INTENT AND GOALS OF THE STUDY
Public Law 108-183, the Veterans Benefits Act of 2003, directed the Secretary of Veterans Affairs to contract with the National Academy of Sciences (NAS) to address several questions regarding the appropriate disposition of the Air Force Health Study (AFHS). The AFHS is an epidemiologic study of U.S. Air Force (USAF) personnel who were responsible for conducting aerial spray missions of herbicides during the Vietnam era—called Ranch Hands because the spray program was designated Operation Ranch Hand—and a matched cohort of comparison subjects who performed similar duties in Southeast Asia during the same time period but who were not involved with herbicide spraying. The study’s first of six cycles of physical examinations were conducted in 1982 on 1,046 Ranch Hands and 1,223 comparison subjects (Michalek, 2005).
Section 602(c) of Pub. L. 108-183 charged the NAS to evaluate the following:
(1) The scientific merit of retaining and maintaining the medical records, other study data, and laboratory specimens collected in the course of the Air Force Health Study after the currently scheduled termination date of the study in 2006.
(2) Whether or not any obstacles exist to retaining and maintaining the medical records, other study data, and laboratory specimens referred to in paragraph (1), including privacy concerns.
(3) The advisability of providing independent oversight of the medical records, other study data, and laboratory specimens referred to in paragraph (1), and of any further study of such records, data, and specimens, and, if so, the mechanism for providing such oversight.
(4) The advisability of extending the Air Force Health Study, including the potential value and relevance of extending the study, the potential cost of extending the study, and the federal or nonfederal entity best suited to continue the study if extended.
(5) The advisability of making the laboratory specimens of the Air Force Health Study available for independent research, including the potential value and relevance of such research, and the potential cost of such research.
In response to a request by the Secretary of Veterans Affairs, the Institute of Medicine (IOM) of the National Academies constituted the Committee on the Disposition of the Air Force Health Study to tackle these issues.
INFORMATION GATHERING BY THE COMMITTEE
The committee conducted four meetings. During the first meeting, the committee received its charge from Dr. Mark Brown, the director of the Environmental Agents Service of the Department of Veterans Affairs (VA). The committee was also briefed on the study design, protocol, and results of the AFHS by the study’s then principal investigator, Dr. Joel E. Michalek. The second and third meetings included workshop sessions with presentations from experts in the conduct of longitudinal epidemiologic studies and the management and dissemination of epidemiologic data and biospecimens. Representatives of veterans service organizations also presented information for the consideration of the committee. Appendix A lists the workshop speakers and presentation topics. The final meeting was a closed session where committee members concluded their deliberations and finalized their findings, conclusions, and recommendations.
In addition to the meetings and workshops, the committee engaged in an extensive effort to collect other information on topics relevant to its charge. As part of this effort, four members of the committee—Drs. Blazer, Hankinson, Kalman, and Richardson—conducted a site visit to the AFHS research facility at Brooks City-Base, San Antonio, Texas, on May 27, 2005. Accompanying them were IOM study staff and Mr. Victor Pontes, a consultant to the committee on issues related to SAS datasets.1 The intent of the visit was to evaluate the state of the documentation of the study’s data assets, examine how they were stored, and assess the ease of access to them. Working groups were established to focus on the electronically stored data and the specimens. Their findings are summarized in the committee’s interim letter report (IOM, 2005a).
The committee’s information gathering was greatly aided by AFHS staff members, who were helpful in answering the committee’s many questions. The committee thanks them for their cooperation.
THE COMMITTEE’S INTERIM LETTER REPORT
The committee produced an interim letter report in October 2005 (IOM, 2005a). The purpose of this report was to address a component of the charge that had a bearing on the conduct of the AFHS in the time leading up to its scheduled termination date of September 30, 2006. Specifically, the committee applied the information it learned in a May 2005 site visit to the AFHS research facility to the question of “whether or not any obstacles exist to retaining and maintaining the medical records, other study data, and laboratory specimens” collected in the course of the study. The committee believed that it was important to offer findings, conclusions, and recommendations on this topic in advance of its final report to allow for their timely consideration, as the availability of the investigators most familiar with the AFHS data assets and the funding to support them cannot be assured after the end of fiscal year 2006.
RELATED INSTITUTE OF MEDICINE REPORTS
Three IOM reports in the Veterans and Agent Orange (VAO) series have addressed issues directly related to this study. Veterans and Agent Orange: Update 2000 (IOM, 2001) is the first of these. Based on their evaluation of available information, the committee responsible for that report stated:
There is scientific merit in retaining and maintaining [AFHS] medical records and samples, so that—with proper respect for the privacy of the study participants—they could be available for future research. It therefore recommends that the federal government examine whether and how the various forms of data and specimens collected in the course of the AFHS could be retained and maintained, and what form of oversight should be established for their future use. The committee further recommends that consideration be given to whether it is appropriate to continue the study past its planned completion date. (p. 161)
Veterans and Agent Orange: Update 2002 (IOM, 2003) reiterated the findings and recommendations related to retaining and maintaining the data assets and making them available for future research. It went on to state:
The committee recommends continuing the study past its planned completion date…. Given the increased incidence of such diseases as amyotrophic lateral sclerosis, Parkinson’s disease, prostatic cancer, and brain cancer in aging populations and the increasing age of the Vietnam-veteran cohort, research should specifically examine those diseases in the Vietnam veterans. (p. 542)
The most recent (as of 2005) report in the series, Veterans and Agent Orange: Update 2004 (IOM, 2005b), was being conducted during the time this study was initiated. It noted, “Previous VAO committees have recommended extending
the AFHS, and this committee encourages the newly appointed AFHS review committee to consider those recommendations in the course of its deliberation” (p. 492). The legislative history of the Veterans Benefits Act of 2003 does not indicate whether the Update 2000 recommendations to consider whether the AFHS should be extended and examine the disposition of its data assets were influential in the decision to mandate the formation of this committee. To the best of the committee’s knowledge, no other actions were taken in response to the previous committees’ recommendations. This committee is aware of the previous committees’ findings and recommendations but operated completely independent of them and reached its own conclusions based on its own evaluation of the available information.2
ORGANIZATION OF THE REPORT
The balance of this report is organized in five chapters and supporting appendixes. Chapter 2 provides background material for several aspects related to the committee’s charge. It chronicles the development of the military herbicide program and Operation Ranch Hand—specifically, the ensuing controversy and the creation, implementation, findings, and impact of the AFHS. Chapter 3 describes not only the elements comprised by the AFHS data holdings collected and assembled during the course of the study but their accessibility to outside researchers as well. Chapter 4 details the AFHS specimen collection including elements related to specimen gathering, processing, storage, and their potential application to future research. Chapter 5 builds on the material presented in Chapters 2 through 4 related to the scientific merit of retaining and maintaining AFHS data and specimen holdings and discusses some of the associated ethical, legal, and social issues. Chapter 6 contains the committee’s conclusions and recommendations regarding the disposition of the specimen and data assets collected in the course of the AFHS subsequent to its currently scheduled termination date.
Agendas from all public meetings held by the Committee on the Disposition of the Air Force Health Study through June 2005 are provided in Appendix A. Appendix B contains 16 tables pertaining to the endpoints analyzed, covariates included in analyses, and laboratory tests performed as part of AFHS physical examinations. Appendix C comprises a list of the epidemiologic studies related to Vietnam veterans’ health reviewed in the IOM’s VAO series. Appendix D presents an analysis of the statistical power to detect excess relative risks among the AFHS population in a follow-up mortality study. Appendix E—which is excerpted from the IOM report Vaccine Safety Research, Data Access, and Public
Trust (IOM, 2005c)—contains summary information from existing repositories on procedures for asset access application, processing, and associated fees. A final Appendix (F) provides biographic information on the committee members, consultants, and staff responsible for this project.
IOM (Institute of Medicine). 2001. Veterans and Agent Orange: Update 2000. Washington, DC: National Academy Press.
IOM. 2003. Veterans and Agent Orange: Update 2002. Washington, DC: The National Academies Press.
IOM. 2005a. Disposition of the Air Force Health Study—Interim Letter Report. Washington, DC: The National Academies Press. [Online]. Available: http://www.nap.edu/catalog/11483.html [accessed December 1, 2005].
IOM. 2005b. Veterans and Agent Orange: Update 2004. Washington, DC: The National Academies Press.
IOM. 2005c. Vaccine Safety Research, Data Access, and Public Trust. Washington, DC: The National Academies Press.
Michalek JE. 2005 (January 5). The Air Force Health Study: An Overview and Update. PowerPoint presentation before the Committee on the Disposition of the Air Force Health Study, Washington, DC.