Background & aims:
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.