FeedbackSystematic screening for TB fulfils the classic screening criteria (8). The following key principles are to be considered in planning a TB screening initiative:
- Principle 1: TB screening should always be done with the intention to follow up with appropriate medical care and ideally implemented where high-quality TB diagnostic and treatment services are available. If a community lacks access to appropriate follow-up care but would benefit from TB screening, this should be an impetus for investment by national TB programmes in TB diagnosis and treatment services, in order to complement TB screening.
- Principle 2: Screening should reach the people at greatest risk of developing TB disease, including high-risk groups and communities with a high prevalence of TB. Prioritization of risk groups for screening should be based on an assessment for each group of the potential benefits and harm, the feasibility and acceptability of the screening approach, the number needed to screen (NNS) and the cost–effectiveness of screening. The benefits and harm of TB screening in different groups and populations need to be carefully assessed to maximize the common good while minimizing harm to individuals. TB threatens the health not only of an affected individual but also of their communities and the broader population.
- Principle 3: TB screening should follow established ethical principles for screening for infectious diseases, including obtaining voluntary informed consent before proceeding with screening individuals and observing human rights, and be designed to minimize the risks of discomfort, pain, stigmatization and discrimination. Informed consent is a basic right and an important means of respecting an individual’s autonomy.
- Principle 4: The choice of algorithm for screening and diagnosis is based on an assessment of the accuracy of the algorithm for each risk group, as well as the availability, feasibility and cost of the screening tests. After a positive screening test result, the diagnosis of TB should be confirmed before TB treatment is started.
- Principle 5: TB screening should be synergized with the delivery of other health and social services. Synergies are best identified during the development and implementation of screening approaches for different target populations, which may have particular patterns of use of health and social services.
- Principle 6: A screening strategy is expected to maximize coverage and frequency of screening to achieve its aims. Regular monitoring is necessary to inform any re-prioritization of risk groups, resource use, adaptation of screening approaches and discontinuation of screening. This includes the assessment of risk of false-positive diagnoses resulting from screening.