Approval of Previous Meeting Minutes.
Dr. Stoto announced that the previous meeting minutes were distributed
to RHAC for review and comment. The
draft was modified to reflect Dr. Stoto’s changes on the “Future Use of
Biological Samples” presentation. Dr.
Trewyn suggested that the third bullet on page 8 be revised as follows: “Provide a breakdown of in-country Vietnam
versus other locations where the comparison group served.”
Dr. Stoto entertained a motion to
approve the previous meeting minutes as modified; a motion was properly made
and seconded by Drs. Trewyn and Leffingwell, respectively. The April 30, 2004 RHAC Meeting Minutes were
unanimously approved as modified with no further discussion. Dr. Stoto confirmed that in the future,
draft meeting minutes will be immediately sent to Dr. Joel Michalek, the Air
Force Health Study (AFHS) Principal Investigator for technical review and
comment.
Dr. Michalek covered the following
items in his status report. First, he
gave a detailed briefing to the National Academy of Sciences (NAS) Institute of
Medicine (IOM) panel. Second, he
summarized his presentations at Dioxin 2004 and third, he summarized current
AFHS research.
The purpose of the IOM presentation
was to respond to a critique by the IOM panel of the AFHS cancer paper
published in the Journal of Occupational and Environmental Medicine in
February 2004. An earlier paper,
published in the American Journal of Epidemiology, highlighted a main effects
model in which Ranch Hands with high, low and background exposure levels were
compared to comparisons. The analysis
was published in 1998 and showed no exposure effect.
Based on RHAC’s advice, USAF removed
the main effects model from the analysis and applied new strategies. Most notably, the analysis of cancer
incidence by dioxin category was readjusted to reflect years spent in Southeast
Asia (SEA) and the potential for exposure to Agent Orange. The new analysis showed an effect when
stratified and was driven by a significant interaction in which the
relationship between cancer and dioxin category changed with years in SEA.
An AFHS paper on dioxin and
peripheral neuropathy published in Neurotoxicology in 2002 was also
discussed during the briefing. The data
showed a significant increase in the risk of probable peripheral neuropathy
with increased dioxin category, but the most recent NAS report found the
analysis to be less than convincing.
Moreover, NAS did not conclude that the data suggested an exposure
effect. As a result, the IOM panel is
currently re-analyzing the paper and has asked USAF to provide additional
details on the data and study results.
Second, AFHS data were presented
during the Dioxin 2004 conference in Berlin in September 2004. The insulin sensitivity paper further
explored the diabetes association seen in AFHS participants. The cancer paper displayed trends in
comparisons only to better understand cancer in Ranch Hands. The mortality paper compared mortality
between Ranch Hands and 19,000 comparisons.
Advantages of the analysis include a large sample size and major
covariates of date of birth, rank and military occupation. However, the study is limited because
important covariates of smoking and family history of heart disease in the
19,000 comparisons are not available.
Analyses of the mortality data showed a significant increase in the risk
of cardiovascular death among Ranch Hand enlisted ground crew.
The metabolic syndrome paper showed
an association between metabolic syndrome and subsequent cardiovascular death
in controls, but not among Ranch Hands.
USAF is thoroughly reviewing these data because several outcomes in the
Ranch Hand group are not currently understood, such as a change in the expected
pattern of metabolic syndrome in cardiovascular mortality; increased
cardiovascular mortality in Ranch Hand enlisted ground crew; and lack of an
exposure association among living persons who presented to Scripps Clinic. USAF is reexamining each death among Ranch
Hand enlisted ground crew to determine whether competing risks were overlooked
during the initial analysis.
Third, Dr. Michalek reported on several
additional active research activities.
Prostate cancer and dioxin papers are currently being developed with a
larger database. The additional cases
will provide more opportunities to analyze and display results. All cases of heart disease among Ranch Hand
enlisted ground crew are being thoroughly examined. Responses are being prepared to address issues raised by the IOM
panel on the AFHS peripheral neuropathy paper.
A paper is currently being developed on cancer in the Ranch Hand group
as a follow-up to the paper on cancer in the control group. Recent data are being incorporated into the
new paper to build on trends seen in the control group.
The new paper on the Ranch Hand
group will feature a larger sample size than the paper on the control
group. The data set of controls
contained 355 of 1,700 persons with at least one tumor, while the new data set
of Ranch Hands contains 450 of 800 persons with verified malignancy. However, the Ranch Hands database is still
being updated. The cancer paper will
compare years spent in SEA and cancer risk among personnel who were and were
not in Vietnam. Efforts are underway to
also determine locations of these personnel in SEA, including Japan, Okinawa
and Taiwan.
Dr. Stoto remarked that the ongoing
activities illustrate the value of AFHS data and strong efforts USAF has made
to expand the original study design beyond issues related to health effects
from Agent Orange and other herbicides.
The interesting outcomes USAF is now seeing in controls should be
particularly emphasized while decisions are made about the disposition of
AFHS. Dr. Robert Sills, of the National
Institute of Environmental Health Sciences (NIEHS), was extremely pleased that
USAF responded to RHAC’s previous recommendation to publish AFHS data in peer
reviewed publications. This strategy
has increased the strength and credibility of the data. He commended USAF on its diligent efforts in
compiling and analyzing the wealth of information that has been collected.
RHAC members were assigned the
different health study chapters to review prior to this September 22, 2004
meeting and submitted comments in advance of the meeting or provided written
and/or oral comments at the time of the meeting.
Dr. Leffingwell was charged with the
review of Chapter 19 and Appendix F-11.
His comments along with recommendations by other RHAC members are
outlined below.
• Place
abbreviations for Table 19-2 immediately after the section that is defined
rather than at the end of the table.
• Explicitly
state in Section 19.2.1 that the number excluded did not significantly differ
between groups.
• Repeat
the title of “Analysis of CD3+ Cells” in sub-tables (a)-(h) in Table 19-4.
• Change
line 1628 to “which fights invading organisms such as ...”.
• Italicize
“(Callithrix jacchus)” in the references.
Dr. Sills was charged with the
review of Chapter 8. His comments along
with recommendations by other RHAC members are outlined below.
• Add
asterisks to the tables to more easily identify significant associations, such
as “*p<0.05” or “**p<0.001.”
• Delete
“The purpose of the chapter” on lines 571 and 629 and begin the sentences with
“It was determined whether the covariates used throughout this report ...”.
• Delete
“in this report” on line 631.
• Add
a references section of statistical methods to the chapter to better inform
readers who may be unfamiliar with covariate associations with estimates of
dioxin exposure.
Dr. Hassoun was charged with the
review of Chapter 12 and Appendix F-4.
Her comments along with recommendations by other RHAC members are
outlined below.
• Add
asterisks to the tables to clearly define significance levels, such as “*p <0.05.”
• Add
a reference to clarify that the “Verbal Paired Associates test” described on
line 427 is an algorithm cited from the literature or provided by the Centers
for Disease Control and Prevention on scoring psychological tests.
• Explain
that the “alcohol use” covariate in Section 12.1.3.2 is used as both a covariate
and dependent variable.
• Describe
the “Unadjusted and adjusted analyses for Models 2 and 3” on line 496.
• Add
the maximum possible values for the Wechsler Memory Scale-Revised in Table
12-1. Change the heading of the fourth
column in the table to “Cutpoints/Maximum Scores.”
• Include
text in Appendix F-4 to define significance levels.
• Clarify
in Appendix F-4 that the maximum correlation for Pearson’s correlation
coefficient is 1.0 and the minimum correlation is -1.0.
Dr. Trewyn was charged with the
review of Chapter 16 and Appendix F-8.
His comments along with recommendations by other RHAC members are
outlined below.
• Broaden
the introduction to highlight research on non-dioxin herbicides, related
chemicals and other types of species, such as toxicological studies on 2-4-D
and cacodylic acid. Add a paragraph to
describe the evolution of the study.
For example, the AFHS progressed beyond research on Ranch Hand
occupational exposures to a more comprehensive focus on dioxin due to increased
capacity over time to measure serum dioxin.
• Emphasize
that new analyses are showing hematological effects when adjusted for years
spent in SEA, but this covariate is not reflected in the report. Include language to inform readers that
these data are forthcoming.
• Clarify
that line 126 refers to the “animal species” of dioxin.
Dr. Leffingwell was charged with the
review of Chapter 15 and Appendix F-7.
His comments along with recommendations by other RHAC members are
outlined below.
• Insert
text on lines 398-401 to explain that ECG variables can be mutually exclusive
categories.
• Change
“strongest” to “stronger” on line 441 since only two Doppler signals exist.
• Place
abbreviations for Table 15-1 immediately after the section that is defined rather
than at the end of the table.
• Incorporate
language to explain that significant differences were seen between the number
excluded in Ranch Hands and comparisons for both the “Resting Pressure Index”
and “Family History of Heart Disease Before Age 45" variables in Table
15-2. Clarify that the differences were
seen in both the “Group” and “Categorized Dioxin” categories.
• Repeat
the title of “Analysis of Essential Hypertension” in sub-tables (a)-(h) in
Table 15-3.
• Change
the titles as follows: “Analysis of Abnormal Tibial Pulses” for Table 15-26;
“Analysis of Abnormal Leg Pulses” for Table 15-27; and “Analysis of Abnormal
Peripheral Pulses” for Table 15-28.
Repeat the titles in sub-tables (a)-(h) for the respective tables.
• Italicize
“(Callithrix jacchus)” on line 2784 and “(Orizias latices)” on line 2816.
• Revise
line 2819 to read “cytochrome P5401A.”
• Widen
the space between columns in Table F-7, particularly since the “w” in the
“Enlisted Groundcrew” column is on a line by itself.
• Change
the title of Section 15.1.12 from “Mode of Action” because the text actually
refers to toxicological effects in animals.
• Modify
the “Discussion” section on page 15-112 to immediately present the study
findings rather than discuss cardiovascular disorders. Move the first three paragraphs of the
“Discussion” section to the “Background” section on page 15-1.
Dr. Stoto was charged with the
review of Chapter 7 and Appendix E. His
comments along with recommendations by other RHAC members are outlined below.
• Explain
that the statistical models were used in previous reports and remain the same
for the sake of continuity. However,
emphasize at the beginning of the chapter that different models are used in
AFHS studies published in the scientific literature.
• Outline
the rationale for not adding summary tables to the statistical methods chapter.
• Change
the title of Section 7.2.2.1 to “Prior Knowledge Regarding Dioxin Elimination”
and reorganize the text for clarity.
Add language to discuss the adequacy of serum dioxin measures taken in
1987 and thereafter as proxies of doses received in Vietnam in the 1960s.
• Incorporate
lines 176-183 into Section 7.2.2.1 since this text also refers to serum dioxin
measures.
• Clarify
the assumption in Section 7.2.2.1 that <10 ppt lipid-adjusted dioxin levels
are equivalent to background levels.
• Revise
Model 1 to clarify the underlying assumption that herbicide and dioxin
exposures are proportional, and the latter is not measured or assessed.
• Include
an additional advantage and disadvantage in Model 1: it follows the original AFHS design. The disadvantage is that Model 1 does not incorporate new data on
the degree of exposure and may result in an inaccurate classification.
• Include
an additional disadvantage in Model 2 to discuss the limitations of using body
mass index (BMI) as a covariate to assess health. BMI is not sufficient to fully control for the complex
relationship between dioxin and obesity.
• Revise
“does not account for dioxin exposure after SEA” in Model 2 to clarify that
dioxin was actually measured in 1987 or thereafter. Add text to explain that the estimate in Model 2 is in
response to the interest of AFHS participants in using their initial doses
only.
• Clarify
the assumption in Model 3 that “dioxin body burden has been eliminated with
time.” The model actually assumes a first-order
elimination rate. Also, note that the
model assumes that adding BMI as a covariate may not fully adjust for any
relationship between obesity and the dioxin elimination rate.
• Clarify
the statement in Model 3 that the data are “less dependent on the accuracy of
the estimation algorithm for initial dioxin than Model 2.” Explain that power is actually lost by treating
continuous variables as categorical.
• Revise
the statement that Model 3 “makes no use of prior belief that some Ranch Hands
received unusually large doses in Vietnam”.
It is well documented that some enlisted ground crew actually were
exposed to large doses.
• Add
text in Model 3 to clarify that some comparisons were employed by U.S.
industries, received substantial dioxin doses, possibly through occupational
exposures, and are experiencing approximate first-order elimination, and have
dioxin pharmacokinetics and associations between health and dioxin.
• Modify
Model 4 to illustrate that “ppt” was measured if the result was present in 1992
and extrapolated to 1987 if the lipid-adjusted dioxin level was >10.
• Delete
the advantage in Model 4 of “using 1987 dioxin has less inherent variation than
initial dioxin” because the two models are statistically equivalent.
• In
Section 7.5.5, another approach is to think of a statistically significant but
clinically not meaningful difference as evidence that a fraction of those
exposed might have clinically meaningful differences.
• Replace
“ppq” in the formula on line 139 with a “w” to illustrate wet weight measured
in femtograms.
• Add
text or a footnote to Model 1 to explain that a significant number of
comparisons were stationed in Vietnam.
Dr. Camacho was charged with the
review of Chapter 5 and Appendix C. His
comments along with recommendations by other RHAC members are outlined below.
• Distinguish
between the “hostile” and “final refusal” classifications on line 64.
• Include
additional information to more clearly delineate the “Replacement Protocol” on
page 5-2, such as the number of replacements over the course of AFHS; outcomes
with persons who replaced original comparisons; length of time individuals
remained in AFHS; and number of original participants who remained in AFHS
throughout its duration. Describe
specific components of the algorithm used in the replacement protocol. For example, original comparisons were replaced,
but not replacements. The original
comparison and replacement could participate in AFHS at the same time because
invitations to reenter AFHS were extended to all original participants. Replacements were not assigned to original
comparisons who were deceased, could not be located or refused participation in
AFHS.
• Acknowledge
on line 129 that refusals who were asked to provide “their self-perception of
health” may create a bias in AFHS.
However, explicitly state the benefits and potential problems of this
strategy. Replicate the flow chart in
the statement of work as an appendix to the chapter to further illustrate known
or suspected factors that would influence participation in AFHS.
• Add
language to line 205 to clarify that “no replacement was made if formerly
invited comparisons in a matched set were deceased.” Explain that the Ranch Hand case remained in AFHS in this
instance. Repeat this text in the
“Statistical Methods” chapter.
• Modify
Table 5-3 to illustrate that “Reasons for Refusal by Group” are for 2002 only.
• Explicitly
state on line 320 whether the reasons for refusal based on age, military rank
and race are statistically significant or practically important.
Several overarching comments were
made about the seven chapters reviewed during the meeting. In general, RHAC noted that USAF responded
effectively to its previous recommendation to add summary sections and tables
to the chapters. This text was found to
be extremely helpful. RHAC also pointed
out that the chapters were clear, well written and easy to understand.
In particular, Dr. Sills found the
tables and text in the covariates chapter to be consistent and in the
appropriate order. The chapter
accomplished its goal of determining whether covariates used throughout the
report were associated with estimates of herbicide or dioxin exposures. The data supported the fact that dioxin was
significantly associated with military occupation in which officers, enlisted
flyers and enlisted ground crew had the lowest to highest exposure levels,
respectively. The covariates chapter
also contained a clear explanation of the data to assist readers, particularly
significant associations between dioxin and health measurements on page 8-42.
Dr. Sills commended USAF for citing
research on cardiovascular morbidity and mortality in the cardiovascular
chapter, including study results by the Dow Chemical Company, International
Agency for Research on Cancer, and National Institute for Occupational Safety
and Health. Overall, he was pleased
about the tremendous progress USAF has made in reporting critical AFHS
data. These efforts clearly represent a
model for future studies on potential exposures to hazardous substances and
agents. Dr. Sills recognized USAF’s
diligent efforts in compiling a vast amount of information that has been
collected over the years for AFHS. He
was confident that these activities would result in an outstanding product.
Dr. Stoto was aware that USAF
encountered several difficulties in writing the statistical methods
chapter. For example, the chapter
contains highly technical information, but some readers may have no training or
knowledge in the field. USAF made
outstanding efforts in explaining these complex data to a non-technical
audience. Moreover, models used in the
original AFHS design would not currently be implemented due to more recent data
collected and new statistical capacity developed over time. USAF adequately describes and justifies its
rationale for applying these outdated models.
RHAC suggested that the following
global changes be considered across all chapters of the report. First, table titles should be repeated in
each instance where a table has corresponding sub-tables. Second, “Discussion” sections should be
modified to immediately discuss the findings of the particular chapter. For example, the first few paragraphs of
“Discussion” sections should be moved to “Background” sections. Relevant text in “Discussion” sections
should be repeated in the “Executive Summary.”
Third, USAF should note that Ranch Hands and controls were told their
respective dioxin categories because this knowledge may impact the overall
assessment of well-being.
USAF thanked RHAC for its thorough
reviews of the chapters. In accordance
with general practice, USAF and its contract authors will review, evaluate, and
respond to all RHAC comments that were raised during the meeting and other
editorial changes submitted in writing.
USAF will distribute a matrix to illustrate RHAC’s recommendations and
USAF’s resolution of each comment. Dr.
Stoto asked USAF to report on its resolution of RHAC’s recommendation to revise
“Discussion” sections during the next meeting.
Dr. Stoto provided an update on an action item that was
raised at the previous meeting. RHAC
agreed that Dr. Stoto would write a letter to HHS Secretary Tommy Thompson with
a copy to Congressional staffers and Mr. Anthony Principi, the Department of
Veterans Affairs (VA) Secretary. The
letter would outline the following points.
Congress mandated a study to determine the disposition of AFHS
data. The 2003 Benefits Act directed
the VA Secretary to enter into a contract for the study 60 days after the
legislation was signed on December 16, 2003, but the VA has yet to sign the
contract or provide funds. RHAC is on
record with its concern that the VA has not fulfilled its responsibility according
to the legislation.
Dr. Stoto invited the VA Secretary
or his representative to attend the September 2004 RHAC meeting to discuss this
issue. To date, neither HHS nor the VA
has responded to RHAC’s letter, nor did the VA send a representative to the
meeting Dr. Stoto will extend another
invitation for the VA to attend the next RHAC meeting. He acknowledged RHAC’s awkward position in
this matter because the disposition of AFHS data falls under the purview of
Congress, USAF and the VA, but RHAC’s charter is limited to advising the HHS
Secretary.
Dr. Camacho expressed an interest in raising more
awareness about the disposition of AFHS data and the VA’s failure to fund the
study. He planned to discuss this issue
in a letter to major veterans’ organizations, such as the American Legion,
American Veterans, Disabled American Veterans, Veterans of Foreign Wars, and
Vietnam Veterans of America. Each
organization could then broadly disseminate the letter to its respective
constituency. Dr. Stoto noted that Dr.
Camacho would take this action as an individual citizen rather than as an RHAC
member.
Dr. Leonard Schechtman, the RHAC
Executive Secretary, proposed potential dates for the 2005 meetings: the week of February 14 or 21, 2005 for the
first meeting; the week of May 1 or 23, 2005 for the second meeting; the week
of September 11 or 18, 2005 for the third meeting; and the week of November 1,
2005 for the fourth meeting. Days that
meetings cannot be convened include May 26 and 27, 2005 for the second meeting
and November 1 and 4, 2005 for the fourth meeting. FDA will poll RHAC by e-mail with as much advance notice as
possible to confirm dates. USAF pointed
out that two of the 2005 meetings will be needed to present the final report
and provide an update on closure activities, ongoing research and additional
findings. As a result, USAF estimates
that only two RHAC meetings may need to be convened in 2005. USAF will determine in the near future
whether additional meetings will be needed.
Dr. Schechtman thanked the RHAC
members for completing and submitting their conflict of interest (COI) forms in
a timely manner. The COI form that
needs to be completed for 2005 will be e-mailed to each RHAC member in July 2005. The deadline for completing and submitting
the document to FDA will be two weeks following the mailing. FDA will provide members with a copy of
their respective COI forms for 2004.
Dr. Schechtman noted that HHS
requires Federal Register notices for upcoming meetings to be published
well in advance of the meeting date. As
a result, FDA and RHAC will need to draft agendas no later than 60 days in
advance of the upcoming meeting.
Changes to agendas that will be published in the Federal Register
can be submitted up to 45 days in advance of the meeting. However, only critical modifications that
can be justified will be approved.
Dr. Stoto listed assignments for the
third cycle of reviews that will be conducted during the next meeting. Dr. Trewyn will review Chapter 10-Neoplasia;
Dr. Sills will review Chapter 11-Neurology; Dr. Hassoun will review Chapter
13-Hepatic; Dr. Johnson will review Chapter 14-Dermatology and Chapter
20-Pulmonary; Dr. Leffingwell will review Chapter 18-Endocrine; and all RHAC
members will review Chapter 21-Conclusions and Executive Summary, but Dr.
Camacho will serve as the lead reviewer.
Dr. Kwame Osei will be assigned
Chapter 14 if he is able to attend the next meeting. FDA will provide each RHAC member with the assignment list and
all chapters for the next review cycle.
Dr. Sills commended Ms. Kimberly Campbell, the Committee Management
Specialist, for her outstanding efforts in distributing materials and making
logistical arrangements for the meetings.
Mr. Rick Weidman, Director of
Government Relations for Vietnam Veterans of America (VVA), outlined the
organization’s perspective of AFHS.
Although AFHS has been an ongoing activity for more than 25 years, the
original study questions have still not been answered. AFHS samples and other data gathered to date
will be extremely useful in addressing these issues. For example, Ranch Hands were selected as the study population
because the Department of Defense and VA claimed no evidence had been produced
to validate that individuals were exposed to herbicides. Data collected since that time show that
military personnel, particularly enlisted ground crew, were indeed exposed.
Despite the collection of these
valuable data, VVA has noted several major flaws and is now questioning whether
AFHS should continue in its current form.
First, AFHS was initiated as a study on herbicides, but the original
design will not be useful to Vietnam veterans and their families. AFHS should be expanded beyond its focus on
dioxin to include other chemicals, participants and confounders that may be
relevant to the overall validity of the findings, such as veterans who were
hostile to or non-compliant with AFHS and replacements of original
comparisons. These confounders should
then be compared to a null hypothesis.
The IOM previously considered VVA’s recommendation and reviewed studies
on health effects from PCBs.
Second, no scientific evidence has
been produced to validate that levels <10 ppt are not harmful. Third, AFHS was not designed with a
non-veteran cohort. Time in SEA has been
measured, but no comparative research has been conducted to identify
differences in overall health effects between USAF personnel who served in
Vietnam and non-veterans. AFHS needs
four separate cohorts to clearly make this determination: Ranch Hands, non-veterans, USAF personnel
with no service in SEA, and USAF personnel with service in SEA. Congress authorized and appropriated funds
for AFHS to provide Vietnam veterans and their families, the veterans community
and the American public with confidence that the findings will make a
tremendous contribution in addressing whether Vietnam veterans were
significantly harmed by exposure to herbicides in SEA while serving their
country.
VVA is extremely pleased that Dr.
Stoto wrote a letter on behalf of the RHAC to the HHS Secretary about the
disposition of AFHS data and the VA’s failure to fund the NAS study in this
effort. VVA agrees with RHAC that AFHS
samples and other data should be transferred to the custody of NIEHS and made
available to reputable researchers and legitimate research institutions. VVA plans to file a lawsuit, submit a
Freedom of Information Act request, or take other political or legal actions
that may be necessary if the AFHS data are not made available for further
scientific study. AFHS belongs to the
American public because the research was funded with taxpayer dollars to
determine whether deleterious health effects of Vietnam veterans were related
to their service in Vietnam. Additional
research with AFHS data should be privately conducted and publicly funded
through both requests for proposals and notices of funding availability to
ensure future studies are appropriately designed and tested.
VVA also holds the VA accountable
for not providing funds to support the National Vietnam Veterans longitudinal
study in accordance with Public Law 108-183.
Although NAS is expected to submit a report to Congress on the study in
2005, the VA has yet to enter into a contract.
Despite its concerns, however, VVA acknowledges the contributions of all
current and former RHAC members as well as the dedication and diligent efforts
of USAF and its contractors in collecting and compiling a wealth of information
for AFHS. VVA maintains its confidence
in the VA Secretary, but recognizes that he is being poorly advised by certain
sectors within the VA.
Mr. Weidman also made comments in
response to RHAC’s discussion of its business.
The HHS and VA Secretaries should be asked to consider holding the next
RHAC meeting at VA Headquarters, 810 Vermont Avenue in Washington, DC. This location could increase attendance by
the public and participation by high-ranking VA officials.
Several remarks were made in
response to Mr. Weidman’s comments. Dr.
Stoto clarified that providing guidance to extend AFHS and utilize the data in
future studies are beyond RHAC’s charter.
RHAC is only charged with advising the HHS Secretary on the technical
and scientific merits of AFHS in its current form. However, RHAC certainly agrees that AFHS samples and other data
collected to date are extremely valuable and should be made available to
legitimate researchers in the future.
Dr. Stoto was pleased VVA agreed with RHAC’s position that the VA has
not fulfilled its Congressional mandate to fund the AFHS disposition
study. As a federal advisory committee,
RHAC is prohibited from taking certain actions, but VVA and other private
organizations are free to make external efforts. Dr. Stoto confirmed that Mr. Weidman’s suggestion to hold the next
RHAC meeting at VA Headquarters will be considered.
Dr. Leffingwell agreed that
establishing a referent cohort of the general population rather than USAF
personnel would be a valuable, but daunting effort. Consideration should be given to creating a repository to apply
AFHS data to studies in the civilian population. However, AFHS represents an outstanding body of research and the
ability to maintain the same high level of quality in future studies is
questionable. Dr. Leffingwell also
appreciated external actions VVA will take in ensuring AFHS data are
maintained.
Dr. Trewyn agreed that the AFHS
design is flawed in some areas and RHAC’s ability to make modifications is
limited due to its role as a federal advisory committee. However, he was pleased to note that USAF
acted on its interest and willingness to expand AFHS and publish data in peer
reviewed publications. For example,
USAF is now finding significant differences in the general cancer prevalence
between the civilian population and Vietnam veterans in several ongoing
research projects. Dr. Trewyn hoped
USAF’s additional efforts with the cancer data would provide opportunities for
future research on cardiovascular and other health effects among Vietnam
veterans.
Dr. Michalek explained that USAF and
its peer review panel thoroughly discussed the concept of multiple control
groups when AFHS was conceived in the mid-1970s. Due to budget limitations, AFHS could only be designed with one
control group. USAF ultimately selected
the control group of personnel stationed in SEA due to the realization that
exposures may exist in SEA alone regardless of Agent Orange. Dr. Johnson underscored the critical need to
obtain appropriate consent from AFHS participants if the data are used in the
future for other research. He also
emphasized that AFHS samples and other data should not be used for any purposes
beyond the original intent.
The next RHAC meeting will be held
on November 19, 2004. Dr. Stoto thanked
the members for reviewing their respective chapters; USAF and its contractors
for their diligent efforts in compiling the data; FDA staff for making
logistical arrangements for the meeting; and members of the public for their
attendance.
Dr. Stoto adjourned the meeting at
11:16 a.m. with no further discussion or business brought before RHAC.
I
hereby certify that to the best of my knowledge, the foregoing Minutes of the
proceedings are accurate and complete.
________________________________ ______________________
Michael A. Stoto, Ph.D. Date
Chair
Ranch Hand Advisory Committee
_______________________________ ______________________
Leonard M. Schechtman, Ph.D. Date
Executive Secretary
Ranch Hand Advisory Committee
