Key steps for assessing and selecting hepatitis testing approaches

Box 19.1 and Fig. 19.1 summarize the key steps for assessing and improving the selection of hepatitis testing approaches, which include setting targets, reviewing the effectiveness of existing testing activities and identifying gaps, and then adjusting programme activities.

Box 19.1

Key steps for assessing and selecting hepatitis testing approaches.

FIG. 19.1

Steps to assess, select and evaluate hepatitis testing approaches.

The final selection and mix of testing approaches with the greatest public health benefit and impact should be based on a situational assessment. This assessment should consider prevalence, unmet need (the estimated number of people who remain undiagnosed), priority populations for the country and the anticipated proportion testing positive, gaps in coverage in geographical areas with undiagnosed HBV and/or HCV infection, the available financial and human resources, and cost–effectiveness. Overall, a mix of hepatitis testing approaches that are focused on populations and/or geographical locations with high HBV or HCV prevalence, and that maximize linkage will have the greatest impact and likely be most cost–effective.

Step 1. Review national and subnational epidemiology

In order to devise successful testing services, it is important for countries to understand which populations and settings have the highest prevalence and incidence of HBV and HCV, the estimated number of people affected in the population, and where the greatest burden of undiagnosed infection exists geographically, and by age, sex and population group.

Although it is difficult to know the exact number of people with chronic hepatitis B or C infection or the number of new infections in a given area, this can be estimated through the analysis of all available epidemiological data from multiple sources, including surveillance, surveys and programmes. As population-based household surveys seldom reach or identify high-risk populations and marginalized vulnerable groups, additional studies may be required.

A summary of the epidemiological situation would include the following, and the information collated can be summarized in Table 19.1.

Table 19.1

A simplified sample template of results of a baseline assessment of testing services.

• Estimates of HBsAg and HCV antibody prevalence in the general and specific high-risk populations
  • An estimate of HBsAg and HCV antibody prevalence in the general population stratified by place (if relevant and available) and age group (for general population to identify which ages are at highest risk), as well as in pregnant women attending ANC from national population-based household surveys and surveillance data among pregnant women;
  • For each high-risk population group identified with a higher prevalence:

    -

    the prevalence of chronic infection in that population group

    -

    an estimation of the proportion of the infected population that belongs to that population group

    -

    an estimation of the size of that population group.

    Once the information on the prevalence has been summarized for the general population and specific groups, an analysis of the situation may guide the selection of groups to target with testing services. Testing population groups with a higher prevalence may have a higher yield but lead to the identification of a lower proportion of those living with infection. Testing the general population (or a defined age or birth cohort) may have a lower yield but leads to the identification of a larger proportion of those living with infection.
• Hepatitis testing uptake, by different populations and testing approaches; and proportion of those tested who are positive, by population, testing approach or facility;
• Number and proportion of people who are aware of their HBV and HCV status Depending on the data available, this may be the proportion of individuals who have ever been tested for HBV or HCV, or of people who were tested in the past 12 months and received their results. These data may be disaggregated by sex, age, geographical region, population type, testing approach and facility.
• Proportion of people who tested positive and who have been enrolled in hepatitis care and treatment services.

Step 2. Set testing (and treatment) coverage targets

For each type of testing service, a target may be set in terms of the number of persons to test and to refer for care and treatment or prevention if they are not infected but are at high ongoing risk. An additional target may include the proportion of persons living with viral hepatitis who are diagnosed. The consolidation of targets of all services considered will lead to an overall target for the number of persons for testing and treatment.

Coordinating testing with treatment scale up. As the primary reason for diagnosing people with chronic hepatitis B and C is so that they can benefit from treatment, it is important to directly link testing and treatment targets. Plans for major scale up of treatment services will not succeed without testing. Similarly, major scale up of testing, which will create a demand for treatment, will have limited benefit without concurrently expanding treatment capacity.

Step 3. Review the effectiveness of existing testing services and identify gaps

Following an epidemiological analysis, an assessment and mapping of current hepatitis testing activities and coverage can determine how well existing services are covering populations in need. This exercise could include the following and the information can be summarized in Table 19.1.

• Mapping of existing services, including location of all current testing settings and sites, uptake and coverage rate (by sex, age and population), and funding source. This may include facility-based testing in ANC, TB, STI clinics as well as in harm reduction, outpatient and inpatient services; outreach testing for key populations, community-based and mobile testing, testing within the workplace or educational institutions; and testing by private health-care providers.
  A detailed situational assessment should also be undertaken with regard to HIV testing services, as in many settings the same populations may be affected, providing the opportunity to integrate hepatitis testing into existing HIV testing delivery models.
• Analysing hepatitis testing services data to see what is being achieved by specific approaches in various sites and locations, in terms of the number and proportion of people tested, new cases diagnosed and enrolled in care;
• Analysing and identifying gaps in current hepatitis testing coverage in relation to burden, by geographical location and population, focusing on areas of highest prevalence or incidence, which are not being reached by available services;
• Assessing the strengths and weaknesses of these testing services, including preferences for testing approaches through key informant interviews with clients and health-care workers;
• Assessing barriers to testing, including social, cultural and geographical factors, psychosocial and behavioural factors, stigma and discrimination, gender and legal factors (including age-of-consent requirements), and structural and health system factors that may impede access;
• Assessing the linkage between hepatitis testing and existing care and treatment programmes, in particular, following a positive diagnosis;
• Assessing laboratory site performance, including the quality of test performance;
• Assessing commodity and human resource needs, their availability, and policies to identify barriers to and opportunities for expanding or shifting the focus of programmes (e.g. availability of rapid test kits or trained lay providers and policies regarding task-sharing), and what education, training and certification are required for those conducting tests. The initial assessment should be followed by an inventory of the resources needed and available for testing services. These include (i) equipment (e.g. testing devices) and supplies (e.g. testing kits); (ii) financial resources; and (iii) human resources.
• Assessing available financial resources for hepatitis testing, including investments by the government and funding partners.

Step 4. Assess costs and cost–effectiveness of different testing approaches

• Assessing costs. Comparing the costs associated with a given testing approach between countries can be challenging. Costs for similar services often differ significantly between countries and by testing approach within a country, due to both general cost differences between countries and to differences in the specific services provided (e.g. referral to a clinic for those testing positive versus enhanced linkage support), cadre of staff employed (e.g. nurses versus community health workers), and the ease of reaching different populations. Direct cost comparisons of different testing approaches are easier to interpret when they use the same costing inputs. A common approach to estimating costs involves identifying costs incurred in the following broad categories: personnel (e.g. staff salaries and allowances); recurrent costs (e.g. test kits and commodities, printed materials, office supplies); and capital expenses, often totalled over their useful life and discounted annually at 3% (e.g. office space, vehicles, equipment). These costs can be added to compute the total expected cost of an intervention per year.
• Estimating cost–effectiveness. Cost–effectiveness analyses compare the costs and health impacts of different interventions to identify those that provide good value for money, and are useful for optimizing the allocation of public health resources. Health outcomes used in cost–effectiveness analyses of hepatitis testing services include: number of people tested; number of hepatitis B or C cases identified; number of infections averted (when linked to vaccination and prevention of MTCT); number of disability-adjusted life-years (DALYs) lost or number of quality-adjusted life-years (QALYs) gained (dependent not only on being diagnosed but linked to treatment).

The health benefits associated with testing are not derived from the test itself, but rather from the treatment and prevention interventions that occur subsequently, including the effectiveness of linkage from testing to treatment. The cost of a programme and its relative cost–effectiveness also depends greatly on the specifics of the programme itself. For example, a programme designed to reach PWID by running mobile camps at various locations can have significantly different costs from providing testing in a fixed location, such as a drug treatment programme. Still, both testing approaches may be necessary to reach this key population. Assessing which testing approaches make the most efficient use of resources requires a detailed understanding of the approaches themselves, including how and to whom they are delivered. Different approaches may be cost–effective for different populations.

Step 5. Monitor, evaluate and adjust programme activities

Ensuring that hepatitis testing programmes are reaching their intended populations and identifying previously undiagnosed positive persons will require continued monitoring and evaluation. For long-term success, the impact of different hepatitis testing approaches on uptake, the proportion that tests positive, costs, and changes in the prevalence of hepatitis B or C in different population groups must be evaluated and measured regularly, and programmes must be adjusted appropriately. Other activities include the following:

• Revisit and revise national targets for and approaches to hepatitis testing so as to better reach those who are undiagnosed, taking into account linkage and enrolment in treatment.
• Develop and follow a national consensus plan for expanding and refocusing hepatitis testing in line with the treatment plan.
• Evaluate implemented programmes through routine programme monitoring, programme-specific evaluations, surveillance and population-based surveys.
• Testing services also require their own monitoring and evaluation framework. In 2016, WHO published a monitoring and evaluation framework for hepatitis B and C ( Monitoring and evaluation for viral hepatitis B and C: recommended indicators and framework. Geneva: WHO, 2016) that proposes ten core indicators (22), and includes the proportion of persons living with HBV or HCV infection diagnosed.