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This Article Full Text Full Text (PDF) 085795.Supplemental Data All Versions of this Article: clinchem.2007.085795v1 53/9/1615    most recent Submit an electronic Letter to the Editor about this paper Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Poynard, T. Search for Related Content PubMed PubMed Citation Articles by Poynard, T. Related Collections General Clinical Chemistry Evidence Based Laboratory Medicine and Test Utilization Proteomics and Protein Markers

Standardization of ROC Curve Areas for Diagnostic Evaluation of Liver Fibrosis Markers Based on Prevalences of Fibrosis Stages

¹ Assistance Publique-Hôpitaux de Paris Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
² Laboratoire Alphabio, Marseille, France.
³ Service d’Hépato-gastroentérologie, Hôpital Haut Lévêque, Pessac, France.
⁴ Biopredictive, Paris, France.
⁵ Service d’Hépatogastroentérologie, Hôpital Saint-Joseph, Marseille, France.

^aAddress correspondence to this author at: Assistance Publique-Hôpitaux Groupe Hospitalier Pitié-Salpêtrière, 47-83 Boulevard de l’Hôspital, 75651 Paris Cedex 13, France. Fax 33-142161427; e-mail tpoynard{at}teaser.fr.

Background: The area under the ROC curve (AUC) is widely used as an estimate of the diagnostic value for fibrosis markers. Whether there is variability in the AUC related to the prevalence of fibrosis stages defining advanced and nonadvanced fibrosis is unknown. The aim of this study was to assess the relationships between the AUC and the prevalence of each fibrosis stage and to elaborate simple methods of standardization.

Methods: The AUCs of FibroTest (FT) for the diagnosis of advanced fibrosis were estimated in patients with chronic hepatitis C using an integrated database including 1312 patients with FT and biopsy, and in an overview of 18 diagnostic studies.

Results: In the integrated database considering stage prevalence, the FT AUC for advanced fibrosis varied (P <0.001) from 0.67 (only stage F2 as advanced fibrosis and only F1 as nonadvanced fibrosis) to 0.98 (only F4 as advanced fibrosis and only F0 as nonadvanced fibrosis). The same results were observed in the overview, in which the FT AUC varied (P <0.001) from 0.65 to 0.89 according to fibrosis stage prevalence. Two approaches for expressing standardized AUCs were developed: one approach assumed a uniform prevalence distribution of each fibrosis stage; the other approach used the prevalence distribution of fibrosis stages observed in the population.

Conclusions: The expressions of the AUCs of fibrosis markers should be standardized according to the prevalence of fibrosis stages defining advanced and nonadvanced fibrosis.

The following articles in journals at HighWire Press have cited this article:

				J. Lambert, P. Halfon, G. Penaranda, P. Bedossa, P. Cacoub, and F. Carrat How to Measure the Diagnostic Accuracy of Noninvasive Liver Fibrosis Indices: The Area Under the ROC Curve Revisited Clin. Chem., August 1, 2008; 54(8): 1372 - 1378. [Abstract] [Full Text] [PDF]