Optimized cutoffs improve performance of the aspartate aminotransferase to platelet ratio index for predicting significant liver fibrosis in human immunodeficiency virus/hepatitis C virus co-infection
ABSTRACT To assess the diagnostic value of modified cutoffs for aspartate aminotransferase to platelet ratio index (APRI) to predict significant liver fibrosis in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) patients.
This retrospective cross-sectional study included consecutive patients with HIV/HCV co-infection who underwent percutaneous liver biopsy. The accuracy of APRI for the diagnosis of significant fibrosis (F2/F3/F4 METAVIR) was evaluated by estimating the positive and negative predictive values (PPV and NPV respectively) and by measuring the area under the receiver operating characteristics curve (AUROC).
One hundred and eleven patients were included (73% men, mean age 40.2+/-7.8 years). Significant fibrosis was observed in 45 patients (41%). To discriminate these subjects, the AUROC of APRI was 0.774+/-0.045. An APRI > or = 1.8 showed a PPV of 75% for the presence of significant fibrosis, and an index < 0.6 excluded significant fibrosis with an NPV of 87%. If biopsy indication was based only on APRI and restricted to scores in the intermediate range (> or = 0.6 and < 1.8), 46% of liver biopsies could have been avoided as compared with 40% using the classical cutoffs.
APRI with adjusted cutoffs can predict significant liver fibrosis in patients with HIV/HCV co-infection and might obviate the need to perform a biopsy in a considerable percentage of those subjects.
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ABSTRACT: Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established. To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease. We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists. We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted. Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822. A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments. Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD. This study is registered as PROSPERO CRD42011001561. The National Institute for Health Research Health Technology Assessment programme.Health technology assessment (Winchester, England) 01/2015; 19(9):1-410. DOI:10.3310/hta19090 · 5.12 Impact Factor
Alimentary Pharmacology & Therapeutics 05/2011; 33(10). DOI:10.1111/j.1365-2036.2011.04638.x · 4.55 Impact Factor
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ABSTRACT: Assessment of liver fibrosis in chronic hepatitis C virus (HCV) infection is considered a relevant part of patient care and key for decision making. Although liver biopsy has been considered the gold standard for staging liver fibrosis, it is an invasive technique and subject to sampling errors and significant intra- and inter-observer variability. Over the last decade, several noninvasive markers were proposed for liver fibrosis diagnosis in chronic HCV infection, with variable performance. Besides the clear advantage of being noninvasive, a more objective interpretation of test results may overcome the mentioned intra- and inter-observer variability of liver biopsy. In addition, these tests can theoretically offer a more accurate view of fibrogenic events occurring in the entire liver with the advantage of providing frequent fibrosis evaluation without additional risk. However, in general, these tests show low accuracy in discriminating between intermediate stages of fibrosis and may be influenced by several hepatic and extra-hepatic conditions. These methods are either serum markers (usually combined in a mathematical model) or imaging modalities that can be used separately or combined in algorithms to improve accuracy. In this review we will discuss the different noninvasive methods that are currently available for the evaluation of liver fibrosis in chronic hepatitis C, their advantages, limitations and application in clinical practice.World Journal of Gastroenterology 03/2014; 20(11):2854-2866. DOI:10.3748/wjg.v20.i11.2854 · 2.43 Impact Factor