<b>TABLE 3. Factors associated with TB</b>

<b>Retrospective analysis of tuberculosis screening in vulnerable populations in Barcelona (2018–2024).</b><b> </b>In high-income countries, tuberculosis (TB) has a major impact on vulnerable populations. Active case-finding strategies target these populations, allowing the identification of TB in asymptomatic individuals and improving the local epidemiological situation. Objectives: To evaluate the impact of ACF and to define the factors associated with a higher probability of presenting TB in vulnerable populations. Methods. Observational, descriptive, and retrospective study. We analyzed the results of ACF studies performed in vulnerable populations (social service users, drug users and recent migrants from high-TB areas) in Barcelona between 2018 and 2024. Results. 10149 records of vulnerable individuals were studied. 73 people were diagnosed and treated for TB (0.72%). There was microbiological confirmation in 47 (64.4%). Resistance to isoniazid was detected in 2 cases (2.7%) and multi-drug resistance in 6 (8.2%). Treatment was completed in 64 (87.7%). Risk factors associated with TB were (Prevalence Ratio=PR; 95% confidence interval:CI): age less than 30 years (PR=4.1, CI:1.6-10.5), homelessness (PR=4.0;CI:2.6-9.2), migrant (PR=6.2; CI:2.6-9.2), with residence less than 5 years (PR=4.4 ;CI:2.1-9.2). Conclusion.ACF targeting vulnerable populations allows the early detection of TB. Priority should be given to the study of groups at higher risk of developing TB, such as homeless people and recent migrants. Keywords: Tuberculosis; active case-finding; vulnerable population