Efficiency of hepatitis C virus screening strategies in general practice

Who to test and how to test for chronic hepatitis C infection - 2016 WHO testing guidance for low- and middle-income countries

Testing and diagnosis of hepatitis C virus (HCV) infection is the gateway for access to both treatment and prevention services, and crucial for an effective hepatitis epidemic response. In contrast to HIV, a systematic approach to hepatitis C testing has been fragmented and limited to a few countries, and there remains a large burden of undiagnosed cases globally. Key challenges in the current hepatitis testing response, include lack of simple, reliable, and low cost diagnostic tests, laboratory capacity, and testing facilities; inadequate data to guide country-specific hepatitis testing approaches and who to test; stigmatization and social marginalization of some groups with or at risk of viral hepatitis; and lack of international or national guidelines on hepatitis testing for resource-limited settings. New tools to support the hepatitis global response include the 2016 Global Hepatitis Health Sector Strategy which include targets for testing and diagnosis, and World Health Organization (WHO) 2016 hepatitis testing guidelines for adults, adolescents, and children in low- and middle-income countries. The testing guidance complements recent published WHO guidance on the prevention, care and treatment of chronic hepatitis C and hepatitis B infection. These testing guidelines outline the public health approach to strengthening and expanding current testing practices for HCV and HBV and address what serological and virological assays to use, and who to test, as well as interventions to promote linkage to prevention and care after testing. They are intended for use across all age groups and populations. See boxes for key recommendations. Future directions and innovations in viral hepatitis testing include use of point-of-care assays for nucleic acid testing (NAT) and core antigen; validation of dried blood spots specimens with different commercial serological and NAT assays; multiplex and polyvalent platforms for integrated testing of HIV, HBV and HCV; and potential for self-testing.

Cost-effectiveness of screening for hepatitis C virus: a systematic review of economic evaluations

OBJECTIVES

With the developments of near-cures for hepatitis C virus (HCV), who to screen has become a high-priority policy issue in many western countries. Cost-effectiveness of screening programmes should be one consideration when developing policy. The objective of this work is to synthesise the cost-effectiveness of HCV screening programmes.

SETTING

A systematic review was completed. 5 databases were searched until May 2016 (NHSEED, MEDLINE, the HTA Health Technology Assessment Database, EMBASE, EconLit).

PARTICIPANTS

Any study reporting an economic evaluation (any type) of screening compared with opportunistic or no screening for HCV was included. Exclusion criteria were: (1) abstracts or commentaries, (2) economic evaluations of other interventions for HCV, including blood donors screening, diagnosis tests for HCV, screening for concurrent disease or medications for treatment.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data extraction included type of model, target population, perspective, comparators, time horizon, discount rate, clinical inputs, cost inputs and outcome. Quality was evaluated using the Consolidated Health Economic Evaluation Reporting Standards checklist. Data are summarised using narrative synthesis by population.

RESULTS

2305 abstracts were identified with 52 undergoing full-text review. 30 papers met inclusion criteria addressing 7 populations: drug users (n=6), high risk (n=5), pregnant (n=4), prison (n=3), birth cohort (n=8), general population (n=5) and other (n=6). The majority (77%) of the studies were high quality. Drug users, birth cohort and high-risk populations were associated with cost-effectiveness ratios of under £30 000 per quality-adjusted-life-year (QALY). The remaining populations were associated with cost-effectiveness ratios that exceeded £30 000 per QALY.

CONCLUSIONS

Economic evidence for screening populations is robust. If a cost per QALY of £30 000 is considered reasonable value for money, then screening birth cohorts, drug users and high-risk populations are policy options that should be considered.

Cost-Effectiveness of HBV and HCV Screening Strategies--A Systematic Review of Existing Modelling Techniques

Introduction

Studies evaluating the cost-effectiveness of screening for Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) are generally heterogeneous in terms of risk groups, settings, screening intervention, outcomes and the economic modelling framework. It is therefore difficult to compare cost-effectiveness results between studies. This systematic review aims to summarise and critically assess existing economic models for HBV and HCV in order to identify the main methodological differences in modelling approaches.

Methods

A structured search strategy was developed and a systematic review carried out. A critical assessment of the decision-analytic models was carried out according to the guidelines and framework developed for assessment of decision-analytic models in Health Technology Assessment of health care interventions.

Results

The overall approach to analysing the cost-effectiveness of screening strategies was found to be broadly consistent for HBV and HCV. However, modelling parameters and related structure differed between models, producing different results. More recent publications performed better against a performance matrix, evaluating model components and methodology.

Conclusion

When assessing screening strategies for HBV and HCV infection, the focus should be on more recent studies, which applied the latest treatment regimes, test methods and had better and more complete data on which to base their models. In addition to parameter selection and associated assumptions, careful consideration of dynamic versus static modelling is recommended. Future research may want to focus on these methodological issues. In addition, the ability to evaluate screening strategies for multiple infectious diseases, (HCV and HIV at the same time) might prove important for decision makers.

Outcomes of hepatitis C screening programs targeted at risk groups hidden in the general population: a systematic review

BACKGROUND

Effective screening programs are urgently needed to provide undiagnosed hepatitis C virus (HCV)-infected individuals with therapy. This systematic review of characteristics and outcomes of screening programs for HCV focuses on strategies to identify HCV risk groups hidden in the general population.

METHODS

We conducted a comprehensive search of MEDLINE and EMBASE databases for articles published between 1991-2010, including studies that screened the general population using either a newly developed (nonintegrated) screening program or one integrated in existing health care facilities. Look-back studies, prevalence studies, and programs targeting high-risk groups in care (e.g., current drug users) were excluded.

RESULTS

After reviewing 7052 studies, we identified 67 screening programs: 24 nonintegrated; 41 programs integrated in a variety of health care facilities (e.g., general practitioner); and 2 programs with both integrated and nonintegrated strategies. Together, these programs identified approximately 25,700 HCV-infected individuals. In general, higher HCV prevalence was found in programs in countries with intermediate to high HCV prevalence, in psychiatric clinics, and in programs that used a prescreening selection based on HCV risk factors. Only 6 programs used a comparison group for evaluation purposes, and 1 program used theory about effective promotion for screening. Comparison of the programs and their effectiveness was hampered by lack of reported data on program characteristics, clinical follow-up, and type of diagnostic test.

CONCLUSIONS

A prescreening selection based on risk factors can increase the efficiency of screening in low-prevalence populations, and we need programs with comparison groups to evaluate effectiveness. Also, program characteristics such as type of diagnostic test, screening uptake, and clinical outcomes should be reported systematically.

Infection with hepatitis B and C virus in Europe: a systematic review of prevalence and cost-effectiveness of screening

BACKGROUND

Treatment for chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection is improving but not benefiting individuals unaware to be infected. To inform screening policies we assessed (1) the hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus antibody (anti-HCV-Ab) prevalence for 34 European countries; and (2) the cost-effectiveness of screening for chronic HBV and HCV infection.

METHODS

We searched peer-reviewed literature for data on HBsAg and anti-HCV-Ab prevalence and cost-effectiveness of screening of the general population and five subgroups, and used data for people who inject drugs (PWID) and blood donors from two European organizations. Of 1759 and 468 papers found in the prevalence and cost-effectiveness searches respectively, we included 124 and 29 papers after assessing their quality. We used decision rules to calculate weighted prevalence estimates by country.

RESULTS

The HBsAg and anti-HCV-Ab prevalence in the general population ranged from 0.1%-5.6% and 0.4%-5.2% respectively, by country. For PWID, men who have sex with men and migrants, the prevalence of HBsAg and anti-HCV-Ab was higher than the prevalence in the general population in all but 3 countries. There is evidence that HCV screening of PWID and HBsAg screening of pregnant women and migrants is cost-effective.

CONCLUSION

The prevalence of chronic HBV and HCV infection varies widely between European countries. Anti-HCV-Ab screening of PWID and HBsAg screening of pregnant women and migrants have European public health priority. Cost-effectiveness analyses may need to take effect of antiviral treatment on preventing HBV and HCV transmission into account.

Cost effectiveness of hepatitis C-related interventions targeting substance users and other high-risk groups: a systematic review

BACKGROUND AND OBJECTIVE

In developed countries, injection drug users have the highest prevalence and incidence of hepatitis C virus (HCV) infection. Clinicians and policy makers have several options for reducing morbidity and mortality related to HCV infection, including preventing new infections, screening high-risk populations, and optimizing uptake and delivery of antiviral therapy. Cost-effectiveness analyses provide an estimate of the value for money associated with adopting healthcare interventions. Our objective was to determine the cost effectiveness of hepatitis C interventions (prevention, screening, treatment) targeting substance users and other groups with a high proportion of substance users.

METHODS

We conducted a systematic search of MEDLINE, EMBASE, CINAHL, HealthSTAR and EconLit, and the grey literature. Studies were critically appraised using the Drummond and Jefferson, Neumann et al. and Philips et al. checklists. We developed and applied a quality appraisal instrument specific to cost-effectiveness analyses of HCV interventions. In addition, we summarized cost-effectiveness estimates using a single currency and year ($US, year 2009 values).

RESULTS

Twenty-one economic evaluations were included, which addressed prevention (three), screening (ten) and treatment (eight). The quality of the analyses varied greatly. A significant proportion did not incorporate important aspects of HCV natural history, disease costs and antiviral therapy. Incremental cost-effectiveness ratios (ICERs) ranged from dominant (less costly and more effective) to $US603,352 per QALY. However, many ICERs were less than $US100,000 per QALY. Screening and treatment interventions involving pegylated interferon and ribavirin were generally cost effective at the $US100,000 per QALY threshold, with the exception of some subgroups, such as immune compromised patients with genotype 1 infections.

CONCLUSIONS

No clear consensus emerged from the studies demonstrating that prevention, screening or treatment provides better value for money as each approach can be economically attractive in certain subgroups. More high-quality economic evaluations of preventing, identifying and treating HCV infection in substance users are needed.

Identifying former injecting drug users infected with hepatitis C: an evaluation of a general practice-based case-finding intervention

BACKGROUND

In Scotland, a general practice-based case-finding initiative, to diagnose and refer hepatitis C virus (HCV) chronically infected former injecting drug users (IDUs), was evaluated.

METHODS

Testing was offered in eight Glasgow general practices in areas of high deprivation and high HCV and IDU prevalence to attendees aged 30-54 years with a history of IDU. Test uptake and diagnosis rates were compared with those in eight demographically similar control practices.

RESULTS

Of 422 eligible intervention practice attendees, 218 (52%) were offered an HCV test and, of these, 121 (56%) accepted. Poor venous access in 13 individuals prevented testing. Of 105 tested, 70% (74/105) were antibody positive of which 58% (43/74) were RNA positive by PCR. Of 43 chronically infected individuals identified in intervention practices, 22 (51%) had attended specialist care within 30 months of the study, while 9 (21%) had defaulted. In control practices, 8 (22%) of 36 individuals tested were antibody positive. Test uptake and case yield were approximately 3 and 10 times higher in intervention compared with control practices, respectively.

CONCLUSIONS

Targeted case-finding in primary care demonstrated higher test uptake and diagnosis rates; however, to optimize diagnosis and referral of chronically infected individuals, alternative means of testing (e.g. dried blood spots) and retention in specialist care (e.g. outreach services) must be explored.

Evaluation of a general practice based hepatitis C virus screening intervention

BACKGROUND

In 2003 an estimated 37,500 of Scotland's population was chronically infected with HCV; 44% were undiagnosed former injecting drug users (IDU)--a priority group for antiviral therapy.

AIM

To evaluate a hepatitis C virus (HCV) screening intervention.

DESIGN

Outcome measures among two similar General Practice populations in an area of high HCV and drug use prevalence, one of which was exposed to an HCV screening intervention, were compared.

METHODS

Thirty to fifty four year old attendees of the intervention practice were opportunistically offered testing and counselling, where clinically appropriate, (November 2003-April 2004).

OUTCOMES

HCV test uptake, case detection, referral and treatment administration rates.

RESULTS

Of 584 eligible attendees, 421 (72%) were offered and 117 (28%) accepted testing in the intervention practice; no testing was undertaken in the comparison practice. Prevalences of HCV antibody were 13% (15/117), 75% (3/4) and 91% (10/11) among all tested persons, current IDUs and former IDUs respectively. For 4/15 (27%) evidence of binge drinking following the receipt of their positive result, was available. Of the 11 referred to specialist care because they were HCV RNA positive, nine attended at least one appointment. Two received treatment: one had achieved a sustained viral response as of February 2008.

CONCLUSION

While non targeted HCV screening in the general practice setting can detect infected former IDU, the low diagnostic yield among non IDUs limited the effectiveness of the intervention. A more targeted approach for identifying former IDUs is recommended. Additionally, the low uptake of treatment among chronically infected persons four years after diagnosis demonstrates the difficulties in clinically managing such individuals. Strategies, including support for those with a history of problem alcohol use, to improve treatment uptake are required.

Assessment and proposal of a new combination of screening criteria for hepatitis C in France

BACKGROUND

The current French hepatitis C virus infection screening programme is not yet reaching all populations at risk. In order to better identify individuals that would benefit from a screening test, we investigated an expanded combination of personal characteristics as potential screening criteria for this infection.

METHODS

We constructed two multiple-regression models predicting hepatitis C antibody seropositivity using the population sample from the 2004 French national hepatitis C antibody seroprevalence survey (SPS) (n = 14 416): one representing current screening guidelines and another constructed from personal characteristics collected for the SPS. Performance of the two predictive models was statistically compared and we internally validated the better performing model.

RESULTS

The expanded screening criteria model better discriminated seropositive and seronegative individuals [area under the ROC curve (AUC) 0.869 (95% CI 0.861-0.873)] than the current screening guidelines model [AUC 0.821 (95% CI 0.810-0.824)]. This performance difference was statistically significant (P < 0.00001). The expanded criteria model contains the variables age, sex, pre-1992 blood transfusion, intra-venous drug use, receipt of medical welfare for precarious individuals, previous surgeries, illicit nasal drug use, previous hepatitis C screening, tattoo, raised alanine aminotransferase level and birth in a hepatitis C high/moderate-prevalence country.

CONCLUSION

Results indicate that an expanded combination of screening criteria better predicted hepatitis C antibody status and thus individuals needing screening than the current French-screening guidelines. The proposed combination of screening criteria could more effectively target hepatitis C risk-populations in France and could serve as the basis for a decision-making screening tool for the general population.

Screening in liver disease

A disease is suitable for screening if it is common, if the target population can be identified and reached and if both a good screening test and an effective therapy are available. Of the most common liver diseases only viral hepatitis and genetic hemochromatosis partially satisfy these conditions. Hepatitis C is common, the screening test is good and the therapy eliminates the virus in half of the cases, but problems arise in the definition of the target population. In fact generalized population screening is not endorsed by international guidelines, although some recommend screening immigrants from high prevalence countries. Opportunistic screening (case finding) of individuals with classic risk factors, such as transfusion before 1992 and drug addiction, is the most frequently used strategy, but there is disagreement whether prison inmates, individuals with a history of promiscuous or traumatic sex and health care workers should be screened. In a real practice setting the performance of opportunistic screening by general practitioners is low but can be ameliorated by training programs. Screening targeted to segments of the population or mass campaigns are expensive and therefore interventions should be aimed to improve opportunistic screening and the detection skills of general practitioners. Regarding genetic hemochromatosis there is insufficient evidence for population screening, but individual physicians can decide to screen racial groups with a high prevalence of the disease, such as people in early middle age and of northern European origin. In the other cases opportunistic screening of high risk individuals should be performed, with a high level of suspicion in case of unexplained liver disease, diabetes, juvenile artropathy, sexual dysfunction and skin pigmentation.

Decline in HCV testing and compliance with guidelines in patients of Sentinelles general practitioners, 1996–2002

Between 1996 and 2002, the French Sentinelles Network observed a more than 2-fold decline in the annual rate of hepatitis C virus (HCV) screening tests prescribed by general practitioners. During this period it droped from 1080 to 450 per 100,000 inhabitants. The proportion of HCV-positives increased from 9.7% to 12.9% between 1996 and 1998 but declined steadily afterwards, reaching 7% in 2002. The majority of HCV-positive patients were men (57%), 38% were aged 30-39 years and 45% were injecting drug users. Two French guidelines for HCV screening were issued in 1997 and 2001. Of the 3462 patients with a known HCV test result, 27.4% were offered following the 1997 guidelines, among which 23.7% were HCV-positive. Of the same 3462 patients, 36.8% were offered following the extended definition of the risk group in the 2001 guidelines, among which 19.9% were positive. The percentage of subjects tested with no biological sign or clinical symptom and no HCV risk factor varies from 11% to 26% showing that SGPs carry out a targeted screening even if they deviate from the strict recommendations. Of the HCV-positive patients, 14% did not meet any criteria of the guidelines suggesting a lack of sensitivity in the current definition of patients recommended for testing.