Standard diagnostics with and without urine-based lipoarabinomannan testing for tuberculosis disease in HIV-infected patients in a high-burden setting–A cost-effectiveness analysis

Abstract

Background Recent clinical findings reported the reduced mortality associated with treatment guided by sputum-based molecular test with urine-based lipoarabinomannan (LAM) assay for tuberculosis (TB) disease in HIV-infected individuals. We aimed to evaluate the cost-effectiveness of sputum-based Xpert tests with and without urine-based LAM assays among HIV-infected individuals with signs and symptoms of TB disease (TBD) from the perspective of South African healthcare providers. Methods A one-year decision-analytic model was constructed to simulate TB-related outcomes of 7 strategies: Sputum smear microscope (SSM), Xpert, Xpert Ultra, Xpert with AlereLAM, Xpert Ultra with AlereLAM, Xpert with FujiLAM, and Xpert Ultra with FujiLAM, in a hypothetical cohort of adult HIV-infected individuals with signs and symptoms of TB. The model outcomes were TB-related direct medical cost, mortality, early treatment, disability-adjusted life-years (DALYs) and incremental cost per DALY averted (ICER). The model inputs were retrieved from literature and public data. Base-case analysis and sensitivity analysis were conducted. Results In the base-case analysis, the Xpert Ultra with FujiLAM strategy showed the highest incidence of early treatment (267.7 per 1000 tested) and lowest mortality (29.0 per 1000 tested), with ICER = 676.9 USD/DALY averted. Probabilistic sensitivity analysis of 10,000 Monte Carlo simulations showed the cost-effective probability of Xpert Ultra with FujiLAM was the highest of all 7 strategies at the willingness-to-pay (WTP) threshold >202USD/DALY averted. Conclusion Standard sputum-based TB diagnostic Xpert Ultra with urine-based FujiLAM for TBD testing in HIV-infected individuals appears to be the preferred cost-effective strategy from the perspective of the health service provider of South Africa.