title: Comparison of noninvasive markers of fibrosis in patients with nonalcoholic fatty liver disease.
abstract: OBJECTIVE
  There is a need for a reliable and inexpensive noninvasive marker of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We compared the performance of the FIB4 index (based on age, aspartate aminotransferase [AST] and alanine aminotransferase [ALT] levels, and platelet counts) with 6 other non-invasive markers of fibrosis in patients with NAFLD.
  
  
  METHODS
  Using a nation-wide database of 541 adults with NAFLD, jackknife-validated areas under receiver operating characteristic curves (AUROC) of FIB4 and 7 other markers were compared. The sensitivity at 90% specificity, 80% positive predictive value, and 90% negative predictive values were determined along with cutoffs for advanced fibrosis.
  
  
  RESULTS
  The median FIB4 score was 1.11 (interquartile range = 0.74-1.67). The jackknife-validated AUROC for FIB4 was 0.802 (95% confidence interval [CI], 0.758-0.847), which was higher than that of the NAFLD fibrosis score (0.768; 95% CI, 0.720-0.816; P = .09), Goteburg University Cirrhosis Index (0.743; 95% CI, 0.695-0.791; P < .01), AST:ALT ratio (0.742; 95% CI, 0.690-0.794; P < .015), AST:platelet ratio index (0.730; 95% CI, 0.681-0.779; P < .001), AST:platelet ratio (0.720; 95% CI, 0.669-0.770; P < .001), body mass index, AST:ALT, diabetes (BARD) score (0.70; P < .001), or cirrhosis discriminant score (0.666; 95% CI, 0.614-0.718; P < .001). For a fixed specificity of 90% (FIB4 = 1.93), the sensitivity in identifying advanced fibrosis was only 50% (95% CI, 46-55). A FIB4 > or = 2.67 had an 80% positive predictive value and a FIB4 index < or = 1.30 had a 90% negative predictive value.
  
  
  CONCLUSIONS
  The FIB4 index is superior to 7 other noninvasive markers of fibrosis in patients with NAFLD; however its performance characteristics highlight the need for even better noninvasive markers.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA.
authors.forename: Amy G
authors.initials: AG
authors.lastname: Shah
authors.forename: Alison
authors.initials: A
authors.lastname: Lydecker
authors.forename: Karen
authors.initials: K
authors.lastname: Murray
authors.forename: Brent N
authors.initials: BN
authors.lastname: Tetri
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Contos
authors.forename: Arun J
authors.initials: AJ
authors.lastname: Sanyal
mesh_terms: D000328:Adult; D000367:Age Factors; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D015415:Biomarkers; D019937:Diagnostic Techniques and Procedures; D005234:Fatty Liver / Q000150:complications*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011237:Predictive Value of Tests; D012372:ROC Curve
chemical_list: D015415:Biomarkers; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase