Cost-effectiveness of latent tuberculosis infection testing and treatment for elderly individuals with pulmonary fibrosis lesions in rural communities in China

Elderly individuals with pulmonary fibrosis lesions and latent tuberculosis infection (LTBI) in rural China are high-risk for active tuberculosis (TB), and tuberculosis preventive treatment (TPT) is effective for this group. This study used decision tree-Markov model comparing: targeted CXR_LTBI_6-week H2P2 (6-week rifapentine-isoniazid) and CXR_LTBI_6H (6-month isoniazid) for individuals with chest X-ray (CXR)-detected pulmonary fibrosis lesions and subsequent LTBI positivity, versus non-targeted LTBI_6-week H2P2 and LTBI_6H for elderly LTBI-positive individuals, validated via scenario and sensitivity analyses. Over 5 and 20 year horizons among simulated cohort of 10,000 individuals aged ≥65 years, CXR_LTBI_6-week H₂P₂ served as the only strategy on the cost-effectiveness frontier, with baseline costs of $73,122.83 and $166,058.33, total QALYs of 52,024.52 and 116,650.90, and prevented active TB cases of 40 and 63 respectively. Compared with this strategy, all other strategies were absolutely dominated, presenting fewer prevented active TB cases (1-30), reduced QALYs (0.55-38.39) and elevated total costs ($32,948.71-$1,845,680.24) with CXR_LTBI_6H brought the minimum health loss (0.55 lost QALYs) and cost increment ($32,948.71) among all dominated options. Two scenario analyses regarding the waning long-term protective efficacy of 6-week H2P2 further verified the sustained cost-effectiveness dominance of CXR_LTBI_6-week H2P2. One-way and probabilistic sensitivity analyses consistently confirmed that CXR_LTBI_6-week H2P2 remained the most robust cost-saving strategy regardless of parameter variation and model uncertainty. In conclusion, CXR-guided LTBI TPT is cost-effective among rural elderly Chinese with pulmonary fibrosis lesions, with the 6-week H2P2 regimen as the optimal preventive strategy.