Surgical Mask vs N95 Respirator for Preventing Influenza Among Health Care Workers A Randomized Trial
Surgical Mask vs N95 Respirator for Preventing Influenza Among Health Care Workers A Randomized Trial
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DOI：
10.1001/jama.2009.1466
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发表时间：
2009-11-04
影响因子：
120.7
通讯作者：
Walter, Stephen D.
中科院分区：
文献类型：
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作者：
Loeb, Mark;Dafoe, Nancy;Walter, Stephen D.
关于外科口罩与N95口罩在保护医护人员免受流感侵害方面的有效性的数据很少。鉴于N95口罩在大流行期间可能出现供应短缺，而且许多国家都无法获得，因此了解医用口罩的有效性对公共卫生具有重要意义。目的比较医用口罩与N95口罩对医护人员流感防护的效果。设计、环境和参与者：对安大略省8家三级医院急诊科、医疗单位和儿科单位的446名护士进行非劣效性随机对照试验。干预措施：在2008-2009年流感季节，为患有发热性呼吸道疾病的患者提供护理时，分配经过测试的N95口罩或外科口罩。主要转归指标主要转归指标为聚合酶链反应检测的实验室确诊流感或血凝素滴度升高4倍。与N95呼吸器相比，外科口罩的有效性评估为非劣效性。如果发生率降低（N95呼吸器减去手术组）的95%置信区间（CI）的下限大于-9%，则符合非劣效性标准。结果2008年9月23日至2008年12月8日，478名护士接受了资格评估，446名护士被纳入并随机分配到干预组；225个分配给外科口罩，221个分配给N95呼吸器。外科口罩组有50名护士（23.6%）发生流感感染，N95口罩组有48名护士（22.9%）发生流感感染（绝对风险差为-0.73%；95% CI为-8.8% ~ 7.3%；P= 0.86），下置信限在-9%的非效性限内。结论在安大略省三级医院的护士中，与使用N95口罩相比，使用外科口罩导致实验室确诊流感的发生率不低。试验注册clinicaltrials.gov标识符：NCT00756574 JAMA。2009年;302 (17): 1865 - 1871
Context Data about the effectiveness of the surgical mask compared with the N95 respirator for protecting health care workers against influenza are sparse. Given the likelihood that N95 respirators will be in short supply during a pandemic and not available in many countries, knowing the effectiveness of the surgical mask is of public health importance.Objective To compare the surgical mask with the N95 respirator in protecting health care workers against influenza.Design, Setting, and Participants Noninferiority randomized controlled trial of 446 nurses in emergency departments, medical units, and pediatric units in 8 tertiary care Ontario hospitals.Intervention Assignment to either a fit-tested N95 respirator or a surgical mask when providing care to patients with febrile respiratory illness during the 2008-2009 influenza season.Main Outcome Measures The primary outcome was laboratory-confirmed influenza measured by polymerase chain reaction or a 4-fold rise in hemagglutinin titers. Effectiveness of the surgical mask was assessed as noninferiority of the surgical mask compared with the N95 respirator. The criterion for noninferiority was met if the lower limit of the 95% confidence interval (CI) for the reduction in incidence (N95 respirator minus surgical group) was greater than -9%.Results Between September 23, 2008, and December 8, 2008, 478 nurses were assessed for eligibility and 446 nurses were enrolled and randomly assigned the intervention; 225 were allocated to receive surgical masks and 221 to N95 respirators. Influenza infection occurred in 50 nurses (23.6%) in the surgical mask group and in 48 (22.9%) in the N95 respirator group (absolute risk difference, -0.73%; 95% CI, -8.8% to 7.3%; P=.86), the lower confidence limit being inside the noninferiority limit of -9%.Conclusion Among nurses in Ontario tertiary care hospitals, use of a surgical mask compared with an N95 respirator resulted in noninferior rates of laboratory-confirmed influenza.Trial Registration clinicaltrials.gov Identifier: NCT00756574 JAMA. 2009;302(17):1865-1871