Cost-effectiveness of Xpert® MTB/RIF for diagnosing pulmonary tuberculosis in the United States

SETTING: Conventional approaches to tuberculosis (TB) diagnosis and resistance testing are slow. The Xpert (R) MTB/RIF assay is an emerging molecular diagnostic assay for rapid TB diagnosis, offering results within 2 hours. However, the cost-effectiveness of implementing Xpert in settings with low TB prevalence, such as the United States, is unknown. OBJECTIVE: We evaluated the cost-effectiveness of incorporating Xpert into TB diagnostic algorithms in the United States compared to existing diagnostics. DESIGN: A decision-analysis model compared current TB diagnostic algorithms in the United States to algorithms incorporating Xpert. Primary outcomes were the costs and quality-adjusted life years (QALYs) accrued with each strategy; cost-effectiveness was represented using incremental cost-effectiveness ratios (ICER). RESULTS: Xpert testing of a single sputum sample from TB suspects is expected to result in lower total health care costs per patient (US$2673) compared to diagnostic algorithms using only sputum microscopy and culture (US$2728) and improved health outcomes (6.32 QALYs gained per 1000 TB suspects). Compared to existing molecular assays, implementation of Xpert in the United States would be considered highly cost-effective (ICER US$39992 per QALY gained). CONCLUSION: TB diagnostic algorithms incorporating Xpert in the United States are highly cost-effective.