de Perio Marie A, Tsevat Joel, Roselle Gary A, Kralovic Stephen M, Eckman Mark H
Division of Infectious Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Box 670560, Cincinnati, OH 45267, USA.
Arch Intern Med. 2009 Jan 26;169(2):179-87. doi: 10.1001/archinternmed.2008.524.
Interferon gamma release assays (IGRAs) offer alternatives to tuberculin skin tests (TSTs) for diagnosing latent tuberculosis infection (LTBI). Unlike TSTs, IGRAs require only a single patient visit and are not affected by prior BCG vaccination, providing greater specificity. Of 2 Food and Drug Administration-approved IGRAs, the newer QuantiFERON-TB Gold in Tube test (QFT-GIT) requires less manual processing time than the QuantiFERON-TB Gold test (QFT-G). We compared the cost-effectiveness of the QFT-G, QFT-GIT, and TST for detecting LTBI in new health care workers (HCWs).
A Markov state-transition decision analytic model using the societal perspective and lifetime horizon was constructed to compare costs and quality-adjusted life-years (QALYs) associated with the 3 strategies for hypothetical 35-year-old HCWs with or without prior BCG vaccination. Direct and indirect costs and probabilities were based on manufacturer data, national Veterans Health Administration records, and the published literature. Future costs and QALYs were discounted at 3% per year.
Both IGRAs were more effective and less costly than the TST, whether or not the HCW had been vaccinated with BCG previously. The incremental cost-effectiveness ratio of the QFT-G compared with the QFT-GIT was $14,092/QALY for non-BCG-vaccinated HCWs and $103,047/QALY for BCG-vaccinated HCWs. There was no prevalence of LTBI at which the TST became the most effective or least costly strategy. If the sensitivity of the QFT-GIT exceeds that of the QFT-G, then the QFT-GIT is the most effective and least costly strategy.
Use of the QFT-G and QFT-GIT leads to superior clinical outcomes and lower costs than the TST and should be considered in screening non-BCG-vaccinated and BCG-vaccinated new HCWs for LTBI.
干扰素γ释放试验（IGRAs）为诊断潜伏性结核感染（LTBI）提供了结核菌素皮肤试验（TSTs）的替代方法。与TSTs不同，IGRAs仅需患者就诊一次，且不受既往卡介苗接种的影响，具有更高的特异性。在两种经美国食品药品监督管理局批准的IGRAs中，较新的全血干扰素γ释放试验（QFT-GIT）相比全血干扰素γ释放试验（QFT-G）所需的手工操作时间更少。我们比较了QFT-G、QFT-GIT和TST在检测新入职医护人员（HCWs）LTBI方面的成本效益。
构建了一个采用社会视角和终身视角的马尔可夫状态转换决策分析模型，以比较35岁、有无既往卡介苗接种的假设性新入职医护人员采用这三种策略的成本和质量调整生命年（QALYs）。直接和间接成本及概率基于制造商数据、国家退伍军人健康管理局记录和已发表的文献。未来成本和QALYs按每年3%进行贴现。
无论医护人员之前是否接种过卡介苗，两种IGRAs均比TST更有效且成本更低。对于未接种卡介苗的医护人员，QFT-G与QFT-GIT相比的增量成本效益比为每QALY 14,092美元；对于接种卡介苗的医护人员，该比值为每QALY 103,047美元。不存在使TST成为最有效或成本最低策略的LTBI患病率。如果QFT-GIT的敏感性超过QFT-G，则QFT-GIT是最有效且成本最低的策略。
与TST相比，使用QFT-G和QFT-GIT可带来更好的临床结果和更低的成本，在筛查未接种卡介苗和接种卡介苗的新入职医护人员的LTBI时应予以考虑。
