Rapid diagnostic test-based algorithms for Chagas disease diagnosis: a cost–utility and budget impact analysis in Colombia

BACKGROUND: Chagas disease remains underdiagnosed in endemic countries due to reliance on centralized laboratory-based algorithms. Rapid diagnostic tests (RDTs) may simplify diagnostic processes and expand access to decentralized testing, but uncertainty remains regarding their performance across heterogeneous settings and long-term economic value. This study evaluated the cost-utility and budget impact of RDT-based diagnostic strategies in Colombia. METHODS: A cost-utility analysis was conducted from the Colombian health system perspective using a hybrid decision tree-Markov model. Three diagnostic strategies were compared: serial RDT with ELISA resolution, hybrid RDT-ELISA and the conventional ELISA algorithm with indirect immunofluorescence assay resolution. Lifetime costs and quality-adjusted life years (QALYs) were estimated. The model incorporated loss to follow-up between steps. Scenario analyses explored correlated test performance and earlier diagnosis among women of reproductive age. A 5-year budget impact analysis was conducted. RESULTS: Lifetime costs were US$319.27, US$266.03 and US$252.74, with corresponding QALYs of 12.30, 12.34 and 12.35 for the conventional, hybrid and serial RDT strategies, respectively. Both RDT-based strategies were economically dominant. CONCLUSIONS: RDT-based algorithms may improve access to diagnosis and reduce program costs. Improving completion of the diagnostic process may be a key driver of effectiveness and economic value.