Effectiveness and costeffectiveness of screening immigrants schemes for tuberculosis (TB) on arrival from high TB endemic countries to low TB prevalent countries

Background: Immigrants to developed countries are a major source of TB. Therefore amongst strategies adopted for TB control in developed countries include; 1) Screening immigrants at ports of entry referred to as "Port of Arrival Screening" (PoA) and 2) Passive screening (PS) for TB which means screening immigrants through general practices, hospitals, chest-clinics and emergency departments. Evidence of the effectiveness and cost effectiveness of these strategies is not consistent. Objective: Evaluate efficiency of active PoA TB screening for immigrants from TB endemic-regions compared with Passive Screening of immigrant-populations from TB endemic-regions. Methods: Major electronic-databases and reference lists of relevant studies were searched. Experts of immigrants' TB screening were contacted for additional studies published or unpublished. Systematic search of major databases identified only retrospective cohort-studies. Their qualities were assessed using Scottish Intercollegiate Guidelines Network (SIGN) methodological checklist for comparative cohort-studies. Results: Systematic electronic searches identified 1443 citations. Of these 74 studies were retrieved for evaluation against the review's inclusion/exclusion criteria (see study inclusion/exclusion criteria). Four studies met the inclusion criteria (figure 2) which were low in the evidence hierarchy of primary effectiveness studies and had heterogeneities between them. Thus descriptive data-synthesis was performed. Proportionately PoA screening had the lowest percentage of receipt of tuberculin skin test (TST) and the highest percentage of non-attendance for TST reading (table 2). Active PoA screening reduced infectiousness by 34% compared to 30% by passive screening and new entrants screened at PoA were 80% less likely to be hospitalised Odds ratio (OR) = 0.2 (95% confidence interval (CI) 0.1-0.2). Economic analysis: One cost effectiveness analysis was found that compared the costs of; active PoA screening, general practice screening and homeless screening groups. The cost of detecting a case of TB were; 1.26 pound, 13.17and pound 96.36 pound for PS, homeless screening and active PoA screening respectively. The cost of preventing a case of TB were; 6.32 pound, 23.00 pound and 10.00 pound for PS, homeless screening and PoA screening respectively, showing there is little difference between the different strategies. Conclussion: Active PoA screening is worth doing with significant benefits including early identification of risk groups with possible timely treatment/chemoprophylaxis intervention, prevention of transmission by significantly reducing infectiousness with subsequent avoidance of hospitalisation in active PoA screening group.