The aspartate aminotransferase-to-platelet ratio index (APRI), a tool with limited expense and widespread availability, is a promising noninvasive alternative to liver biopsy for detecting hepatic fibrosis. The objective of this study was to update the 2007 meta-analysis to systematically assess the accuracy of APRI in predicting significant fibrosis, severe fibrosis, and cirrhosis stage in hepatitis C virus (HCV) monoinfected and HCV / human immunodeficiency virus (HIV) coinfected individuals. Studies comparing APRI versus biopsy in HCV patients were identified via a thorough literature search. Areas under summary receiver operating characteristic curves (AUROC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were used to examine the APRI accuracy for the diagnosis of significant fibrosis, severe fibrosis, and cirrhosis. Heterogeneity was explored using meta-regression. Twenty-one additional studies were eligible for the update and, in total, 40 studies were included in this review (n 5 8,739). The summary AUROC of the APRI for the diagnosis of significant fibrosis, severe fibrosis, and cirrhosis were 0.77, 0.80, and 0.83, respectively. For significant fibrosis, an APRI threshold of 0.7 was 77% sensitive and 72% specific. For severe fibrosis, a threshold of 1.0 was 61% sensitive and 64% specific. For cirrhosis, a threshold of 1.0 was 76% sensitive and 72% specific. Moreover, we found that the APRI was less accurate for the identification of significant fibrosis, severe fibrosis, and cirrhosis in HIV/HCV coinfected patients. Conclusion: Our large meta-analysis suggests that APRI can identify hepatitis C-related fibrosis with a moderate degree of accuracy. Application of this index may decrease the need for staging liver biopsy specimens among chronic hepatitis C patients. (HEPATOLOGY 2011;53:726-736) H epatitis C virus (HCV) infection, with an estimated prevalence of more than 170 million worldwide, is a major public healthcare problem. 1 Chronic hepatitis C (CHC) is the most common cause of cirrhosis and hepatocellular carcinoma (HCC), and the leading indication for liver transplantation in the United States and many Western countries. Cirrhosis and its disease-related complications are responsible for more than 40,000 deaths annually in the United States. 2 HCV chronic infection develops into chronic hepatitis in more than 70% of patients and in about 20% of them progresses to cirrhosis and eventually HCC. 3 In HCV monoinfected patients with compensated cirrhosis, the cumulative incidences of HCC, ascites, bleeding, and encephalopathy at 5 and 10 years were 7.8%/7%/2.5%/0% and 28%/20%/5%/2.5%, respectively. 4 Early diagnosis of cirrhosis is important in patients with CHC not only because it prompts screening for HCC and esophageal Abbreviations: APRI, aspartate aminotransferase-to-platelet ratio index; AUROC, area under the receiver operating characteristic curve; DOR, diagnostic odds ratio; HCV, hepatitis C virus; NPV, negative predictive value; PPV, positive predictive value; QUADAS, the Quality Assessment of Studies of Diagnostic Accuracy Included in Systematic Reviews; SROC, summary receiver operating characteristic curves.