease, heart disease, and breast tissue example are used to show that our methods are most suitable biomarker selection for the data sets of a moderate number of biomarkers.
  
  
  CONCLUSIONS
  Our proposed biomarker selection approaches can be used to find the significant biomarkers based on hypothesis testing.
authors.affiliation: Institute of Statistical Science, Academia Sinica, Taipei 11529, Taiwan. 95354503@nccu.edu.tw.
authors.forename: Man-Jen
authors.initials: MJ
authors.lastname: Hsu
authors.forename: Yuan-Chin Ivan
authors.initials: YC
authors.lastname: Chang
authors.forename: Huey-Miin
authors.initials: HM
authors.lastname: Hsueh
mesh_terms: D000465:Algorithms; D019540:Area Under Curve; D015415:Biomarkers / Q000032:analysis*; D001941:Breast Diseases / Q000473:pathology; D003198:Computer Simulation; D003324:Coronary Artery Disease / Q000097:blood; D003933:Diagnosis; D017097:Electric Impedance; D006580:Genetic Carrier Screening; D020388:Muscular Dystrophy, Duchenne / Q000097:blood / Q000235:genetics; D016011:Normal Distribution; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers