The burden of hepatitis C in England

Analysing HCV incidence trends in people who inject drugs using serial behavioural and seroprevalence data: A modelling study

INTRODUCTION

The introduction of new direct-acting antivirals for hepatitis C virus (HCV) infection, has enabled the formulation of a HCV elimination strategy led by the World Health Organisation (WHO). Guidelines for elimination of HCV target a reduction in incidence, but this is difficult to measure and needs estimating.

METHODS

Serial cross-sectional bio-behavioural sero-surveys provide information on an individual's infection status and duration of exposure and how these change over time. These data can be used to estimate the rate of first infection through appropriate statistical models. This study utilised updated HCV seroprevalence information from the Unlinked Anonymous Monitoring survey, an annual survey of England, Wales and Northern Ireland monitoring the prevalence of blood borne viruses in people who inject drugs. Flexible parametric and semiparametric approaches, including fractional polynomials and splines, for estimating incidence rates by exposure time and survey year were implemented and compared.

RESULTS

Incidence rates were shown to peak in those recently initiating injecting drug use at approximately 0.20 infections per person-year followed by a rapid reduction in the subsequent few years of injecting to approximately 0.05 infections per person-year. There was evidence of a rise in incidence rates for recent initiates between 2011 and 2020 from 0.17 infections per person-year (95 % CI, 0.16-0.19) to 0.26 infections per person-year (0.23-0.30). In those injecting for longer durations, incidence rates were stable over time.

CONCLUSIONS

Fractional polynomials provided an adequate fit with relatively few parameters, but splines may be preferable to ensure flexibility, in particular, to detect short-term changes in the rate of first infection over time that may be a result of treatment effects. Although chronic HCV prevalence has declined with treatment scale up over 2016-2020, there is no evidence yet of a corresponding fall in the rate of first infection. Seroprevalence and risk behaviour data can be used to estimate and monitor HCV incidence, providing insight into progress towards WHO defined elimination of HCV.

Machine Learning Model Validated to Predict Outcomes of Liver Transplantation Recipients with Hepatitis C: The Romanian National Transplant Agency Cohort Experience

BACKGROUND AND OBJECTIVES

In the early period after liver transplantation, patients are exposed to a high rate of complications and several scores are currently available to predict adverse postoperative outcomes. However, an ideal, universally accepted and validated score to predict adverse events in liver transplant recipients with hepatitis C is lacking. Therefore, we aimed to establish and validate a machine learning (ML) model to predict short-term outcomes of hepatitis C patients who underwent liver transplantation.

MATERIALS AND METHODS

We conducted a retrospective observational two-center cohort study involving hepatitis C patients who underwent liver transplantation. Based on clinical and laboratory parameters, the dataset was used to train a deep-learning model for predicting short-term postoperative complications (within one month following liver transplantation). Adverse events prediction in the postoperative setting was the primary study outcome.

RESULTS

A total of 90 liver transplant recipients with hepatitis C were enrolled in the present study, 80 patients in the training cohort and ten in the validation cohort, respectively. The age range of the participants was 12-68 years, 51 (56,7%) were male, and 39 (43.3%) were female. Throughout the 85 training epochs, the model achieved a very good performance, with the accuracy ranging between 99.76% and 100%. After testing the model on the validation set, the deep-learning classifier confirmed the performance in predicting postoperative complications, achieving an accuracy of 100% on unseen data.

CONCLUSIONS

We successfully developed a ML model to predict postoperative complications following liver transplantation in hepatitis C patients. The model demonstrated an excellent performance for accurate adverse event prediction. Consequently, the present study constitutes the foundation for careful and non-invasive identification of high-risk patients who might benefit from a more intensive postoperative monitoring strategy.

Estimation of COVID-19 Period Prevalence and the Undiagnosed Population in Canadian Provinces: Model-Based Analysis

BACKGROUND

The development of a successful COVID-19 control strategy requires a thorough understanding of the trends in geographic and demographic distributions of disease burden. In terms of the estimation of the population prevalence, this includes the crucial process of unravelling the number of patients who remain undiagnosed.

OBJECTIVE

This study estimates the period prevalence of COVID-19 between March 1, 2020, and November 30, 2020, and the proportion of the infected population that remained undiagnosed in the Canadian provinces of Quebec, Ontario, Alberta, and British Columbia.

METHODS

A model-based mathematical framework based on a disease progression and transmission model was developed to estimate the historical prevalence of COVID-19 using provincial-level statistics reporting seroprevalence, diagnoses, and deaths resulting from COVID-19. The framework was applied to three different age cohorts (< 30; 30-69; and ≥70 years) in each of the provinces studied.

RESULTS

The estimates of COVID-19 period prevalence between March 1, 2020, and November 30, 2020, were 4.73% (95% CI 4.42%-4.99%) for Quebec, 2.88% (95% CI 2.75%-3.02%) for Ontario, 3.27% (95% CI 2.72%-3.70%) for Alberta, and 2.95% (95% CI 2.77%-3.15%) for British Columbia. Among the cohorts considered in this study, the estimated total number of infections ranged from 2-fold the number of diagnoses (among Quebecers, aged ≥70 years: 26,476/53,549, 49.44%) to 6-fold the number of diagnoses (among British Columbians aged ≥70 years: 3108/18,147, 17.12%).

CONCLUSIONS

Our estimates indicate that a high proportion of the population infected between March 1 and November 30, 2020, remained undiagnosed. Knowledge of COVID-19 period prevalence and the undiagnosed population can provide vital evidence that policy makers can consider when planning COVID-19 control interventions and vaccination programs.

Estimating chronic hepatitis C prevalence in British Columbia and Ontario, Canada, using population-based cohort studies

Patients identified as having chronic hepatitis C (CHC) infection can be effectively and rapidly treated using direct-acting antiviral agents. However, there remains a substantial burden of subclinical undetected infection. This study estimates the prevalence and undiagnosed proportion of CHC in British Columbia (BC) and Ontario, Canada, using a model-based approach, informed by provincial population-level health administrative data. A two-step approach was used: Step 1) Two population-based retrospective analyses of administrative health data for a cohort of British Columbians and a cohort of Ontarians with CHC were conducted to generate population-level statistics of CHC-related health events; Step 2) using a validated natural history model of hepatitis C virus (HCV) infection, the historical prevalence of CHC was back-calculated from the data collected in Step 1. Our retrospective study found that, in BC and Ontario, the number of newly diagnosed CHC cases is declining yearly while the complications of the disease are increasing yearly. BC had a 2014 CHC prevalence of 1.04% (95% CI: 0.84%-1.44%), with 33.3% (95% CI: 25.5%-42.0%) of CHC cases undiagnosed. Ontario had a 2014 CHC prevalence of 0.91% (95% CI: 0.83%-1.02%) with 36.0% (95% CI: 31.2%-38.9%) of CHC cases undiagnosed. Our study offers robust estimates based on the integration of a validated natural history model with population-level health administrative data on HCV-related events, which can provide vital evidence for policymakers to develop appropriate policies to achieve elimination targets. Our approach can also be applied to produce robust region-specific estimates in other countries.

Hospital discharges of hepatocellular carcinoma and non-alcohol related cirrhosis in the EU/EEA and United Kingdom: a descriptive analysis of 2004-2015 data

BACKGROUND

Viral hepatitis is a leading cause of mortality globally, comparable to that of HIV and TB. Most hepatitis deaths are related to liver cirrhosis and hepatocellular carcinoma (HCC) associated with chronic hepatitis B and C infections. To examine the progress towards the elimination goals set in the global health sector strategy for viral hepatitis, we aimed to assess the impact of mortality-indicative morbidity.

METHODS

We retrieved inpatients and day cases hospital discharges data from the Eurostat hospital activities database, and analysed ICD-10 and ICD-9 specific codes related to primary HCC and non-alcohol related cirrhosis registered by European Union/European Economic Area (EU/EEA) countries and United Kingdom (UK) for 2004 to 2015.

RESULTS

In 2015, 20 countries (45.7% of total EU/EEA/UK population) reported 13,236 (Range 0-6294) day cases and 36,012 (4-9097) inpatients discharges of HCC. Romania, Croatia, Luxembourg and UK reported increasing day cases discharge rates between 2004 and 2015; while HCC inpatients discharge rates increased overall during this period. There were 13,865 (0-5918) day cases and 56,176 (3-29,118) inpatients discharges reported for cirrhosis across the 20 countries in 2015. Over the 12 years, day cases discharge rates for cirrhosis increased in Romania, Croatia and UK. Though higher than for day cases, cirrhosis inpatients discharge rates remained stable.

CONCLUSIONS

The hospital burden of HCC and cirrhosis is high, with considerable inpatient load including sustained increasing trends in HCC discharge rates. Further interpretation in light of local health system contexts, and more robust harmonised data are needed to better understand the impact of the viral hepatitis epidemic in the region.

Estimation of fibrosis progression rates for chronic hepatitis C: a systematic review and meta-analysis update

OBJECTIVES

Mathematical models are increasingly important in planning for the upcoming chronic hepatitis C (CHC) elimination efforts. Such models require reliable natural history inputs to make accurate predictions on health and economic outcomes. Yet, hepatitis C virus disease progression is known to vary widely in the literature and published inputs are currently outdated. The objectives of this study were to obtain updated estimates of fibrosis progression rates (FPR) in treatment-naïve patients with CHC and to explore sources of heterogeneity.

DESIGN

A systematic review was conducted using Ovid-MEDLINE, Ovid-EMBASE and PubMed databases (January 1990 to January 2018) to identify observational studies of hepatic fibrosis in treatment-naïve patients with CHC.

OUTCOMES

Stage-constant FPRs were estimated for each study given the reported fibrosis scores and duration of infection. Stage-specific FPRs (ie, F0→F1; F1→F2; F2→F3; F3→F4) were estimated using Markov maximum likelihood estimation. Estimates were pooled using random-effects meta-analysis and heterogeneity was evaluated by stratification and random-effects meta-regression.

RESULTS

The review identified 111 studies involving 131 groups of patients (n=42 693). The pooled stage-constant FPR was 0.094 (95% CI 0.088 to 0.100); stage-specific FPRs were F0→F1: 0.107 (95% CI 0.097 to 0.118); F1→F2: 0.082 (95% CI 0.074 to 0.091); F2→F3: 0.117 (95% CI 0.107 to 0.129); F3→F4: 0.116 (95% CI 0.104 to 0.131). Stratified analysis revealed substantial variation in progression by study population. Meta-regression indicated associations between progression and infection age, duration, source, viral genotype and study population. Findings indicate that FPRs display substantial heterogeneity across study populations and pooled values from more homogenous subpopulations should be considered when estimating prognosis.

CONCLUSIONS

This large meta-analysis presents updated prognostic estimates for CHC derived from newer studies using better diagnostic methods and improves estimates for important patient populations in terms of clinical policy (eg, injection drug users, non-clinical populations, liver clinic patients) and should be a valuable resource for patients, clinicians and clinical policymakers.

Cost-Effectiveness of One-Time Birth Cohort Screening for Hepatitis C as Part of the National Health Service Health Check Program in England

BACKGROUND AND OBJECTIVES

Birth cohort screening for the hepatitis C virus (HCV) has been implemented in the US, but there is little evidence of its cost-effectiveness in England. We aim to evaluate the cost-effectiveness of one-time HCV screening for individuals born between 1950 and 1979 as part of the National Health Service health check in England, a health check for adults aged 40 to 74 years in primary care.

METHODS

A Markov model was developed to analyze add-on HCV testing to the National Health Service health check for individuals in birth cohorts between 1950 and 1979, versus current background HCV testing only, over a lifetime horizon. The model used data from a back-calculation model of the burden of HCV in England, sentinel surveillance of HCV testing, and published literature. Results are presented from a health service perspective in pounds in 2017, as incremental cost-effectiveness ratios per quality-adjusted life years gained.

RESULTS

The base-case incremental cost-effectiveness ratios ranged from £7648 to £24 434, and £18 681 to £46 024, across birth cohorts when considering 2 sources of HCV transition probabilities. The intervention is most likely to be cost-effective for those born in the 1970s, and potentially cost-effective for those born from 1955 to 1969. The model results were most sensitive to the source of HCV transition probabilities, the probability of referral and receiving treatment, and the HCV prevalence among testers. The maximum value of future research across all birth cohorts was £11.3 million at £20 000 per quality-adjusted life years gained.

CONCLUSION

Birth cohort screening is likely to be cost-effective for younger birth cohorts, although considerable uncertainty exists for other birth cohorts. Further studies are warranted to reduce uncertainty in cost-effectiveness and consider the acceptability of the intervention.

Extending Bayesian back-calculation to estimate age and time specific HIV incidence

CD4-based multi-state back-calculation methods are key for monitoring the HIV epidemic, providing estimates of HIV incidence and diagnosis rates by disentangling their inter-related contribution to the observed surveillance data. This paper, extends existing approaches to age-specific settings, permitting the joint estimation of age- and time-specific incidence and diagnosis rates and the derivation of other epidemiological quantities of interest. This allows the identification of specific age-groups at higher risk of infection, which is crucial in directing public health interventions. We investigate, through simulation studies, the suitability of various bivariate splines for the non-parametric modelling of the latent age- and time-specific incidence and illustrate our method on routinely collected data from the HIV epidemic among gay and bisexual men in England and Wales.

Monitoring the hepatitis C epidemic in England and evaluating intervention scale-up using routinely collected data

In England, 160 000 individuals were estimated to be chronically infected with hepatitis C virus (HCV) in 2005 and the burden of severe HCV-related liver disease has increased steadily for the past 15 years. Direct-acting antiviral treatments can clear infection in most patients, motivating HCV elimination targets. However, the current burden of HCV is unknown and new methods are required to monitor progress. We employed a Bayesian back-calculation approach, combining data on severe HCV-related liver disease and disease progression, to reconstruct historical HCV incidence and estimate current prevalence in England. We explicitly modelled infections occurring in people who inject drugs, the key risk group, allowing information on the size of this population and surveillance data on HCV prevalence to inform recent incidence. We estimated that there were 143 000 chronic infections in 2015 (95% credible interval 123 000-161 000), with 34% and 54% in those with recent and past injecting drug use, respectively. Following the planned scale-up of new treatments, chronic infections were predicted to fall to 113 400 (94 900-132 400) by the end of 2018 and to 89 500 (71 300-108 600) by the end of 2020. Numbers developing severe HCV-related liver disease were predicted to fall by at least 24% from 2015 to 2020. Thus, we describe a coherent framework to monitor progress using routinely collected data, which can be extended to incorporate additional data sources. Planned treatment scale-up is likely to achieve 2020 WHO targets for HCV morbidity, but substantial efforts will be required to ensure that HCV testing and patient engagement are sufficiently high.

A Bayesian evidence synthesis approach to estimate disease prevalence in hard-to-reach populations: hepatitis C in New York City

Existing methods to estimate the prevalence of chronic hepatitis C (HCV) in New York City (NYC) are limited in scope and fail to assess hard-to-reach subpopulations with highest risk such as injecting drug users (IDUs). To address these limitations, we employ a Bayesian multi-parameter evidence synthesis model to systematically combine multiple sources of data, account for bias in certain data sources, and provide unbiased HCV prevalence estimates with associated uncertainty. Our approach improves on previous estimates by explicitly accounting for injecting drug use and including data from high-risk subpopulations such as the incarcerated, and is more inclusive, utilizing ten NYC data sources. In addition, we derive two new equations to allow age at first injecting drug use data for former and current IDUs to be incorporated into the Bayesian evidence synthesis, a first for this type of model. Our estimated overall HCV prevalence as of 2012 among NYC adults aged 20-59 years is 2.78% (95% CI 2.61-2.94%), which represents between 124,900 and 140,000 chronic HCV cases. These estimates suggest that HCV prevalence in NYC is higher than previously indicated from household surveys (2.2%) and the surveillance system (2.37%), and that HCV transmission is increasing among young injecting adults in NYC. An ancillary benefit from our results is an estimate of current IDUs aged 20-59 in NYC: 0.58% or 27,600 individuals.

Enhanced Laws textures: A potential MRI surrogate marker of hepatic fibrosis in a murine model

PURPOSE

To compare enhanced Laws textures derived from parametric proton density (PD) maps to other MRI surrogate markers (T₂, PD, apparent diffusion coefficient (ADC)) in assessing degrees of liver fibrosis in an ex vivo murine model of hepatic fibrosis imaged using 11.7T MRI.

METHODS

This animal study was IACUC approved. Fourteen male, C57BL/6 mice were divided into control and experimental groups. The latter were fed a 3,5-dicarbethoxy-1,4-dihydrocollidine (DDC) supplemented diet to induce hepatic fibrosis. Ex vivo liver specimens were imaged using an 11.7T scanner, from which the parametric PD, T₂, and ADC maps were generated from spin-echo pulsed field gradient and multi-echo spin-echo acquisitions. A sequential enhanced Laws texture analysis was applied to the PD maps: automated dual-clustering algorithm, optimal thresholding algorithm, global grayscale correction, and Laws texture features extraction. Degrees of fibrosis were independently assessed by digital image analysis (a.k.a. %Area Fibrosis). Scatterplot graphs comparing enhanced Laws texture features, T₂, PD, and ADC values to degrees of fibrosis were generated and correlation coefficients were calculated.

RESULTS

Hepatic fibrosis and the enhanced Laws texture features were strongly correlated with higher %Area Fibrosis associated with higher Laws textures (r=0.89). Without the proposed enhancements, only a moderate correlation was detected between %Area Fibrosis and unenhanced Laws texture features (r=0.70). Correlation also existed between %Area Fibrosis and ADC (r=0.86), PD (r=0.65), and T₂ (r=0.66).

CONCLUSIONS

Higher degrees of hepatic fibrosis are associated with increased Laws textures. The proposed enhancements could improve the accuracy of Laws texture features significantly.

Tackling the burden of the hepatitis C virus in the UK: characterizing and assessing the clinical and economic consequences

OBJECTIVES

The hepatitis C virus (HCV) remains a significant public health issue. This study aimed to quantify the clinical and economic burden of chronic hepatitis C in the UK, stratified by disease severity, age and awareness of infection, with concurrent assessment of the impact of implementing a treatment prioritization approach.

STUDY DESIGN AND METHODS

A previously published back projection, natural history and cost-effectiveness HCV model was adapted to a UK setting to estimate the disease burden of chronic hepatitis C and end-stage liver disease (ESLD) between 1980 and 2035. A published meta-regression analysis informed disease progression, and UK-specific data informed other model inputs.

RESULTS

At 2015, prevalence of chronic hepatitis C is estimated to be 241,487 with 22.20%, 33.72%, 17.22%, 16.67% and 10.19% of patients in METAVIR stages F0, F1, F2, F3 and F4, respectively, but is estimated to fall to 193,999 by 2035. ESLD incidence is predicted to peak in 2031. Assuming all patients are diagnosed and treatment is prioritized in F3 and F4 using highly efficacious direct-acting antiviral (DAA) regimens, a 69.85% reduction in ESLD incidence is predicted between 2015 and 2035, and the cumulative discounted medical expenditure associated with the lifetime management of incident ESLD events is estimated to be £1,202,827,444.

CONCLUSIONS

The prevalence of chronic hepatitis C is expected to fall in coming decades; however, the ongoing financial burden is expected to be high due to an increase in ESLD incidence. This study highlights the significant costs of managing ESLD that are likely to be incurred without the employment of effective treatment approaches.

New treatments for hepatitis C virus (HCV): scope for preventing liver disease and HCV transmission in England

New direct-acting antivirals have the potential to transform the hepatitis C (HCV) treatment landscape, with rates of sustained viral response in excess of 90%. As these new agents are expensive, an important question is whether to focus on minimizing the consequences of severe liver disease, or reducing transmission via 'treatment as prevention'. A back-calculation model was used to estimate the impact of treatment of mild, moderate and compensated cirrhosis on incident cases of HCV-related end-stage liver disease/hepatocellular carcinoma (ESLD/HCC). In addition, a dynamic model was used to determine the impact on incidence and prevalence of chronic infection in people who inject drugs (PWID), the main risk group in England. Treating 3500 cirrhotics per year was predicted to reduce ESLD/HCC incidence from 1100 (95% CrI 970-1240) cases per year in 2015 to 630 (95% CrI 530-770) in 2020, around half that currently expected, although treating moderate-stage disease will also be needed to sustain this reduction. Treating mild-stage PWID was required to make a substantial impact on transmission: with 2500 treated per year, chronic prevalence/annual incidence in PWID was reduced from 34%/4.8% in 2015 to 11%/1.4% in 2030. There was little overlap between the two goals: treating mild stage had virtually no impact on ESLD/HCC within 15 years, but the long timescale of liver disease means relatively few PWID reach cirrhosis before cessation of injecting. Strategies focussing on treating advanced disease have the potential for dramatic reductions in severe morbidity, but virtually no preventative impact.

Where next for hepatitis B and C surveillance?

Hepatitis B and C infections are responsible for significant burden of disease accounting for 1.3 million deaths globally. There is a lack of quality data on the burden of disease due to these infections. One approach to informing policy makers on trends in hepatitis B and C is through case reporting of diagnosed cases. Data on these cases can identify outbreaks of hepatitis and monitor trends in acute and chronic infection. The European Centers for Disease Control (ECDC) has developed standardized case definitions and a harmonized reporting framework. Two articles in this issue summarize the trends in hepatitis B and C infection in Europe. The results show considerable variability in reported cases across countries, reflecting in part differences in testing practices. Risk factor information highlights the continued importance of injecting drug use as a risk factor for hepatitis C infection. Hepatitis case reporting provides valuable information, and more complete reporting will improve the utility of the data. For a comprehensive epidemiologic assessment of the burden of hepatitis, case reporting should be complemented by other sources of data, such as serologic and behavioural surveys.

Projections of the current and future disease burden of hepatitis C virus infection in Malaysia

Background

The prevalence of hepatitis C virus (HCV) infection in Malaysia has been estimated at 2.5% of the adult population. Our objective, satisfying one of the directives of the WHO Framework for Global Action on Viral Hepatitis, was to forecast the HCV disease burden in Malaysia using modelling methods.

Methods

An age-structured multi-state Markov model was developed to simulate the natural history of HCV infection. We tested three historical incidence scenarios that would give rise to the estimated prevalence in 2009, and calculated the incidence of cirrhosis, end-stage liver disease, and death, and disability-adjusted life-years (DALYs) under each scenario, to the year 2039. In the baseline scenario, current antiviral treatment levels were extended from 2014 to the end of the simulation period. To estimate the disease burden averted under current sustained virological response rates and treatment levels, the baseline scenario was compared to a counterfactual scenario in which no past or future treatment is assumed.

Results

In the baseline scenario, the projected disease burden for the year 2039 is 94,900 DALYs/year (95% credible interval (CrI): 77,100 to 124,500), with 2,002 (95% CrI: 1340 to 3040) and 540 (95% CrI: 251 to 1,030) individuals predicted to develop decompensated cirrhosis and hepatocellular carcinoma, respectively, in that year. Although current treatment practice is estimated to avert a cumulative total of 2,200 deaths from DC or HCC, a cumulative total of 63,900 HCV-related deaths is projected by 2039.

Conclusions

The HCV-related disease burden is already high and is forecast to rise steeply over the coming decades under current levels of antiviral treatment. Increased governmental resources to improve HCV screening and treatment rates and to reduce transmission are essential to address the high projected HCV disease burden in Malaysia.

Retrospective cohort study of liver transplantation in the United Kingdom between 1994 and 2010: the impact of hepatitis C infection

BACKGROUND

Liver transplantation is an important and established treatment option for chronic hepatitis C virus (HCV) related end-stage liver disease (HCV-related ESLD). This study describes trends in elective liver transplantation among persons with HCV-related ESLD.

STUDY DESIGN

Retrospective cohort.

METHODS

Analyses of United Kingdom (UK) Transplant Registry data for the period 1994 to 2010, with follow-up information extending to 2011.

RESULTS

Annual registrations for liver transplantation increased linearly and alcoholic liver cirrhosis (2075, 24%) and HCV-related ESLD (1213, 14%) were the most common indications. HCV-related ESLD patients were mainly aged 40-49 years (32%) and 50-59 years (43%); males (76%); and of white ethnicity (74%). Overall, 75% (956/1213) received a liver transplant with a linear increase over the period (OR 1.11, 95% CI 1.08, 1.13). Pre transplant mortality was unchanged (adjusted OR 1.0, 95% CI 0.96, 1.05) and post-transplant mortality decreased in both HCV-related (adjusted OR 0.77, 95% CI 0.68, 0.88) and non-HCV-related ESLD (adjusted OR 0.82, 95% CI 0.75, 0.89) patients.

CONCLUSION

The increase in demand for and receipt of liver transplants among persons with HCV-related ESLD requires coordinated efforts to increase not only organ donation, but investment in HCV prevention programmes and improved access to hepatitis C treatment services.

What is the impact of a country-wide scale-up in antiviral therapy on the characteristics and sustained viral response rates of patients treated for hepatitis C?

BACKGROUND & AIMS

The global burden associated with hepatitis C virus (HCV) infection has prompted a scale-up of antiviral therapy. Hitherto, no data exist on the impact of scaling-up, on the characteristics of treated populations, or on sustained viral response (SVR) rates. We assessed the country-wide scale-up of antiviral therapy in Scotland, a country which nationally monitors uptake of and response to HCV treatment.

METHODS

Data for patients, initiated on combined pegylated interferon and ribavirin therapy at 13 specialist HCV clinics in 2001-2010, were extracted from the Scottish HCV Clinical Database (n=3895). Patient characteristics included age, genotype, PWID (people who inject drugs) status, prison referral, and diagnosed cirrhosis. Temporal trends in covariates and adjusted effects on a SVR were examined via mixed-effects regression.

RESULTS

The number of patients starting treatment increased from 237 in 2001-2002 to 1560 in 2009-2010, with an increasing trend in SVR from 44% to 57% over this period. For a given clinic, between 2001/2 and 2010 there was a decrease in the odds of those treated being diagnosed with cirrhosis (odds ratio [OR]=0.84 per year), and increasing temporal trends for those treated being PWID (OR=1.08) and prison referrals (OR=1.06). Adjusting for covariates, the proportion of a given clinic's patients achieving SVR was positively associated with the percentage of PWID (OR=1.01 per percent increase; 95% confidence interval [CI]: 1.00-1.02) and genotype 2/3 (OR=1.03; 95% CI: 1.02-1.04).

CONCLUSIONS

Despite changes in patient characteristics, a country-wide scale-up of antiviral therapy did not compromise SVR rates. Results are highly relevant to countries planning on scaling-up treatment, given the forthcoming availability of new interferon-free therapies.

Estimated prevalence of Hepatitis C Virus infection in Canada, 2011

Background

Prevalence estimates contribute to our understanding of the magnitude of a particular health condition and in planning appropriate public health interventions.

Objective

To estimate the prevalence of chronic Hepatitis C virus (HCV) infection, anti-HCV-positive status (anti-HCV) and the proportion of undiagnosed HCV infections in Canada.

Methods

A combination of back-calculation and workbook methods was used. The back-calculation method estimated prevalent chronic HCV infection and the proportion undiagnosed using the Canadian Cancer Registry's data on hepatocellular carcinoma reported between 1992 and 2008 and the Canadian Notifiable Disease Surveillance System's data on Hepatitis C virus (HCV) cases reported between 1991 and 2009 in a Markov multi-state disease progression model with parameters adjusted to Canada. The workbook method divided the total population of Canada into population subsets and developed estimates of population size and anti-HCV prevalence for each. Sub-population size estimates were multiplied by anti-HCV prevalence measures to calculate the prevalence of anti-HCV by sub-population. A measure of spontaneous clearance was used to estimate the number of persons with chronic HCV from estimates of the number of anti-HCV-positive persons.

Results

The back-calculation method estimated the prevalence of chronic HCV infection at 0.64% and the proportion of undiagnosed chronic HCV infection at 44% in 2011. The workbook method estimated the anti-HCV prevalence at 0.96% (plausibility range: 0.61% to 1.34%) and chronic HCV infection at 0.71% (0.45 - 0.99%).

Interpretation

By combining mid-point estimates from both methods, it is estimated that between 0.64% to 0.71% of the overall Canadian population was living with chronic HCV infection in 2011 and 44% of these individuals were undiagnosed.

Review article: liver transplantation for hepatocellular carcinoma - a critical appraisal of the current worldwide listing criteria

BACKGROUND

Liver transplantation (LT) plays an important role in the management of patients with hepatocellular carcinoma (HCC). Although early results following LT for HCC were poor, since the introduction of the Milan criteria in 1996 morphological criteria have since been well established. Thereafter, various expansions of the Milan criteria were introduced worldwide. Listing criteria for LT for HCC in the United Kingdom (UK) initially conformed to the Milan criteria but were re-defined in 2009 by expansion of the Milan criteria.

AIMS

To look at the evidence in literature on listing criteria and management of HCC worldwide in comparison with the UK. Secondly, we aim to review worldwide vs. UK literature on prioritisation models, loco-regional therapy protocols and role of alpha-fetoprotein (AFP) in LT for HCC.

METHODS

An electronic literature search with Medline was carried out to identify articles related to LT for HCC.

RESULTS

Although various expansions of the Milan criteria have been described, they remain the gold standard against which other criteria are measured. The UK criteria are an expansion of the Milan criteria that go beyond Milan and University of California, San Francisco (UCSF) criteria. The current UK listing criteria for LT for HCC when compared to the worldwide criteria have a worse survival benefit (projected 5-year survival between 35-50%) when plotted on the metroticket calculator.

CONCLUSIONS

In keeping with most transplant centres worldwide, the UK have adopted expansions to Milan to allow more patients to benefit from LT. However, currently, as it stands the UK criteria when plotted in the modification of the Metroticket model project worse survival that would seem unjustified.

Increased uptake and new therapies are needed to avert rising hepatitis C-related end stage liver disease in England: modelling the predicted impact of treatment under different scenarios

BACKGROUND & AIMS

Hepatitis C (HCV) related disease in England is predicted to rise, and it is unclear whether treatment at current levels will be able to avert this. The aim of this study was to estimate the number of people with chronic HCV infection in England that are treated and assess the impact and costs of increasing treatment uptake.

METHODS

Numbers treated were estimated using national data sources for pegylated interferon supplied, dispensed, or purchased from 2006 to 2011. A back-calculation approach was used to project disease burden over the next 30 years and determine outcomes under various scenarios of treatment uptake.

RESULTS

5000 patients were estimated to have been treated in 2011 and 28,000 in total from 2006 to 2011; approximately 3.1% and 17% respectively of estimated chronic infections. Without treatment, incident cases of decompensated cirrhosis and hepatocellular carcinoma were predicted to increase until 2035 and reach 2290 cases per year. Treatment at current levels should reduce incidence by 600 cases per year, with a peak around 2030. Large increases in treatment are needed to halt the rise; and with more effective treatment the best case scenario predicts incidence of around 500 cases in 2030, although treatment uptake must still be increased considerably to achieve this.

CONCLUSIONS

If the infected population is left untreated, the number of patients with severe HCV-related disease will continue to increase and represent a substantial future burden on healthcare resources. This can be mitigated by increasing treatment uptake, which will have the greatest impact if implemented quickly.

Living with hepatitis C: a phenomenological study

AIMS AND OBJECTIVES

To explore the experience of adults living with hepatitis C over time.

BACKGROUND

Hepatitis C virus is a growing problem affecting thousands of people worldwide. The majority of individuals infected develop chronic liver disease, but treatment is not always successful, leaving many to live with the virus indefinitely. Experiences of living with hepatitis C are poorly understood yet essential to meet the needs of an increasing number of affected people.

DESIGN

A qualitative study using a descriptive phenomenological methodology.

METHODS

Unstructured interviews were conducted with 23 hepatitis C-positive individuals in the East of England; participants were interviewed twice within a year.

RESULTS

Data analysis revealed six themes of the experience of living with hepatitis C: hepatitis C and self; hepatitis C, self and others; self and handling hepatitis C; self and handling hepatitis C treatment issues; living with the consequences of hepatitis C; self, hepatitis C and thoughts of the future.

CONCLUSIONS

Diagnosis of hepatitis C can disrupt people's sense of identity and trigger a life transition. A complex range of factors create uncertainty for people living with hepatitis C. Many struggle to make a healthy transition to life with the condition, instead living in a state of sustained uncertainty.

RELEVANCE TO CLINICAL PRACTICE

Nurses working within a chronic care framework of ongoing advice and support can improve experiences for those living with hepatitis C. Practice aimed at reducing both the disruptive effect of the diagnosis and the uncertainties it creates can help facilitate a transition to life with the disease.

The cost of treatment failure: resource use and costs incurred by hepatitis C virus genotype 1-infected patients who do or do not achieve sustained virological response to therapy

Chronic hepatitis C virus (HCV) infection places a considerable economic burden on health services. Cost-effectiveness analyses of antiviral treatment for patients with chronic HCV infection are dependent on assumptions about cost reductions following sustained virological response (SVR) to therapy. This study quantified the medium-term difference in health resource usage and costs depending on treatment outcome. Retrospective chart review of patients with HCV genotype 1 infection who had received at least 2 months pegylated interferon and ribavirin therapy, with known treatment outcome was conducted. Disease status was categorized as chronic hepatitis, cirrhosis or decompensated liver disease. Health resource use was documented for each patient in each disease state. Unit costs were from the NHS 'Payment by Results' database and the British National Formulary. One hundred and ninety three patients (108 SVR, 85 non-SVR) with mean follow-up of 3.5 (SVR) and 4.9 (non-SVR) years were enrolled. No SVR patient progressed to a more severe liver disease state. Annual transition rates for non-SVR patients were 7.4% (chronic hepatitis to cirrhosis) and 4.9% (cirrhosis to decompensated liver disease). By extrapolation of modelled data over a 5-year post-treatment period, failure of patients with chronic hepatitis to achieve SVR was associated with a 13-fold increase (roughly £2300) in costs, whilst for patients who were retreated, the increase was 56-fold, equating to more than £10 000. Achievement of an SVR has significant effects on health service usage and costs. This work provides real-life data for future cost-effectiveness analyses related to the treatment for chronic HCV infection.

Incidence and mortality of primary liver cancer in England and Wales: Changing patterns and ethnic variations

AIM: To explore recent trends, modes of diagnosis, ethnic distribution and the mortality to incidence ratio of primary liver cancer by subtypes in England and Wales.

METHODS: We obtained incidence (1979-2008) and mortality (1968-2008) data for primary liver cancer for England and Wales and calculated age-standardised incidence and mortality rates. Trends in age-standardised mortality (ASMR) and incidence (ASIR) rates and basis of diagnosis of primary liver cancer and subcategories: hepatocellular carcinoma, intrahepatic bile duct and unspecified liver tumours, were analysed over the study period. Changes in guidelines for the diagnosis of primary liver cancer (PLC) may impact changing trends in the rates that may be obtained. We thus explored changes in the mode of diagnosis as reported to cancer registries. Furthermore, we examined the distribution of these tumours by ethnicity. Most of the statistical manipulations of these data was carried out in Microsoft excel^® (Seattle, Washington, United Sttaes). Additional epidemiological statistics were done in Epi Info software (Atlanta, GA, United Sttaes). To define patterns of change over time, we evaluated trends in ASMR and ASIR of PLC and intrahepatic bile duct carcinoma (IHBD) using a least squares regression line fitted to the natural logarithm of the mortality and incidence rates. We estimated the patterns of survival over subsequent 5 and 10 years using complement of mortality to incidence ratio (1-MIR).

RESULTS: Age-standardised mortality rate of primary liver cancer increased in both sexes: from 2.56 and 1.29/100000 in 1968 to 5.10 and 2.63/100000 in 2008 for men and women respectively. The use of histology for diagnostic confirmation of primary liver cancer increased from 35.7% of registered cases in 1993 to plateau at about 50% during 2005 to 2008. Reliance on cytology as a basis of diagnosis has maintained a downward trend throughout the study period. Although approximately 30% of the PLC registrations had information on ethnicity, there was a relatively higher registration of the major tumour subtypes in patients whose ethnic backgrounds were from high incident regions of the world. Survival from PLC is estimated to get poorer in 10 years (2018) relative to 2008, particularly as a result of IHBD.

CONCLUSION: Incidence and mortality of PLC, and particularly IHBD, have continued to rise in England and Wales. Changes in the modes of diagnosis may be contributing.

Progress towards a hepatitis C virus vaccine

New drugs to treat hepatitis C are expected to be approved over the next few years which promise to cure nearly all patients. However, due to issues of expected drug resistance, suboptimal activity against diverse hepatitis C virus (HCV) genotypes and especially because of their extremely high cost, it is unlikely that these HCV drugs will substantially reduce the world's HCV carrier population of around 170 million in the near future or the estimated global incidence of millions of new HCV infections. For these reasons, there is an urgent need to develop a prophylactic HCV vaccine and also to determine if therapeutic vaccines can aid in the treatment of chronically infected patients. After much early pessimism on the prospects for an effective prophylactic HCV vaccine, our recent knowledge of immune correlates of protection combined with the demonstrated immunogenicity and protective animal efficacies of various HCV vaccine candidates now allows for realistic optimism. This review summarizes the current rationale and status of clinical and experimental HCV vaccine candidates based on the elicitation of cross-neutralizing antibodies and broad cellular immune responses to this highly diverse virus.

Estimating the Incidence and Prevalence of Chronic Hepatitis C Infection in Taiwan Using Back Projection

OBJECTIVE

Hepatitis C virus (HCV) infection is the leading cause of liver disease, and Taiwan has among the highest prevalence of HCV infection in the general population in Northeast Asia, estimated at between 2% and 4%. The aim of this study was to estimate the number of patients living with chronic HCV infection in Taiwan and quantify the expected numbers in each of the five Metavir fibrosis stages.

METHODS

We applied a back-projection approach, using observed hepatocellular carcinoma incidence between 1979 and 2008 and a smoothed Expectation-Maximization algorithm to maximize a Poisson likelihood to estimate the previous incidence of HCV infection. The algorithm was coded in Excel and combined with the MOdelling the NAtural histoRy and Cost-effectiveness of Hepatitis model (a hepatitis C natural history markov model) to predict the past and future numbers in each Metavir fibrosis stage.

RESULTS

Incident cases were predicted to have peaked in 1972 at 56,634 annually, with the prevalence peaking in 1986 at 763,737 infections and falling to 578,203 infections in 2012. It was estimated that in 2012, 127,795 (23.0%), 105,545 (19.0%), 81,211 (14.6%), 123,939 (22.3%), and 116,823 (21.1%) subjects were in fibrosis stages F0, F1, F2, F3, and F4, respectively.

DISCUSSION

Our study provides HCV infection prevalence estimates, stratified by Metavir fibrosis stage, in Taiwan for 2012. This has potential implications for budget planning, particularly with the availability of emerging therapies because fibrosis stage is predictive of both rapid and sustained virological response; therefore, planning expected treatment response in a given population could be enhanced with this additional information.

Effectiveness of Methadone Maintenance Treatment in Prevention of Hepatitis C Virus Transmission among Injecting Drug Users

BACKGROUND

Injecting drug users (IDUs) are a major and most important risk factor for rising hepatitis C virus (HCV) prevalence in Iran.

OBJECTIVES

The objective of this study was to determine the effectiveness of methadone maintenance treatment (MMT) in prevention of HCV infection transmission among IDUs.

PATIENTS AND METHODS

A mathematical modeling has been used to estimate number of HCV infections averted. The input parameters used in the model were collected by self-reported method from 259 IDUs before registering and one year after MMT. Nonparametric statistical tests have been used to compare risky injecting and sexual behaviors among IDUs before and after participating in MMT program. Deterministic sensitivity analyses were done to show the effects of parameters' uncertainty on outcome.

RESULTS

Of the 259 participants, 98.4% (255) were men, the mean age ± SD was 33.1 ± 7.58 years and HCV prevalence was 50%. The studied IDUs reported lower rate of risky injecting and sexual behavior after participation in MMT program. The cumulative incidence of HCV per 100 IDUs due to sharing injection and unsafe sexual contact with MMT program were 13.84 (95% CI: 6.17 -21.51), 0.0003 (0.0001 - 0.0005) and without it 36.48 (25.84 - 47.11) and 0.0004 (0.0002-0.0006) respectively.

CONCLUSIONS

The MMT program is an effective intervention to prevent HCV infection transmission, although it is essential to compare its effectiveness with other interventions before implementing it in nationwide.

No beneficial effect of all-trans retinoic acid in previous non-responder patients with chronic hepatitis C: the ATRACTION study, a phase II randomised trial

BACKGROUND

Preclinical data suggested all-trans retinoic acid (tretinoin) as a potential antiviral agent against chronic hepatitis C infection.

AIMS

To assess efficacy, safety, and tolerability of tretinoin in combination with peg-interferon and ribavirin in genotype-1 infected patients with prior non-response.

METHOD

We performed an open-label multicentre clinical trial. Patients were randomised to either receive additional tretinoin (45mg/m(2)/day) for 12 weeks (arm A), or peg-interferon and ribavirin alone (arm B). Primary endpoint was the slope of the third phase of viral decline (Mδ) as determined in an established kinetic model known to correlate with treatment outcome. Secondary endpoints were additional kinetic parameters, viral response rates, safety, and tolerability.

RESULTS

27 patients in arm A and 30 patients in arm B were treated per protocol until week 12. Viral kinetic parameters did not differ. Rates of early virological response (>2log10 drop at week 12) were similar (10/27 versus 11/30 patients). In arm A, patients experienced a higher rate and intensity of adverse events, most commonly skin and mucosal dryness, and headache.

CONCLUSION

Addition of tretinoin was safe and acceptably well tolerated. However, it did not influence viral kinetics and thus cannot be further considered as a treatment option.

The burden of liver disease in Europe: a review of available epidemiological data

To survey the burden of liver disease in Europe and its causes 260 epidemiological studies published in the last five years were reviewed. The incidence and prevalence of cirrhosis and primary liver cancer are key to understand the burden of liver disease. They represent the end-stage of liver pathology and thus are indicative of the associated mortality. About 0.1% of Hungarian males will die of cirrhosis every year compared with 0.001% of Greek females. WHO estimate that liver cancer is responsible for around 47,000 deaths per year in the EU. Harmful alcohol consumption, viral hepatitis B and C and metabolic syndromes related to overweight and obesity are the leading causes of cirrhosis and primary liver cancer in Europe. Chronic hepatitis B affects 0.5-0.7% of the European population. In the last decade the prevalence of chronic hepatitis C was 0.13-3.26%. It is of great concern that about 90% of people in Europe infected by viral hepatitis are unaware of their status. Available data suggest the prevalence rate of NAFLD is 2-44% in the general European population (including obese children) and 42.6-69.5% in people with type 2 diabetes. Each of these four major causes of liver disease is amenable to prevention and treatment, reducing the burden of liver disease in Europe and saving lives. Further surveys are urgently needed to implement cost-effective prevention programmes and novel treatments to tackle this problem.

The burden of hepatitis C in Europe from the patients' perspective: a survey in 5 countries

BACKGROUND

Few studies have examined the impact of Hepatitis C virus (HCV) infection on patient reported outcomes in Europe. This study was conducted to assess the burden of HCV infection in terms of work productivity loss, activity impairment, health-related quality of life, healthcare resource utilization, and associated costs.

METHODS

The 2010 European National Health and Wellness Survey (n = 57,805) provided data. Patients reporting HCV infection in France, Germany, the UK, Italy, and Spain were matched to respondents without HCV using propensity scores. Outcome measures included the Work Productivity and Activity Impairment (WPAI) questionnaire and the Medical Outcomes Study Short Form-12 (SF-12v2) questionnaire. Subgroup analyses focused on treatment-naïve patients.

RESULTS

HCV Patients (n = 286) had more work impairment (30% vs. 18%, p < .001), more impairment in non-work activities (34% vs. 28%, p < .05), and more annual physician visits per patient (19.8 vs. 13.3, p < .001). Estimated indirect and direct costs were €2,956 (p < .01) and €495 (p < .001) higher than in matched controls, respectively. Health-related quality of life was also lower among HCV patients. Treatment-naïve HCV patients (n = 139) also reported higher work impairment (29% vs. 15%, p < .01), as well as more frequent physician visits (19.5 vs. 12.1, p < .01) than matched controls. Each treatment-naïve HCV infected patient incurred €934 in direct costs vs. €508 (p < .01 in matched controls. Employed treatment-naïve patients reported higher productivity loss per year compared to matched controls (€6,414 vs. €3,642, p < .05).

CONCLUSION

HCV infection in Europe is associated with considerable economic and humanistic burden. This is also true of diagnosed patients who have never been treated for HCV.

Improved hepatitis C treatment response in younger patients: findings from the UK HCV National Register cohort study

In a cohort of 272 treatment-naive individuals with chronic hepatitis C infection acquired on a known date who were enrolled in the UK HCV National Register, a progressive improvement in response to treatment was found with the evolution of antiviral therapies from 20% (25/122) for interferon monotherapy to 63% (55/88) for pegylated interferon+ribavirin therapy. Multivariable analysis results showed increasing age to be associated with poorer response to therapy [odds ratio (OR) 0·84, 95% confidence interval (CI) 0·72-0·99, P=0·03] whereas time since infection was not associated with response (OR 0·93, 95% CI 0·44-1·98, P=0·85). Other factors significantly associated with a positive response were non-type 1 genotype (P<0·0001) and combination therapies (P<0·0001). During the first two decades of chronic HCV infection, treatment at a younger age was found to be more influential in achieving a sustained viral response than treating earlier in the course of infection.

Public health issues of hepatitis C virus infection

Hepatitis C virus (HCV) is a leading cause of liver disease worldwide, as 130-170 million individuals are chronically infected and 350,000 patients die every year from HCV infection. The HCV prevalence varies widely among countries being highest in several African and Eastern Mediterranean countries. The incidence of new HCV infections may be declining in developed countries, but there is still a large reservoir of chronic infections. The most important mode of HCV transmission has been injecting drug use in developed countries with low prevalence and unsafe therapeutic injections in developing countries with moderate-high prevalence. Since there are no systematic screening policies, most patients remain undiagnosed. Even among diagnosed patients, a minority receives treatment due to several barriers to therapy. Given the high efficacy of treatment, public health authorities should recognise the importance of HCV and make resources available for the implementation of effective primary prevention, screening and management policies.

Outcome of hepatitis C virus infection in Chinese paid plasma donors: a 12-19-year cohort study

BACKGROUND AND AIMS

Commercial plasma donation was introduced in China in the 1970s. Cases of non-A, non-B hepatitis (hepatitis C) continued to occur, with multiple outbreaks among plasma donors in Guan county, Hebei province between 1972 and 1990. The outcomes of hepatitis C virus (HCV) infection in these paid plasma donors from six villages of Guan county were followed up for 12-19 years.

METHODS

A total of 402 plasma donors with HCV infection were enrolled since anti-HCV-positive in 1991 or 1998. Follow up was maintained until death or the end of the observation period. No antiviral treatment was applied during the period of infection.

RESULTS

Follow up was lost in 23 cases. After a 12-19-year follow up, 31 donors died, with the cause of death directly related to liver disease in 15 cases, and an overall mortality of 8.18% (31/379). The incidence of liver cirrhosis was 10.03%, and hepatocellular carcinoma (HCC) was 2.90%. The rate of viral spontaneous clearing was 20.32% (77/379), and 13.69% (23/168) in males and 25.59% (54/211) in females. In May 2010, detections were performed in 348 cases. Abnormality of liver function was related to HCV viremia. Sex and alcohol intake impacted the outcome of HCV infection. There was no correlation between the viral spontaneous clearance with age of infection and genotype.

CONCLUSIONS

This area has a high rate of chronicity in HCV infection due to plasma donation. Twenty-five years after virus infection, liver cirrhosis or HCC developed in one-tenth of patients, with an overall mortality of 8.18%.

IL28B genetic variants and gender are associated with spontaneous clearance of hepatitis C virus infection

Single nucleotide polymorphisms (SNPs) near the IL28B gene have been shown to be associated with response to treatment for chronic hepatitis C and also with spontaneous clearance of hepatitis C virus (HCV) infection. We analysed the association between IL28B genetic variants and spontaneous clearance of HCV infection in 376 HCV-infected Chinese paid plasma donors. Genotyping of eight SNPs near the IL28B region was performed by the iPLEX system (MassARRAY(®) SNP Genotyping; Sequenom) in all donors, and sequencing was performed on all 80 donors who cleared HCV and on 160 of 296 donors who did not clear HCV to validate the genotypes. Eighty (21.3%) donors spontaneously cleared HCV. Four SNPs were significantly associated with spontaneous HCV clearance: rs8099917 TT (vs GT), rs8105790 TT (vs CT), rs12980275 AA (vs AG) and rs10853728 CC (vs CG or GG) with OR (95% CI) 15.27 (2.07-112.50), 14.88 (2.02-109.72), 7.92 (1.88-33.32) and 2.32 (1.22-4.42) respectively. No association between the other four IL28B SNPs including rs12979860 and spontaneous HCV clearance was found. Women had a higher rate of spontaneous HCV clearance than men [56/213 (26.3%) vs 24/163 (14.6%), P = 0.007], and this was true even after stratification for IL28B genotypes with OR of 1.9-2.2 among those with favourable genotypes. Our results confirmed that IL28B polymorphism is associated with spontaneous clearance of HCV in Chinese subjects, but the SNPs that predict HCV clearance in Chinese subjects were different from those reported in Caucasians. Women were more likely to clear HCV infection regardless of IL28B genotypes.

Structural frameworks and key model parameters in cost-effectiveness analyses for current and future treatments of chronic hepatitis C

OBJECTIVES

Published economic evaluations have reported available treatments for chronic hepatitis C to be cost-effective as part of the current approach to disease management, but as standards of care evolve, their approach to modeling should be reconsidered. This study aimed to review structural frameworks and key model parameters as reported in current economic evaluations for treatments for chronic hepatitis C, and model the impact of variability across parameters on results.

METHODS

A systematic review of studies published from 2000 to 2011 was performed. Studies were retrieved from five electronic databases using relevant search strategies. Model structures, disease progression rates, utilities, and costs were extracted from included studies, and were qualitatively reviewed and incorporated into a cost-utility model.

RESULTS

Thirty-four studies were appropriate for data extraction. A common pathway of six disease states was identified. In some studies the early disease stages and/or the decompensated cirrhosis state were further subdivided. Large variability in values used for disease progression rates, utilities, and costs were identified. When incorporated into a model, incremental cost-effectiveness ratios (ICERs) varied: in the least favorable scenario, peginterferon plus ribavirin was dominated by interferon plus ribavirin; and in the most favorable scenario, peginterferon plus ribavirin dominated interferon plus ribavirin ($8,544 per quality-adjusted life year [QALY]; costs are given in 2008 US dollar amounts). Using mean values the ICER was $15,198 per QALY.

CONCLUSIONS

Current models use a simplistic structure resulting from the lack of available data reflecting patient heterogeneity. Key model parameters are currently based on a small number of studies and the variability across these values can affect the interpretation of results.

The impact of needle and syringe provision and opiate substitution therapy on the incidence of hepatitis C virus in injecting drug users: pooling of UK evidence

AIMS

To investigate whether opiate substitution therapy (OST) and needle and syringe programmes (NSP) can reduce hepatitis C virus (HCV) transmission among injecting drug users (IDUs).

DESIGN

Meta-analysis and pooled analysis, with logistic regression allowing adjustment for gender, injecting duration, crack injecting and homelessness.

SETTING

Six UK sites (Birmingham, Bristol, Glasgow, Leeds, London and Wales), community recruitment.

PARTICIPANTS

A total of 2986 IDUs surveyed during 2001-09.

MEASUREMENT

Questionnaire responses were used to define intervention categories for OST (on OST or not) and high NSP coverage (≥100% versus <100% needles per injection). The primary outcome was new HCV infection, measured as antibody seroconversion at follow-up or HCV antibody-negative/RNA-positive result in cross-sectional surveys.

FINDINGS

Preliminary meta-analysis showed little evidence of heterogeneity between the studies on the effects of OST (I2=48%, P=0.09) and NSP (I2=0%, P=0.75), allowing data pooling. The analysis of both interventions included 919 subjects with 40 new HCV infections. Both receiving OST and high NSP coverage were associated with a reduction in new HCV infection [adjusted odds ratios (AORs)=0.41, 95% confidence interval (CI): 0.21-0.82 and 0.48, 95% CI: 0.25-0.93, respectively]. Full harm reduction (on OST plus high NSP coverage) reduced the odds of new HCV infection by nearly 80% (AOR=0.21, 95% CI: 0.08-0.52). Full harm reduction was associated with a reduction in self-reported needle sharing by 48% (AOR 0.52, 95% CI: 0.32-0.83) and mean injecting frequency by 20.8 injections per month (95% CI: -27.3 to -14.4).

CONCLUSIONS

There is good evidence that uptake of opiate substitution therapy and high coverage of needle and syringe programmes can substantially reduce the risk of hepatitis C virus transmission among injecting drug users. Research is now required on whether the scaling-up of intervention exposure can reduce and limit hepatitis C virus prevalence in this population.

Impact of delayed diagnosis time in estimating progression rates to hepatitis C virus-related cirrhosis and death

Delay of the diagnosis of hepatitis C virus (HCV), and its treatment to avert cirrhosis, is often present sincethe early stage of HCV progression is latent. Current methods to determine the incubation time to HCV-related cirrhosis and the duration time from cirrhosis to subsequent events (e.g. complications or death) used to be based on the time of liver biopsy diagnosis and ignore this delay which led to an interval censoring for the first event time and a double censoring for the subsequent event time. To investigate the impact of this delay in estimating HCV progression rates and relevant estimating bias, we present a correlated two-stage progression model for delayed diagnosis time and fit the developed model to the previously studied hepatitis C cohort data from Edinburgh. Our analysis shows that taking the delayed diagnosis into account gives a mildly different estimate of progression rate to cirrhosis and significantly lower estimated progression rate to HCV-related death in comparison with conventional modelling. We also find that when the delay increases, the bias in estimating progression increases significantly.

Evolving epidemiology of hepatitis C virus

More than 20 years after the discovery of the hepatitis C virus (HCV), it is now well established that HCV is of global importance affecting all countries, leading to a major global health problem that requires widespread active interventions for its prevention and control. Chronic hepatitis C was linked to the development of cirrhosis and hepatocellular carcinoma in many areas of the world. Current epidemiological assessments have identified complex patterns with highly variable local prevalence rates between countries and within countries. HCV infection patterns have not significantly changed in most parts of the world since 1997, when first analyzed, partly due to the lack of new and more accurate data. The assessment of the national HCV prevalence and transmission modes should be completed to enable national authorities to prioritize preventive measures and to make the most appropriate use of available resources. The 'patchy' epidemiological situation in some areas will continue to complicate the task of the establishment of global, regional and national base line data. The present assessment finds a global prevalence of 2.35%, affecting 160 million chronically infected individuals. There is an urgent need for more accurate Information on the costs and burden of HCV to society. Twenty-one year after the discovery of HCV, the assessment is far from being complete and little progress has been made in the past 10 years in many countries. In some countries significant increases have been reported and this may also apply to countries were insufficient data exist. A safe and efficient vaccine against HCV is urgently needed.

Total and cause-specific mortality rates in a prospective study of community-acquired hepatitis C virus infection in northern Norway

Knowledge of the natural course and especially the total and cause-specific mortality of community-acquired chronic HCV infection is limited. The aims of our study were to determine the total and cause-specific mortality in patients infected with chronic hepatitis C in a community-based setting in northern Norway. This prospective cohort study included 1010 HCV-positive patients diagnosed with recombinant immunoblot assay between 1 January 1990 and 1 January 2000, with a median observation time from diagnosis to follow-up of 7 years. Data were collected from medical records in the period between 1 January 2004 and 30 June 2006. Time and cause of death were ascertained from the Norwegian Causes of Death Register. Age-adjusted death rates and standardised mortality ratios (SMRs) were compared with those of the general Norwegian population. In total, 122 deaths were recorded. The Kaplan-Meier estimate of survival was 88% at 14 years. The SMR in the cohort relative to the general population was 6.66. Most of the excess deaths in both genders were because of liver-related causes, those associated with a drug-using lifestyle and suicide. The statistically significant increase in SMRs ranged from 4.2 for death by cancer in women to 64.6 for liver disease in women. There was no statistically significant increase in SMRs from cardiovascular disease in either gender or from cancer in men. In conclusion, our study shows that the death rate in patients infected with hepatitis C is 6.66 times higher than in the general Norwegian population.

The burden of hepatitis C in Sweden: a national study of inpatient care

The spread of hepatitis C virus (HCV) in Sweden in the 1970s indicated that serious liver complications (SLC) would increase in the 2000s. The aim of this study was to analyse the burden of HCV-associated inpatient care in Sweden, to demonstrate the changes over time and to compare the findings with a noninfected population. The HCV-cohort (n: 43,000) was identified from the national surveillance database 1990-2006, and then linked to national registers to produce an age-, sex-, and region-matched noninfected comparison population (n: 215,000) and to obtain information on demographics, cancers, inpatient care and prescriptions. Cox regression was used to estimate the likelihood (hazard ratios) for admission to hospital in the HCV compared with the noninfected cohort. The hazard ratios were 4.03 (95% CI: 3.98-4.08) for all care, 77.52 (71.02-84.60) for liver-related care and 40.74 (30.58-54.27) for liver cancer care. The admission rate in the HCV-cohort compared with the noninfected cohort, the rate ratio (age- and sex-adjusted) for all inpatient care was 5.91 (95% CI: 5.87-5.94), and the rate ratio for liver-related care was 70.05 (66.06-74.28). In the HCV-cohort, 45% of all episodes were for psychiatric, mostly drug-related, care. Inpatient care for SLC increased in the 2000s. To conclude, drug-related care was common in the HCV-infected cohort, the demand for liver-related care was very high, and SLC increased notably in the 2000s, indicating that the burden of inpatient care from serious liver disease in HCV-infected individuals in Sweden is an increasing problem.

The development and implementation of a nurse-led hepatitis C protocol for people with serious mental health problems

Hepatitis C (HCV) is a significant health issue for people with serious mental health problems (SMHP). Factors associated with this include high rates of substance use, injecting drug use, and lack of knowledge regarding the transmission and prevention of HCV. This population are at higher risk of experiencing conditions where transmission rates are high, e.g. night shelters and homelessness. People with SMHP also often have factors associated with acceleration of the disease, including excessive alcohol use and poor physical health. Nurses across services collaborated to develop and implement a protocol to address the needs of clients of an Assertive Outreach Team with or at risk of HCV. It has been successful in developing an effective approach to addressing the needs of people with or at risk of HCV and serious mental health problems. It guides staff in providing a flexible, accessible service for clients delivered across organizational boundaries. It has demonstrated improved health outcomes for clients. It is believed that this project can be used as a template to address other health needs of this client group for example diet, obesity and smoking.

Clinical outcomes in a prospective study of community-acquired hepatitis C virus infection in Northern Norway

OBJECTIVE

Knowledge on the natural course of the morbidity of unselected community-acquired hepatitis C virus (HCV) infection is limited. The aim of our study was to characterize the clinical outcomes of both hepatic and extrahepatic morbidity in patients infected with HCV in a community-based setting in Northern Norway.

MATERIAL AND METHODS

This prospective cohort study included 1010 HCV-positive patients diagnosed by recombinant immunoblot assay (RIBA), between 1 January 1990 and 1 January 2000. Questionnaires were sent to those physicians in Northern Norway who had requested the RIBA tests during the relevant period. Data were collected from medical records in the period between 1 January 2004 and 30 June 2006. Access to confidential information was obtained from the Norwegian Directorate of Health.

RESULTS

Median age at follow-up was 39 and 41 years in females and males, respectively. In patients with positive HCV RNA status following results were found: Alanine aminotransferase was elevated in 27.4%, decompensated liver disease in 2.9% and hepatocellular carcinoma in 0.4%. Median observation period from estimated acquisition of the disease to follow-up in these patients was 26 years. Depression was reported in 10.7% of chronic infected subjects. Renal failure caused by membranoproliferative glomerulonephritis occurred in 0.2%.

CONCLUSIONS

In an unselected HCV-RNA positive population severe liver disease developed in a sub-group of patients. These observations suggest that chronic HCV disease in relatively young subjects may cause a substantial burden on the health system in the future.

Prognosis of hepatitis C virus-infected Canadian post-transfusion compensation claimant cohort

Accurate prognostic estimates were required to ensure the sufficiency of the $1.1 billion compensation fund established in 1998 to compensate Canadians who acquired hepatitis C virus (HCV) infection through blood transfusion between 1986 and 1990. This article reports the application of Markov modelling and epidemiological methods to estimate the prognosis of individuals who have claimed compensation. Clinical characteristics of the claimant cohort (n = 5004) were used to define the starting distribution. Annual stage-specific transition probabilities (F0-->F1, . . ., F3-->F4) were derived from the claimants, using the Markov maximum likelihood estimation method. HCV treatment efficacy was derived from the literature and practice patterns were estimated from a national survey. The estimated stage-specific transition probabilities of the cohort between F0-->F1, F1-->F2, F2-->F3 and F3-->F4 were 0.032, 0.137, 0.150 and 0.097 respectively. At 20 years after the index transfusion, approximately 10% of all living claimants (n = 3773) had cirrhosis and 0.5% developed hepatocellular carcinoma (HCC). For nonhaemophilic patients, the predicted 20-year (2030) risk of HCV-related cirrhosis was 23%, and the risk of HCC and liver-related death was 7% and 11% respectively. Haemophilic patients who are younger and are frequently co-infected with human immunodeficiency virus would have higher 20-year risks of cirrhosis (37%), HCC (12%) and liver-related death (19%). Our results indicate that rates of progression to advanced liver disease in post-transfusion cohorts may be lower than previously reported. The Canadian post-transfusion cohort offers new and relevant prognostic information for post-transfusion HCV patients in Canada and is an invaluable resource to study the natural history and resource utilization of HCV-infected individuals in future studies.

Cost-effectiveness of pegylated interferon and ribavirin for patients with chronic hepatitis C treated in routine clinical practice

OBJECTIVES

This study assesses whether pegylated interferon and ribavirin is cost-effective compared with no antiviral treatment provided in routine clinical practice, for different patient subgroups.

METHODS

The cost-effectiveness analysis (CEA) uses a Markov decision model to estimate the lifetime cost per quality-adjusted life-year (QALY) of antiviral treatment compared with no treatment. The model is populated with data on sustained virological responses, costs, and transition probabilities all taken from a large representative sample of UK cases and centers (Trent HCV database).

RESULTS

The CEA found that pegylated interferon and ribavirin was cost-effective for most patient subgroups. The CEA found that for patients with genotype non-1, the intervention led to cost reductions and gains of at least 0.5 QALYs. For genotype 1 cases with mild or moderate disease, and younger cirrhotic patients (aged 40 or less), costs per QALY remained below 20,000 pound sterling ($40,000 or 29,000 euro). For genotype 1 cases with cirrhosis aged 50, the mean cost per QALY rose to over 60,000 pound sterling ($120,000 or 87,000 euro).

CONCLUSIONS

The study concludes that, based on cost and effectiveness data collected from routine clinical practice, treatment with pegylated interferon and ribavirin is generally cost-effective. The study shows that there are variations according to patient subgroup and for older (aged 50 or over) genotype 1 patients with cirrhosis, antiviral treatment appears less cost-effective.

Estimating hepatitis C infection acquired in England, 1986–2000

Hepatitis C is a global health problem and in the UK seroprevalence studies have mainly concentrated on specific high-risk groups. The aim of this study was to determine changes in the prevalence of antibody to hepatitis C virus in England using residual specimens collected between 1986 and 2000 reflecting the general population. A cross-sectional study design using a convenience collection of serum specimens from adult patients submitted to laboratories in the years 1986, 1991, 1996 and 2000 from a total of 19 laboratories around England were investigated. The main outcome was to determine anti-HCV prevalence and the average incidence occurring between 1986 and 2000 and factors associated with infection. Multivariable analysis of results from all years showed there was a significant difference in prevalence between males and females (P<0·001), birth cohort (P<0·001) and by health region (P<0·001). An average of 0·72% (95% CI 0–1·65%) of those susceptible to HCV born between 1950 and 1970 were estimated to have acquired the infection between 1986 and 2000. Analysis of this convenience serum collection suggests that HCV prevalence is low in the general population, and is associated with period of birth, gender and health region. There was evidence to support a low incidence of HCV infection in those born between 1950 and 1970 over the period 1986–2000 which, at the population level, equated to a substantial burden of infection (~106 000 persons). Continued surveillance and prevention targeted at injecting drug users are essential for the control of hepatitis C in the UK.

Addressing HCV infection in Europe: reported, estimated and undiagnosed cases

The hepatitis C virus (HCV) is a major public health problem due to its high prevalence, high rate of onward transmission and health complications. As many as 85% of people infected with HCV may go on to become chronic carriers of the disease with the risk of developing liver cancer or cirrhosis. At present, it is the most common cause of chronic liver disease and liver transplantation in a number of countries, with an estimated 250,000 people dying annually from HCV-related causes. Despite the magnitude of the problem, the virus does not receive adequate attention from either the general public or from health policy-makers. This study assesses HCV prevalence from both estimated totals and undiagnosed cases in selected European countries. Secondary sources were assessed and experts in 17 European countries were interviewed about HCV prevalence, reporting strategies and transmission. Available data suggest that only between 10% and 40% of people with HCV in Europe are aware of their infection (up to 90% of the prevalent pool are undiagnosed in such countries as Germany or Poland). Though the virus affects people of all ages, races and backgrounds, in Europe, between 20% and 90% of new HCV cases have been identified among past or current injecting drug users (IDUs). It is of the utmost importance to improve both public awareness and access to early testing and counselling, with the goal of prevention of further infections, maintenance of health and provision of treatment to avoid cirrhosis and liver cancer. Additionally, as previous studies in central and eastern Europe show, evidence-based measures to prevent and manage HCV among IDUs, where most current transmission is concentrated, remain limited. Therefore, there is a strong need for intensified advocacy to put HCV higher on both public health and harm reduction agendas.

Hepatitis C virus: the growing challenge

BACKGROUND

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. In industrialized countries, intravenous drug users (IDUs) are the main reservoir of infection. Relatively little information is available on HCV in the developing world.

SOURCES OF DATA

Peer reviewed publications and presentations at major academic meetings.

AREAS OF AGREEMENT

HCV-related cirrhosis and death from hepatocellular carcinoma are likely to rise dramatically in the next three decades. Urgent intervention is required both to minimize the burden of disease in those already infected and to reduce the incidence of new infections, particularly in the IDU population.

AREAS OF CONTROVERSY

Current models of care and commissioning in the UK and other countries do not adequately identify or treat HCV infection in IDUs. Most strategies focus on disease prevention and do not target new infections.

GROWING POINTS

New models of care are currently being developed and validated.

AREAS TIMELY FOR DEVELOPING RESEARCH

The development of new models of HCV replication will transform our understanding and capacity to treat HCV infection.

Clinical trial: a primary-care-based model for the delivery of anti-viral treatment to injecting drug users infected with hepatitis C

BACKGROUND

Injecting drug use is the main risk factor for hepatitis C virus (HCV) infection. Secondary-care-based strategies for the management of HCV do not effectively target this vulnerable population.

AIMS

To evaluate the feasibility, safety and efficacy of a primary-care-based model for the delivery of HCV services including anti-viral therapy to injecting drug users.

METHODS

A partnership between a clinical nurse specialist employed by, and working under the supervision of, a secondary-care-based hepatitis service and drug workers and general practitioners. Three hundred and fifty-three clients attending opiate substitution clinics in primary care were evaluated. Outcomes were: number of new diagnoses of HCV infection, number of clients assessed as suitable for anti-viral treatment, and number of patients treated.

RESULTS

174 HCV antibody positive clients were identified. Of these, 124 were chronically infected with HCV of whom only six had been previously identified. Of 118 new chronically-infected individuals, 86 entered the care pathway, 43 were assessed as suitable for anti-viral treatment and 30 have so far been treated. Outcomes of anti-viral treatment are comparable with those obtained in secondary care settings.

CONCLUSION

A primary-care-based model offers a new paradigm for the treatment of HCV in injecting drug users.

A record-linkage study of the development of hepatocellular carcinoma in persons with hepatitis C infection in Scotland

We investigated trends in first-time hospital admissions and deaths attributable to hepatocellular carcinoma (HCC) in a large population-based cohort of 22 073 individuals diagnosed with hepatitis C viral (HCV) infection through laboratory testing in Scotland in 1991–2006. We identified new cases of HCC through record-linkage to the national inpatient hospital discharge database and deaths registry. A total of 172 persons diagnosed with HCV were admitted to hospital or died with first-time mention of HCC. Hepatocellular carcinoma incidence increased between 1996 and 2006 (average annual change of 6.1, 95% confidence interval (CI): 0.9–11.6%, P=0.021). The adjusted relative risk of HCC was greater for males (hazard ratio=2.7, 95% CI: 1.7–4.2), for those aged 60 years or older (hazard ratio=2.7, 95% CI: 1.9–4.1) compared with 50–59 years, and for those with a previous alcohol-related hospital admission (hazard ratio=2.5, 95% CI: 1.7–3.7). The risk of individuals diagnosed with HCV developing HCC was greatly increased compared with the general Scottish population (standardised incidence ratio=127, 95% CI: 102–156). Owing to the advancing age of the Scottish HCV-diagnosed population, the annual number of HCC cases is projected to increase, with a consequent increasing burden on the public healthcare system.