title: The precision--recall curve overcame the optimism of the receiver operating characteristic curve in rare diseases.
abstract: OBJECTIVE
  Compare the area under the receiver operating characteristic curve (AUC) vs. the area under the precision-recall curve (AUPRC) in summarizing the performance of a diagnostic biomarker according to the disease prevalence.
  
  
  METHODS
  A simulation study was performed considering different sizes of diseased and nondiseased groups. Values of a biomarker were sampled with various variances and differences in mean values between the two groups. The AUCs and the AUPRCs were examined regarding their agreement and vs. the positive predictive value (PPV) and the negative predictive value (NPV) of the biomarker.
  
  
  RESULTS
  With a disease prevalence of 50%, the AUC and the AUPRC showed high correlations with the PPV and the NPV (ρ > 0.95). With a prevalence of 1%, small PPV and AUPRC values (<0.2) but high AUC values (>0.9) were found. The AUPRC reflected better than the AUC the discriminant ability of the biomarker; it had a higher correlation with the PPV (ρ = 0.995 vs. 0.724; P < 0.001).
  
  
  CONCLUSIONS
  In uncommon and rare diseases, the AUPRC should be preferred to the AUC because it summarizes better the performance of a biomarker.
authors.affiliation: Université de Lyon, Département Biomaths-Santé, Lyon, 92 Rue Pasteur, 69007, France; Université Lyon 1, Département Biomaths-Santé, Villeurbanne, 43 boulevard du 11 Novembre 1918, 69622, France; Hospices Civils de Lyon, Service de Biostatistique Lyon, 165 Chemin du Grand Revoyet, Pierre-Bénite F-69310, France; CNRS UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique-Santé, Villeurbanne F-69100, France.
authors.forename: Brice
authors.initials: B
authors.lastname: Ozenne
authors.affiliation: Université de Lyon, Département Biomaths-Santé, Lyon, 92 Rue Pasteur, 69007, France; Université Lyon 1, Département Biomaths-Santé, Villeurbanne, 43 boulevard du 11 Novembre 1918, 69622, France; Hospices Civils de Lyon, Service de Biostatistique Lyon, 165 Chemin du Grand Revoyet, Pierre-Bénite F-69310, France; CNRS UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique-Santé, Villeurbanne F-69100, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Subtil
authors.affiliation: Université de Lyon, Département Biomaths-Santé, Lyon, 92 Rue Pasteur, 69007, France; Université Lyon 1, Département Biomaths-Santé, Villeurbanne, 43 boulevard du 11 Novembre 1918, 69622, France; Hospices Civils de Lyon, Service de Biostatistique Lyon, 165 Chemin du Grand Revoyet, Pierre-Bénite F-69310, France; CNRS UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique-Santé, Villeurbanne F-69100, France. Electronic address: delphine.maucort-boulch@chu-lyon.fr.
authors.forename: Delphine
authors.initials: D
authors.lastname: Maucort-Boulch
mesh_terms: D019540:Area Under Curve; D015415:Biomarkers; D006801:Humans; D011237:Predictive Value of Tests; D015995:Prevalence; D012372:ROC Curve; D035583:Rare Diseases / Q000453:epidemiology*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers
keywords: Area under the curve; Binary biomarker; Performance assessment; Precision-Recall curve; Rare events; Receiver operating curve