The Air Force Health Study Assets Research Program (2015) / Chapter Skim
Currently Skimming:
2 The Air Force Health Study
2 The Air Force Health Study
Pages 21-42
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 21... ...
Air Force personnel (all men) who had participated in Operation Ranch Hand -- the program responsible for herbicide spraying in Vietnam -- had experienced adverse health outcomes as a result of their service.
|
From page 22... ...
Air Force between 1962 and 1971, were stationed in and flew cargo operations elsewhere in Southeast Asia during the Vietnam conflict, had not been exposed to tactical herbicides, and were assumed to be similar to the Ranch Hands regarding lifestyle, training profiles, and socioeconomic factors. Each Ranch Hand was matched to a pool of 8–10 1 The IOM report Disposition of the Air Force Health Study provides a more detailed explanation of the design and results from the mortality and retrospective morbidity study components (IOM, 2006)
|
From page 23... ...
In-home interviews to complete the baseline questionnaire for new participants continued through part 3 The committee notes that the comparison cohort was selected to be comparable to the Ranch Hands, but was not truly matched in an epidemiologic sense because the follow-up time was not identical for Ranch Hands and their comparison subjects if the comparison was replaced over the duration of the study. 4 SAIC was a contract service provider to the AFHS for all exam cycles.
|
From page 24... ...
The follow ing section details the voluminous amounts of health and other types of data collected. Electronic Data Information was gathered through comprehensive physical examinations, questionnaires, and reviews of medical records.
|
From page 25... ...
, PDFs of questionnaires and physical exam forms, and codes, including translation values to those used in data files. Content of the files includes questionnaires and physical exams from all six cycles, some of the analysis files used to create the AFHS reports for each cycle, diagnostic codes, dioxin analyses for cycle 3, dioxin data for cycles 3–6, last known addresses of all cohort members updated in 2007, journal articles and AFHS technical reports, master files to link personally identifiable information to case numbers, medication codes, the questionnaire on exposure to herbicides administered to Ranch Hand ground crew, mortality information updated in 2007, tour of duty histories, and freezer location of specimens (Robinson, 2007)
|
From page 26... ...
Data collected during physical examinations comprise indices of health status that encompassed general health and endpoints by major organ system. Appendix B of the Disposition of the Air Force Health Study report provides an extensive summary of the health outcomes and endpoints collected in the course of the AFHS by cycle and organ system, including the more than 200 laboratory tests performed on the biospecimens.
|
From page 27... ...
measured serum concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other dioxin-like compounds in samples from 777 Ranch Hands and 1,173 comparisons who participated in the 2002 exam cycle.
|
From page 28... ...
Since the previous update in 2003, an additional 155 Ranch Hands and 188 comparisons have died. In all, information and biospecimens are available on 2,210 Ranch Hand and comparison participants, including 757 deceased participants, that can be used in new research studies.
|
From page 29... ...
The AFHS biospecimens are unique in that some types -- such as serum and urine -- were collected longitudinally across multiple cycles, while semen and whole blood were collected at a single exam cycle and adipose tissue was collected only from a subset of individuals in one exam cycle. A separate blood draw was performed to obtain samples for a TCDD (dioxin)
|
From page 30... ...
There are 1,204 participants (556 Ranch Hands and 648 comparisons) with blood serum samples available for all six cycles.
|
From page 31... ...
1982 1985 1987 1992 1997 2002 Specimen Type Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 6 Blood Serum Ranch Hand 858 849 831 799 723 644 Comparison 975 1,027 1,023 1,011 977 924 Total 1,833 1,876 1,854 1,810 1,700 1,568 Whole Blood Ranch Hand 644 Comparison 923 Total 1,567 Urine Ranch Hand 666 840 827 Comparison 580 1,020 1,018 Total 1,246 1,860 1,845 Semen Ranch Hand 668 Comparison 780 Total 1,448 Adipose Tissue Ranch Hand 98 Comparison 144 Total 242 * Available amounts will change as investigators use the specimens.
|
From page 32... ...
Testing of longitudinally collected samples for the same biomarker offers an exceptional opportunity to determine whether changes in a particular biomarker predispose an individual to develop a specific disease or outcome. Types of Biospecimens The AFHS repository contains several types of biospecimens -- some of which are held by relatively few biological sample repositories -- that are valuable because they can be linked to detailed information about the individuals who participated in the study and because they were collected on the same date of the examination cycle, making it possible to determine associations between various biomarkers of exposure and outcomes of interest.
|
From page 33... ...
and to examine DNA methylation marks to make comparisons of chemical exposure-related effects within the tissue. Semen Like adipose tissue, semen is seldom available in biological repositories; in a survey of 261 U.S.
|
From page 34... ...
. Urine Unlike adipose tissue and semen, urine is a relatively common type of sample available in biological repositories because it is easily collected and useful for many types of epidemiologic studies.
|
From page 35... ...
, and are common in biological sample repositories. Whole blood samples can be used to extract DNA that can then be analyzed to provide information on genetic markers of disease predisposition or prognosis.
|
From page 36... ...
. Both the IOM committee and the Ranch Hand Advisory Committee, the interagency workgroup established in 1979 to oversee the AFHS, concluded that the AFHS assets have value beyond studying the effects of dioxin and herbicide exposure on health (RHAC, 2000)
|
From page 37... ...
The committee believes that the identified obstacles are surmountable. • Further study of the AFHS medical records, other study data, and laboratory specimens is advisable.
|
From page 38... ...
. As part of its recommendation to organize and document the assets prior to the scheduled termination date, the committee specified such actions as creating detailed and comprehensive data dictionaries for master data files for each examination cycle; a comprehensive dictionary of the variables contained in the master data files, organized by examination cycle and by questionnaire, physical examination report, or other data intake instrument; a master codebook that would constitute a comprehensive distillation of database contents, such as from which examination cycles a particular piece of information was gathered and the variable name(s)
|
From page 39... ...
Given this, and that the committee concluded that there is scientific merit in retaining and maintaining the AFHS data and biospecimens, the committee further concluded, "Further study of the AFHS medical records, other study data, and laboratory specimens is advisable. The potential value and relevance of extending the study of the AFHS data assets rests in the application of the results of future research on the assets" (IOM, 2006, p.
|
From page 40... ...
2002. Adipose tissue biomarkers of fatty acid intake.
|
From page 41... ...
2006. Testing the viability of stored frozen serum samples from the Air Force Health Study using human multi-analyte profiles (MAP)
|
From page 42... ...
Document given to MFUA upon transfer of AFHS assets. Sabetian, S., A
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.