Operational Handbooks

Ethical issues should be considered from the onset of planning and should involve end-users. The design of screening interventions for specific risk groups should involve risk groups and organizations that might work with these populations, especially groups that face specific access barriers or discrimination. This should help in arriving at user-friendly, acceptable, effective approaches and building demand for services and their use.

Consideration should be given to the extra resources, both human and financial, that will be necessary to prepare for, carry out and monitor screening activities and to accommodate the increased demand for testing of people with presumptive TB and the extra patients who may be identified by screening.

Screening algorithms combine one or several screening tests and one or several diagnostic tests. The accuracy of different screening tests and potential algorithms for different populations and the considerations to be made when selecting algorithms, are discussed in detail in Chapter 3.

Before implementation of a programme, its cost–effectiveness, or cost-benefit – in which costs and benefits are compared in monetary terms – can be modelled from estimates of the predicted number of additional true-positive TB patients detected, the reduction in morbidity, the reduction in the time that a person remains infectious and reductions in transmission, incidence and mortality.

The potential of screening to affect transmission is theoretically highest in congregate settings, such as prisons or overcrowded urban slums, where there is a high rate of transmission and where there is also substantial in-migration and out-migration. In a study in Viet Nam, 3 years of community-wide screening decreased the prevalence of pulmonary TB (26). In principle, the larger the total yield of screening, the larger the potential impact on TB transmission in the community.

The screening procedure itself may be inconvenient and have direct or indirect costs for the individual, which may vary with both the risk group and the screening approach. Harm associated with the results of screening include the unintended negative effects of a correct diagnosis (such as stigmatization or discrimination) and the harm caused by a false-positive or a false-negative screening test or diagnosis.

The benefits include the health, social and economic benefits of early diagnosis and treatment. In principle, the potential benefits are greater for persons who are at highest risk of delayed or missed diagnosis because they meet barriers in obtaining health care (for example, people living in poor communities or remote areas) and especially those at highest risk of unfavourable treatment outcomes when diagnosis is delayed (for example, because their immune system is compromised, such as people living with HIV and children).

The primary goal of TB screening is to reach people who are not reached by the patient-initiated pathway and to detect TB disease early, thereby improving outcomes for individuals and reducing transmission and incidence at population level.

Secondary goals of TB screening are to:

Discrimination based on gender, sexuality, ethnicity or caste or against populations such as sex workers and people who use or inject drugs, can severely limit access to treatment, which may be reinforced by the lack of a framework for protecting human rights. The existing frameworks for protecting human rights and the extent to which they are enforced must be reviewed before systematic screening is implemented.

Before screening is started, it is essential to ensure that people with diagnosed TB have access to affordable, high-quality TB care. This may not be the case for certain vulnerable groups, such as migrants, refugees and homeless people, who may lack identity papers or health insurance. Inclusion criteria for screening, coverage of health insurance (where applicable) and access to health services should be assessed. The system should ensure that people do not pay out of pocket for screening and do not suffer financial hardship as a result of screening.