Adal K A, Anglim A M, Palumbo C L, Titus M G, Coyner B J, Farr B M
University of Virginia Health Sciences Center, Charlottesville 22908.
N Engl J Med. 1994 Jul 21;331(3):169-73. doi: 10.1056/NEJM199407213310306.
After outbreaks of multidrug-resistant tuberculosis, the Centers for Disease Control and Prevention proposed the use of respirators with high-efficiency particulate air filters (HEPA respirators) as part of isolation precautions against tuberculosis, along with a respiratory-protection program for health care workers that includes medical evaluation, training, and tests of the fit of the respirators. Each HEPA respirator costs between $7.51 and $9.08, about 10 times the cost of respirators currently used.
We conducted a cost-effectiveness analysis using data from the University of Virginia Hospital on exposure to patients with tuberculosis and rates at which the purified-protein-derivative (PPD) skin test became positive in hospital workers. The costs of a respiratory-protection program were based on those of an existing program for workers dealing with hazardous substances.
During 1992, 11 patients with documented tuberculosis were admitted to our hospital. Eight of 3852 workers (0.2 percent) had PPD tests that became positive. Five of these conversions were believed to be due to the booster phenomenon; one followed unprotected exposure to a patient not yet in isolation; the other two occurred in workers who had never entered a tuberculosis isolation room. These data suggest that it will take more than one year for the use of HEPA respirators to prevent a single conversion of the PPD test. Assuming that one conversion is prevented per year, however, it would take 41 years at out hospital to prevent one case of occupationally acquired tuberculosis, at a cost of $1.3 million to $18.5 million.
Given the effectiveness of currently recommended measures to prevent nosocomial transmission of tuberculosis, the addition of HEPA respirators would offer negligible protective efficacy at great cost.
在耐多药结核病暴发后，疾病控制与预防中心提议使用带有高效空气微粒过滤器的呼吸器（高效空气过滤器呼吸器）作为结核病隔离预防措施的一部分，同时为医护人员制定一项呼吸防护计划，该计划包括医学评估、培训以及呼吸器适配性测试。每个高效空气过滤器呼吸器的成本在7.51美元至9.08美元之间，约为目前使用的呼吸器成本的10倍。
我们利用弗吉尼亚大学医院关于接触结核病患者的数据以及医院工作人员中纯化蛋白衍生物（PPD）皮肤试验呈阳性的发生率进行了成本效益分析。呼吸防护计划的成本基于现有的针对处理有害物质的工作人员的计划。
1992年期间，我院收治了11例确诊为结核病的患者。3852名工作人员中有8人（0.2%）的PPD试验呈阳性。其中5例转变被认为是由于加强反应现象；1例是在未采取防护措施接触尚未隔离的患者之后；另外2例发生在从未进入过结核病隔离病房的工作人员身上。这些数据表明，使用高效空气过滤器呼吸器预防PPD试验的单次转变需要一年多时间。然而，假设每年能预防一次转变，在我院预防一例职业性获得性结核病需要41年，成本为130万美元至1850万美元。
鉴于目前推荐的预防医院内结核病传播措施的有效性，增加高效空气过滤器呼吸器将以高昂成本提供微不足道的防护效果。
