OBJECTIVE: To determine the cost-effectiveness of the QuantiFERON (QFT) test versus the tuberculin skin test (TST) in diagnosing latent tuberculosis infection (LTBI) in immunocompetent children under 15 years of age who are in contact with active tuberculosis (TB) patients in the context of the Colombian healthcare system. DESIGN: Health economic evaluation. Decision tree over a horizon of <
1 year. SETTING: From the perspective of the Colombian healthcare system, the direct healthcare costs related to tests were considered, and diagnostic performance was used as a measure of effectiveness. The currency was the US dollar (US for the year 2022, with a cost-effectiveness threshold of US666. PARTICIPANTS: A simulated hypothetical cohort of 2000 immunocompetent children under 15 years of age who are in contact with active TB patients and were vaccinated with BCG at birth. INTERVENTIONS: QFT test and TST to detect LTBI. PRIMARY OUTCOME MEASURE: The incremental cost-effectiveness ratio (ICER) was estimated, and univariate deterministic and probabilistic sensitivity analyses were conducted using 5000 simulations. RESULTS: QFT was found to be cost-effective with an ICER of US05 for each correctly diagnosed case. In the one-way deterministic sensitivity analysis, QFT remained cost-effective across nearly all proposed scenarios
however, the QFT was considered 'potentially cost-effective' when TST specificity reached its highest value. The ICER was unaffected by variations in LTBI prevalence. In the probabilistic sensitivity analysis, QFT was cost-effective in 85.06% of the simulated scenarios, while TST was dominant in 11.8%. CONCLUSIONS: This study provides evidence of the cost-effectiveness of QFT compared with TST in diagnosing LTBI among immunocompetent children under 15 years who have been in contact with active TB patients in the Colombian context.