New noninvasive assessment of liver fibrosis in chronic hepatitis B: maximal accumulative respiration strain

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND

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.

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease.

DATA SOURCES

We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists.

METHODS

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.

RESULTS

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.

LIMITATIONS

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.

CONCLUSIONS

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.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Real-time elastography for diagnosis of liver fibrosis in chronic hepatitis B

OBJECTIVES

The purpose of this study was to prospectively investigate the value of real-time ultrasound elastography for diagnosis of liver fibrosis in patients with chronic hepatitis B and to correlate the elastographic findings with histologic stages of liver fibrosis and blood parameters.

METHODS

Liver biopsies, blood testing, and real-time elastography were performed in 71 patients with chronic viral hepatitis B and liver cirrhosis. The ratio of the elastic strain of liver tissue to that of muscle tissue was determined and correlated with the histologic fibrosis stages and laboratory examination results.

RESULTS

There was a highly negative correlation between the elastic strain ratio and the histologic fibrosis stage (Spearman r = -0.702; P < .001). There was a high correlation observed between a decreasing elastic strain ratio and an increasing fibrosis stage. With substantial liver fibrosis (Scheuer score ≥ S2) and cirrhosis (S4) as diagnostic criteria, the areas under the receiver operating characteristic curves (AUCs) of the elastic strain ratios were 0.863 and 0.797, respectively. The AUC for substantial fibrosis was higher than the AUC for the blood parameters used to diagnose substantial liver fibrosis. Elastic strain ratio cutoff values of 1.10 and 0.60 were identified as diagnostic of substantial fibrosis and cirrhosis, respectively, with sensitivities of 77.8% and 50.0%, respectively, and specificities of 80.0% and 96.7%.

CONCLUSIONS

Real-time elastography is a new clinically promising and noninvasive method for quantitative assessment of liver fibrosis.