The committee reviewed and considered a broad array of information prior to making recommendations on the development of reusable facemasks for use during an influenza pandemic. Sources of information include primary scientific literature, books, and scientific reviews; presentations from researchers and representatives from federal agencies and the manufacturing industry; U.S. patents for respirators; news articles; standards for the testing methods of respiratory protection devices; and other relevant government guidelines. Compilation of this background material commenced in January 2006, the month the study was commissioned by the Department of Health and Human Services (DHHS), and ended in March 2006, shortly before the report was released to external review.
The committee and National Academies staff used an extensive online bibliographic search to compile a reference database of literature relevant to the topics of respiratory protection and pandemic influenza. This thorough review of the literature used relevant databases that included Medline, EMBASE (Exerpta Medica), NTIS (National Technical Information Service), BIOSIS, CINAHL (Cumulative Index to Nursing & Allied Health Literature), and Lexis-Nexis.
The literature review involved five stages. The first stage consisted of
the IOM staff conducting general bibliographic searches on topics related to influenza and respiratory protection and compiling a list of references from presentations given at the committee’s first meeting and other conferences on respiratory protection and pandemic influenza. These references were categorized and annotated by the staff and then used as a source for a set of key indexing terms.
The second stage was an initial, simple search that used a basic combination of keywords to identify any articles that mentioned or discussed the N95 respirator: “N95” was combined with the terms “respirator” or “respirators” or “mask” or “facepiece” or “filter,” etc. This simple search strategy was used on the Medline, EMBASE, NTIS, BIOSIS, CINAHL, and Lexis-Nexis databases.
The third stage was to perform a second, and much more sophisticated, series of searches on the Medline database, which resulted in several sets of entries. A Medline search was first performed for articles using keywords that fell under a “mask terminology set” category. This category included “masks,” “face mask,” “surgical mask,” “respiratory protective devices,” “personal protective device,” “personal protective equipment,” and “personal protective gear” as search terms. Another search set for “prevention and control of diseases” was created by screening articles for use of terms such as “disease outbreak,” “cross infection,” “disease transmission,” “transmission,” and “prevention and control.” The mask terminology set was combined with the set on prevention and control of diseases. The common results from these two sets formed the basis for further refinement of the reference list.
Accordingly, the results from this combination search were then cross-referenced with more specific terms such as “guideline adherence,” “safety,” “equipment contamination,” “filtration” or “filter media,” “equipment design,” “particle size,” “permeability,” “health education,” “community health services,” and materials such as “wool,” “gauze,” “cotton,” “fabric,” etc. Search results could be further refined by selecting a specific publication date range and English as the publication language.
The fourth stage was to use the Medline searches as a template for searches on other databases, such as EMBASE, NTIS, BIOSIS, and CINAHL. The results of searches from the various databases were exported separately into ProCite, resulting in a total of 1,650 entries.
The fifth and final stage of the search involved a screen of the nearly 1,700 titles and abstracts to determine the most relevant articles for the committee’s use, resulting in a final count of approximately 320 entries.
In addition to the staff-provided articles, the committee was provided articles for their consideration from several outside parties. Staff distributed these articles to the committee, and they are also listed in the committee’s public access file.
MANUFACTURERS OF CERTIFIED MEDICAL MASKS AND N95 RESPIRATORS
In order to thoroughly address the issues related to developing reusable facemasks and respirators for use during an influenza pandemic, the committee thought it was crucial to obtain input from industry. Thus, the committee solicited input from manufacturers of FDA-approved medical masks and NIOSH-approved N95 respirators.
A list of specific questions was posed to manufacturers in the form of a letter, with the expectation that the answers would help guide the committee’s discussion and facilitate the formation of recommendations. The full list of questions is displayed in Box A-1.
The list of manufacturers of NIOSH-certified N95 respirators and FDA–market-approved medical masks was compiled using the database available on the NIOSH and FDA websites. This search resulted in the names of 130 companies that produce medical masks and 67 manufacturers of N95 respirators. These lists were further culled down to a total of 70 companies after redundancies were eliminated (Box A-2).
Nine companies responded to the committee’s letter: 3M, Aeareo, Alpha Pro-Tech, Bacou-Dalloz, Cardinal Health, Kimberly Clark, Lab Safety Supply, Moldex-Metric, and Triosyn.
The committee thought that representatives of the poultry industry might want to provide input to the committee because their employers are also concerned with respiratory protection. Representatives of the poultry industry community were therefore invited both to attend the March workshop and to participate in the open testimony in order to provide relevant information to the committee. The groups contacted were the National Chicken Council, Pilgrim’s Pride, Purdue, Tyson’s, and the chicken trade journal, WATT Poultry Industries. None of the groups participated in the workshop.
Questions Posed to Manufacturers in Advance of the Second Committee Meeting
The committee held two meetings over the course of the study to address the study charge, review the data collected, and develop the report. Both of those meetings included public sessions: January 23–24, 2006, and March 6–8, 2006. The agendas for both meetings are included at the end of this appendix.
The first meeting (Box A-3) included a session that covered the sponsor’s presentation of the statement of task, a panel discussion with
government agencies, and talks from manufacturers of respiratory protection devices.
The committee held a public workshop (Box A-4) on March 6–7, 2006. During that workshop, the committee heard from 22 speakers who had expertise in influenza and respiratory protection, the production and design of both medical masks and respirators, and the reusability of medical masks and respirators.
In preparation for the second workshop, the committee developed a set of tentative underlying assumptions that served as talking points during the second meeting. These tentative underlying assumptions were grouped into four broad categories that roughly paralleled the order of topics planned for discussion in the workshop: influenza transmission, respirators, medical masks, and reuse of respirators and medical masks. These underlying assumptions facilitated the committee’s creation of a set of prudent and practical recommendations in response to its two-part statement of task.
List of Manufacturers Solicited for Input
Agenda: Committee Meeting Number 1
Panel Discussion with Government Agencies
Panel Discussion with Manufacturers
Agenda: Committee Meeting Number 2 and Public Workshop
March 6, 2005
SESSION 1: Overview of Mask and Respiratory Protection
Panel 1: The Users’ Perspectives on Respiratory Protection
SESSION 2: Surgical Mask Production and Design
SESSION 3: N95 Respirator Production and Design
Panel 2: Respirator Production and Design
March 7, 2006