In 2017, an Irish National Clinical Guideline for Hepatitis Screening was endorsed by the Minister for Health which conditionally recommended offering once-off testing for hepatitis C to people born between 1965 and 1985 (that is, birth cohort testing), subject to the outcome a health technology assessment (HTA). Following publication of the National Clinical Guideline, HIQA commenced work on a HTA which aimed to establish the clinical, cost-effectiveness, and budget impact of introducing birth cohort testing for hepatitis C in Ireland.
HTA of birth cohort testing for hepatitis C
The hepatitis C virus (HCV) is a blood borne virus that predominantly affects the liver. Acute HCV infection is generally defined as the first six months following infection with the virus. Between 55% and 85% of those acutely infected fail to clear the virus and develop chronic HCV infection, the progression of which is slow and unpredictable. Chronic HCV infection is frequently asymptomatic which means that newly diagnosed cases may have been contracted many years previously. If left untreated, over the course of 40 years, between 20% and 40% of people will develop compensated cirrhosis subsequent to the onset of liver fibrosis.
Birth cohort testing involves offering once-off testing for HCV infection to people born during a particular period of time because there is evidence (such as epidemiological trends) of an elevated risk of exposure relative to the overall general population. The Irish birth cohort was identified based on national HCV surveillance and seroprevalence data, which indicated that 72.5% of people with HCV infection were among the population of approximately 1.5 million people born between 1965 and 1985.
This research was carried out in accordance with HIQA’s guidelines for the conduct of HTAs. As part of the HTA, the epidemiology of HCV in Ireland was assessed, the diagnostic accuracy of tests for diagnosing chronic HCV infection was reviewed in addition to the safety and effectiveness of therapies used to treat chronic HCV infection. Systematic reviews of the diagnostic accuracy of laboratory-based tests using dried blood spot samples and the cost-effectiveness of population-based testing strategies for identifying people with undiagnosed chronic HCV infection were also undertaken. An economic model was developed to estimate the cost-effectiveness and budget impact of the potential introduction of birth cohort testing in Ireland. Finally, analyses of the organisational and ethical implications of the proposed introduction of birth cohort testing were undertaken.
The draft HTA was made available for a six-week public consultation period, during which members of the general public and stakeholder organisations had the opportunity to provide feedback on the draft HTA report. Changes were made to the HTA report, as appropriate, following the public consultation.
The HTA was supported by an Expert Advisory Group with representation from the Department of Health, the National Hepatitis C Treatment Programme, the National Virus Reference Laboratory, the National Programme for Pathology, the Health Protection Surveillance Centre, clinicians with specialist expertise in infectious diseases, the National Screening Service, the National Centre for Pharmacoeconomics, the Irish College of General Practitioners, relevant patient advocacy groups and methodological experts.
A birth cohort testing programme to identify and treat those with undiagnosed infection would be a cost-effective use of resources, but would require a significant upfront investment. Over a five-year period, it was estimated that the budget impact of introducing birth cohort testing would be between €44 million and €65 million depending on the type of birth cohort testing programme introduced. Given substantial uncertainty regarding the prevalence of undiagnosed chronic HCV infection in the 1965 to 1985 birth cohort and the logistical challenges posed by a potential birth cohort testing programme, consideration should be given to an initial pilot programme. Further research (such as surveying members of the general public) could also be considered to reduce uncertainty around the likely test uptake rate.