Validation of FIB-4 and comparison with other simple noninvasive indices for predicting liver fibrosis and cirrhosis in hepatitis B virus-infected patients

Backgrounds To optimize management and predict long-term clinical courses in patients with chronic hepatitis B (CHB), noninvasive tests to determine the degree of hepatic fibrosis have been developed. Aims This study aimed to validate a simple, noninvasive FIB-4 index, which was first derived from an HCV-HIV-co-infected population, in patients with CHB and to compare it with other noninvasive tests for predicting cirrhosis. Methods From 2006-2008, a total of 668 consecutive CHB patients who underwent liver biopsies were enrolled. The fibrosis stage was assessed according to the Batts and Ludwig system by a single pathologist blinded to patients' data. Results For prediction of significant (F >= 2) and severe (F >= 3) fibrosis, and cirrhosis (F=4), the area under the receiver-operating characteristic curves were 0.865, 0.910 and 0.926 respectively. In predicting cirrhosis, it demonstrated diagnostic values comparable to the age-spleen platelet ratio index (0.937, P=0.414) and age-platelet index (0.928, P=0.888), and better outcomes than spleen-platelet ratio index (0.882, P=0.007), aspartate aminotransferase (AST)-platelet ratio index (0.731, P < 0.001) and AST-alanine aminotransferase ratio index (0.730, P < 0.001). FIB-4 cut-offs of 1.6 and 3.6 provided 93.2% negative predictive value and 90.8% positive predictive value for detection of cirrhosis respectively. Based on these results, liver biopsy could be avoided in 70.5% of the study population. These cut-offs were validated internally using bootstrap resampling methods, showing good agreement. Conclusions FIB-4 is a simple, accurate and inexpensive method of predicting cirrhosis, with outcomes comparable to other noninvasive tests and may reduce the need for liver biopsy in the majority of CHB patients.