Cost Effectiveness of Hepatocellular Carcinoma Surveillance After a Sustained Virologic Response to Therapy in Patients With Hepatitis C Virus Infection and Advanced Fibrosis.

BACKGROUND & AIMS: Hepatitis C virus (HCV)-related cirrhosis increases the risk for hepatocellular carcinoma (HCC). After a sustained virologic response (SVR) to anti-HCV therapy, the risk of HCC is reduced but not eliminated. Recent developments in antiviral therapy have increased rates of SVR markedly. Guidelines recommend indefinite biannual ultrasound surveillance after SVR for patients with advanced fibrosis before treatment. Surveillance for HCC is cost effective before anti-HCV treatment; we investigated whether it remains so after SVR. METHODS: We developed a Markov model to evaluate the cost effectiveness of biannual or annual HCC ultrasound surveillance vs no surveillance in 50-year-old patients with advanced fibrosis after an SVR to anti-HCV therapy. Parameter values were obtained from publications and expert opinions. Primary outcomes were quality-adjusted life-years (QALYs), costs, and the incremental cost-effectiveness ratios (ICERs). RESULTS: With a constant 0.5% annual incidence of HCC, biannual and annual surveillance resulted in ICERs of $106,792 and $72,105 per QALY, respectively, with high false-positive rates. When surveillance was limited to patients with cirrhosis, but not F3 fibrosis, biannual surveillance likely was cost effective, with ICERs of $48,729 and $43,229 per QALY after treatment with interferon and direct-acting antiviral agents, respectively. In patients with F3 fibrosis, the incidence of HCC was 0.3% to 0.4% per year, leading to an ICER of $188,157 per QALY for biannual surveillance. If HCC incidence increases with age, surveillance becomes more cost effective but remains below willingness-to-pay thresholds only for patients with cirrhosis or with pretreatment aspartate aminotransferase to platelet ratio index greater than 2.0 or FIB-4 measurements greater than 3.25. Sensitivity analyses identified HCC incidence and transition rate to symptomatic disease without surveillance as factors that affect cost effectiveness. CONCLUSIONS: In a Markov model, we found HCC surveillance after an SVR to HCV treatment to be cost effective for patients with cirrhosis, but not for patients with F3 fibrosis.

HCV core antigen as an alternative to HCV RNA testing in the era of direct-acting antivirals: retrospective screening and diagnostic cohort studies.

BACKGROUND: Direct-acting antivirals for chronic hepatitis C (HCV) infection have reduced the need for on-treatment HCV RNA monitoring. We assessed the accuracy and cost implications of using HCV core antigen testing to replace HCV RNA testing for confirmation of diagnosis, on-treatment monitoring, and determination of sustained virological response (SVR). METHODS: In a retrospective screening cohort study, de-identified residual serum from unselected samples were obtained from commercial laboratories in Ontario, Canada. Samples from each 5-year age-sex band from birth years 1945-74 collected from Aug 1, 2014, to Feb 28, 2015, were included. All samples that tested positive for HCV antibodies, and 10% of samples that tested negative for HCV antibodies, were tested for HCV core antigen and HCV RNA. A retrospective clinical cohort study was also done using blood samples from patients with confirmed HCV infection collected at four tertiary academic centres: one in Canada, two in Germany, and one in the USA. For assessment of SVR, we included samples from patients who started direct-acting antiviral-based treatment (excluding telaprevir and boceprevir) with or without peginterferon, ribavirin, or both, from Jan 1, 2014, to March 31, 2015. To ensure inclusion of adequate numbers for analysis, patients who relapsed after any treatment regimen were included. Serum samples included in the study were from baseline, week 4 on-treatment (only for patients treated with direct-acting antivirals), end of treatment, and week 12 or 24 of follow-up. The sensitivity and specificity of core antigen testing as a diagnostic tool was assessed in the screening cohort, using HCV RNA as a reference. The sensitivity and specificity of core antigen testing as well as its concordance with HCV RNA testing in the clinical cohort was assessed at baseline, week 4 on-treatment, and at weeks 12 or 24 after the end of treatment in patients undergoing therapy with direct-acting antivirals. The cost-effectiveness of core antigen testing with and without confirmatory HCV RNA testing for negative samples was also assessed. FINDINGS: From 10 006 samples in the screening cohort, 75 of 80 viraemic (HCV RNA-positive) samples tested positive for HCV core antigen (sensitivity 94%, 95% CI 86-98), and none of the 993 HCV RNA-negative samples tested positive for HCV core antigen (specificity 100%, 95% CI 94-100). The five viraemic samples that tested negative for HCV core antigen had low corresponding HCV RNA concentrations. In the clinical cohort, two (1%) of 202 baseline samples tested negative for HCV core antigen; one had a low HCV RNA concentration (468 IU/mL), the other had a high HCV RNA concentration (>2 000 000 IU/mL). By week 4 of treatment, HCV core antigen concentrations decreased in all patients but were not predictive of SVR. Although there was good concordance between HCV RNA and HCV core antigen results at 12 weeks after the end of treatment (r=0·97; p<0·0001), three of the 148 patients who achieved SVR at 12 weeks tested HCV core antigen positive. 12 weeks after the end of treatment, HCV core antigen was undetectable in one (1%) of 71 samples from patients who were identified as having relapsed according to HCV RNA detection. On-treatment and end-of-treatment testing of core antigen or HCV RNA provided little clinical value. The use of HCV core antigen testing as a confirmatory diagnostic strategy was cost saving relative to HCV RNA testing, with a reduction of CAD$0·29-3·70 per patient screened depending on whether HCV RNA testing was used to confirm HCV core antigen-negative results. INTERPRETATION: These data support the use of HCV core antigen testing to document HCV viraemia in a cost-saving diagnostic algorithm. In a treatment setting, HCV core antigen testing can be used instead of HCV RNA testing for diagnosis and documentation of treatment adherence, but it might not be adequate to determine SVR. This approach might improve access to care, particularly in low-income and middle-income countries. FUNDING: Abbott Diagnostics and Toronto Centre for Liver Disease.

Determining optimal sample sizes for multi-stage randomized clinical trials using value of information methods.

BACKGROUND: Traditional sample size calculations for randomized clinical trials depend on somewhat arbitrarily chosen factors, such as Type I and II errors. An effectiveness trial (otherwise known as a pragmatic trial or management trial) is essentially an effort to inform decision-making, i.e., should treatment be adopted over standard? Taking a societal perspective and using Bayesian decision theory, Willan and Pinto (Stat. Med. 2005; 24:1791-1806 and Stat. Med. 2006; 25:720) show how to determine the sample size that maximizes the expected net gain, i.e., the difference between the cost of doing the trial and the value of the information gained from the results. METHODS: These methods are extended to include multi-stage adaptive designs, with a solution given for a two-stage design. The methods are applied to two examples. RESULTS: As demonstrated by the two examples, substantial increases in the expected net gain (ENG) can be realized by using multi-stage adaptive designs based on expected value of information methods. In addition, the expected sample size and total cost may be reduced. LIMITATIONS: Exact solutions have been provided for the two-stage design. Solutions for higher-order designs may prove to be prohibitively complex and approximate solutions may be required. CONCLUSIONS: The use of multi-stage adaptive designs for randomized clinical trials based on expected value of sample information methods leads to substantial gains in the ENG and reductions in the expected sample size and total cost.

Cost-effectiveness analysis of a multinational RCT with a binary measure of effectiveness and an interacting covariate.

In a recent multinational randomized clinical trial, 1356 patients from 14 countries were randomized between two arms. The primary measure of effectiveness was 30-day survival. Health care utilization was collected on all patients and was combined with a single country's price weights to provide patient-level cost data. The purpose of this paper is to report the results of the cost-effectiveness analysis for the country that provided the cost weights, so as to provide a case study for illustrating recently proposed methodologies that account for skewed cost data, the between-country variation in treatment effects, possible interactions between treatment and baseline covariates, and the difficulty of estimated adjusted risk differences. A hierarchal model is used to account for the two sources of variation (between country and between patients, within a country). The model, which uses gamma distributions for cost data and recent methods for estimating adjusted risk differences, provides overall and country-specific estimates of treatment effects. Model estimation is facilitated by Markov chain Monte Carlo methods using the WinBUGS software. In addition, the theory of expected value of information is used to determine if the data provided by the trial are sufficient for decision making.