Muniyandi Malaisamy, Nagarajan Karikalan, Mathiyazhagan Kavi, Tyagi Kirti, Rajsekar Kavitha, Padmapriyadarsini Chandrasekaran
Indian Council of Medical Research-National Institute for Research in Tuberculosis, Chennai, India.
Department of Health Research, Ministry of Health and Family Welfare, New Delhi, India.
Int Health. 2025 May 1;17(3):259-269. doi: 10.1093/inthealth/ihae048.
Latent tuberculosis infection (LTBI) remains a significant challenge, as there is no gold standard diagnostic test. Current methods used for identifying LTBI are the interferon-γ release assay (IGRA), which is based on a blood test, and the tuberculin skin test (TST), which has low sensitivity. Both these tests are inadequate, primarily because they have limitations with the low bacterial burden characteristic of LTBI. This highlights the need for the development and adoption of more specific and accurate diagnostic tests to effectively identify LTBI. Herein we estimate the cost-effectiveness of the Cy-Tb test as compared with the TST for LTBI diagnosis.
An economic modelling study was conducted from a health system perspective using decision tree analysis, which is most widely used for cost-effectiveness analysis using transition probabilities. Our goal was to estimate the incremental cost and number of TB cases prevented from LTBI using the Cy-Tb diagnostic test along with TB preventive therapy (TPT). Secondary data such as demographic characteristics, treatment outcome, diagnostic test results and cost data for the TST and Cy-Tb tests were collected from the published literature. The incremental cost-effectiveness ratio was calculated for the Cy-Tb test as compared with the TST. The uncertainty in the model was evaluated using one-way sensitivity analysis and probability sensitivity analysis.
The study findings indicate that for diagnosing an additional LTBI case with the Cy-Tb test and to prevent a TB case by providing TPT prophylaxis, an additional cost of 18 658 Indian rupees (US$223.5) is required. The probabilistic sensitivity analysis indicated that using the Cy-Tb test for diagnosing LTBI was cost-effective as compared with TST testing. If the cost of the Cy-Tb test is reduced, it becomes a cost-saving strategy.
The Cy-Tb test for diagnosing LTBI is cost-effective at the current price, and price negotiations could further change it into a cost-saving strategy. This finding emphasizes the need for healthcare providers and policymakers to consider implementing the Cy-Tb test to maximize economic benefits. Bulk procurements can also be considered to further reduce costs and increase savings.
由于缺乏金标准诊断测试，潜伏性结核感染（LTBI）仍然是一项重大挑战。目前用于识别LTBI的方法是基于血液检测的干扰素-γ释放试验（IGRA）和敏感性较低的结核菌素皮肤试验（TST）。这两种测试都存在不足，主要是因为它们在LTBI细菌载量较低的特征方面存在局限性。这凸显了开发和采用更特异、准确的诊断测试以有效识别LTBI的必要性。在此，我们评估了Cy-Tb测试与TST用于LTBI诊断的成本效益。
从卫生系统角度进行了一项经济建模研究，采用决策树分析，这是使用转移概率进行成本效益分析最广泛使用的方法。我们的目标是估计使用Cy-Tb诊断测试以及结核病预防性治疗（TPT）预防LTBI导致的结核病病例的增量成本和数量。从已发表的文献中收集了诸如人口统计学特征、治疗结果、诊断测试结果以及TST和Cy-Tb测试的成本数据等二级数据。计算了Cy-Tb测试与TST相比的增量成本效益比。使用单向敏感性分析和概率敏感性分析评估模型中的不确定性。
研究结果表明，使用Cy-Tb测试诊断另外一例LTBI病例并通过提供TPT预防措施来预防一例结核病病例，需要额外花费18658印度卢比（223.5美元）。概率敏感性分析表明，与TST测试相比，使用Cy-Tb测试诊断LTBI具有成本效益。如果Cy-Tb测试的成本降低，它将成为一种节省成本的策略。
以当前价格，用于诊断LTBI的Cy-Tb测试具有成本效益，价格谈判可能会使其进一步转变为节省成本的策略。这一发现强调了医疗服务提供者和政策制定者需要考虑实施Cy-Tb测试以实现经济效益最大化。也可以考虑批量采购以进一步降低成本并增加节省。
