Cost-effectiveness of latent tuberculosis infection testing and preventive treatment among TB contacts in China: a Markov model

This study evaluates the costs and cost-effectiveness of latent tuberculosis infection (LTBI) testing and preventive treatment (TPT) strategies among close contacts of active tuberculosis (ATB) patients in China using a Markov model, with the aim of informing the optimization of national TPT strategies. A Markov model was developed to evaluate the cost-effectiveness of LTBI testing with purified protein derivative (PPD), Mycobacterium TB antigen-based skin test (TBST), or interferon-gamma release assay (IGRA), each followed by either a 4-week thrice-weekly rifapentine plus isoniazid regimen (1 H3P3) or a 3-month twice-weekly rifapentine plus isoniazid regimen (3 H2P2), in a hypothetical cohort of 10,000 close contacts of ATB patients with a mean age of 38 years. The primary outcome was the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life years (QALY) gained, and strategies were judged against China’s 2024 per-capita GDP–based willingness-to-pay (WTP) threshold (¥95,754 per QALY). In the base-case analysis, LTBI testing with TBST or IGRA followed by treatment with 1 H3P3 was the dominant strategy. Specifically, LTBI testing with TBST followed by 1 H3P3 resulted in a cost of ¥8,367.79 (95% UI: ¥-76549.62, ¥79,656.24) per QALY gained, which is below WTP threshold. Sensitivity analysis indicated that LTBI prevalence and utility values assigned to cure ATB or self-healing in ATB substantially influenced incremental cost-effectiveness ratios. LTBI testing with TBST followed by treatment with 1 H3P3 is a cost-effective strategy and may represent an optimum for tuberculosis control among close contacts of ATB patients in China.