guideline decision making. More research is needed to better understand and address this issue.

To accomplish its charge within the 8-week timeframe, the committee held a 4-day meeting that included a day-and-a-half public workshop (Appendix A). Panel discussions focused on the current clinical experience with nH1N1, influenza transmission, clinical and community studies on preventing seasonal influenza or other respiratory virus transmission, risks to healthcare workers in various settings, the efficacy and effectiveness1 of respirators and of medical masks,2 and decision making in infection control. Additionally, 12 individuals provided comments during the public comment session. This report also benefits from the work of prior IOM committees and workshops that have examined issues related to PPE and to pandemic influenza (IOM, 2005a,b, 2006, 2007, 2008a,b).

This report focuses on the scientific and empirical evidence regarding the efficacy of various types of personal respiratory protection technologies as one measure to protect healthcare workers against nH1N1. The committee concludes that an emphasis is needed on implementing a range of strategies across all levels of the hierarchy of controls to minimize risk and decrease the number of healthcare workers and other patients exposed to patients with suspected or confirmed nH1N1. The committee provides the following findings and recommendations and provides additional detail in the report that follows.

Studies on influenza transmission show that airborne (inhalation) transmission is one of the potential routes of transmission. The committee based its decisions on comparisons of the experimental evidence on the efficacy of respirators and medical masks and not on their effectiveness in the clinical setting due to the fact that the availability of data is quite limited on clinical effectiveness. Further, clinical effectiveness requires consideration of numerous implementation factors such as compliance and availability of supply. N95 respirators are documented to filter out 95 to 99 percent of relevant particles and have maximum effectiveness when properly fitted to the face of users through fit testing (Qian


Efficacy is defined as the extent to which a specific intervention produces a beneficial result under ideal circumstances. Effectiveness is defined as a measure of the accuracy or success of an intervention when carried out in an average clinical environment (PDR, 1995).


The committee uses the term medical masks to refer to procedure masks and surgical masks. Because of the wide variety in the types of masks referred to in the articles and presentations reviewed by the committee, the committee uses this term to encompass all types of masks used in healthcare facilities.

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement