1 15 4 https://www.nal.usda.gov/exhibits/speccoll/files/original/0397ef45f6a5749c72a829b6264147b2.pdf e95d695e5c8772b844e37ed1186077ad PDF Text Text Item ID Number 01734 Author Houk, Vernon N. Corporate Author RepOrt/ArtiClB TltlO Memorandum: Review of VA Mortality Study, from Vernon N. Houk to Ronald W. Hart, September 11, 1987 Journal/Book Title Year 000 ° Month/Day Color D Number of unaoos 2 Desorlpton Notes Monday, June 11, 2001 Page 1785 of 1793 �DEPARTMENT OF HEALTH & HUMAN SERVICES Public Health Service Centers for Disease Control Memorandum Date From .September 11, 1987 Director Center for Environmental Health and Injury Control Review of VA Mortality Study Subject To Ronald W. Hart, Ph.D. Director National Center for Toxicological Research i The Veterans Administration (VA) has conducted a proportionate mortality study (PMR) of 24,235 deaths among U.S. Army and U.S. Marine male veterans who served in Vietnam and 26,685 deaths among male veterans of the same two services who did not serve anywhere in Southeast Asia. All deaths were identified from the VA BIRLS file and occurred between July 4, 1965, and March 1, 1982. These deceased veterans had to have served in the military sometime between July 4, 1965, and March 1, 1973. Career and non-career, officers, and enlisted men, as well as reservists, were included. In-service deaths occurring before 1974 and men dying from war-related injuries were excluded. In service deaths after 1973 were included. Within the group of Vietnam veterans, the fraction of all deaths attributable to a particular cause was computed and compared to the corresponding proportion for non-Vietnam veterans. The comparison was done using the proportionate mortality ratio (PMR) technique in which age at death, race, and branch of service were taken into account. There was no adjustment for calendar year of death or rank. Altogether, PMRs were computed for 18 major cause of death groupings and for 23 specific cancer sites. We will address our concerns in data collection, data analysis, and interpretation. Data Collection. Are the BIRLS tapes truly at least 94 percent complete? From the CDC Mortality Study which used multiple sources of mortality we found that BIRLS was less complete. Data Analysis. Why do the authors emphasize only the statistically significant positive findings? Why were not the significant decreases in deaths from genitourinary diseases (Table 3) and the decrease in deaths *. from all cancers for one-tour of duty veterans (Table 5) not discussed? The lack of association between service in be reevaluated in light of the CDC finding in the first 5 years after discharge. CDC discharge rather than year of death. This Vietnam and suicide needs to that they were increased only used the time period since subject was repeatedly brought �Page 2 - Ronald W. Hart, Ph.D. up with the VA prior to completion of their analysis. The CDC study would indicate that grouping by 10 year periods would minimize the effect. The findings for lung cancer and NHL in Marine Vietnam veterans are provocative, although similar observations were not made in other studies of Vietnam veterans. The absence of unusual mortality from soft-tissue cancers is consistent with some previous studies but at variance with others. Because so many statistical tests were done on the data set, these ^apparent findings could be due to chance. It would be helpful to see a more detailed analysis in which mortality from these cancer sites is examined by calendar year in Vietnam, rank, MOS, and principal duty. These additional analyses would help in deciding whether some factor related to the Vietnam experience is responsible for the apparent association. Interpretation. The authors suggest that these were major differences in the findings of previous studies cited, but there are in fact few major differences in the findings. Referenced studies were not critically discussed. There has never been, for example, an association demonstrated between lung cancer and phenoxy herbicides except in the Zack Study (Ref. 29) where 3.6 cases were expected and 6 were found in those exposed to 2,4,5-T. Those authors state that they cannot evaluate trends in lung cancer deaths as they relate to occupation because of "limitation in the data." As noted above, it is not surprising to encounter the small number of statistical departures from expected mortality seen in this study. These could easily have arisen by chance alone. This study, as originally designed, cannot conclusively clarify mortality risks for Vietnam veterans, let alone elucidate possible causative factors within, or outside of, the Vietnam experience. Reasons include lack of a defined population-at-risk, incomplete ascertainment of deaths, and absence of "exposure" data on individual veterans. This PMR study appears to be well executed in mechanics. However, the presentation and discussion of the results do not provide the necessary caution in interpretation and allow the uninitiated to make causal inferences where they do not exist. Vernon N. Houk, M.D. Assistant Surgeon General � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 066 Folder The folder containing the original item. 1784 Series The series number of the original item. Series III Subseries III Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Houk, Vernon N. Title A name given to the resource Memorandum: Review of VA Mortality Study, from Vernon N. Houk to Ronald W. Hart, September 11, 1987 Subject The topic of the resource VA Mortality Study BIRLS study criticism cancer risk assessment ao_seriesIII https://www.nal.usda.gov/exhibits/speccoll/files/original/063bb16d96e7401f4e4643efa67413a3.pdf 91410704d340733b48e2ed1c52d0fb24 PDF Text Text Item ID Number 01731 Author Fingerhut, Marilyn Corporate Author RdpOrt/ArtiClO TltlB Typescript: Comments on "Proportionate Mortality Study of Army and Marine Corp Veterans of the Vietnam War" by P. Breslin et al., Septembers, 1987 Journal/Book Title Year 000 ° Month/Day Color Number of Images D 1 Descrlpton Notes Monday, June 11, 2001 Page 1782 of 1793 �Comments on "Proportionate Mortality Study of Army and Marine Corp Veterans of the Vietnam War" by P. Breslin et_ al. Marilyn Fingerhut September 6, 1987 Use of BIRLS for a PMR study is reasonable. Structure of PMR study is reasonable: Random sample of complete file of BIRLS, with Vietnam exposure confirmed; death certificates obtained (96.9% followup), adequate size (at least for Army). PMR studies are usually used to generate, not test hypotheses. The article appropriately recommends further work to evaluate etiological factors. The media reports have not conveyed this information. The problem at hand results from the timing of the release of the article, and the inclusion of a sentence in the Abstract (inappropriately) referring to Agent Orange exposure. The structure of the study is appropriate; the scientific weakness of the article lies in the analysis and interpretation of the results. The authors can revise the article for submission to a journal. The weakness of the article results from 1) the absence of data evaluating elevations in other smoking related diseases in the Marines, 2) absence of latency evaluations for the malignancy outcomes, 3) lack of data evaluating the adequacy of the marine comparison group, and 4) inadequate evaluation of the limitations of the PMR study design. No evaluation of latency is presented for lymphoma or lung outcomes. Service was '64-'73, deaths were '65-'82. The article does not evaluate the relationship of time of exposure to time of death. No data are provided to show whether other circulatory or respiratory deaths were elevated in army and marines for conditions associated with smoking. It is unclear whether the cancer outcomes were obtained in the overall PMR, or in a separate Proportionate Cancer Mortality Ratio (PCMR). The results for deaths from external causes and accidental poisonings are consistent with other studies of veterans and point out problems for veterans following this war. The nonVietnam comparison group for the Army is large, so the numbers can be expected to be stable; the same may not be true for the marines. It would have been helpful if, 1) the authors had carefully presented data to show that the marine Vietnam vs. nonVietnam populations were truly comparable, and 2) the authors had provided a table showing the expected numbers for each cause of death if the national population had been used as the comparison. � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 066 Folder The folder containing the original item. 1781 Series The series number of the original item. Series III Subseries III Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Fingerhut, Marilyn Title A name given to the resource Typescript: Comments on "Proportionate Mortality Study of Army and Marine Corp Veterans of the Vietnam War" by P. Breslin et al., September 6, 1987 Subject The topic of the resource VA Mortality Study BIRLS study criticism cancer risk assessment ao_seriesIII https://www.nal.usda.gov/exhibits/speccoll/files/original/285a52c91cc9bb6701469d9df47df868.pdf 8e3e0bb965d252752bede41996596c0d PDF Text Text Item ID Number °1805 Author Corporate Author Report/ArUde Title Typescript: Minutes, CSP#256, Protocol #1 Coordinating Group Meeting held by Telephone Conference Call, January 5,1984 Journal/Book Title Year 000 ° Month/Day Color [J Number of Images 5 DOSCrlPtOD NOtBS Avn ' ' L- Young filed this item under "Vietnam Veterans Twin Study." Wednesday, July 11, 2001 Page 1806 of 1870 �REFERENCE SUP TO (Name or litlo-Mait roulini aymbalt INITIALS-DATE '•CSP //256, Consultant Oversight Group Protocol til . - • a - Chief CSP - Miami Staff Assistant, CSP ~ VACO ••VETS Project Staff - St. Louis NAS -MFUA Staff w Washington, B.C. «• Agent Orange Project Office Staff - WA., D.C.v^ Rose David son f Contract Officer - VACOl *. " Piet Harris, Contract Officer - NAS REASON FOR flBFERSNCE LJA» HEQOESTED LJron voun riuee LJ NOTE AND RETURN LJ COMMENTS LJ IN FORMATION. LJ pen CONVERSATION I—I I LjSIONATURE I NECESSARY ACTION REMARKS Attached are the minutes of the recent Coordinating Group Meeting on CSP 0256, Protocol //I, FROM DATE I IXZ JACK GOLDBERG , Ph.D., /]/" . / Study Epidemiologist, lotfes VA CSPCf 51K VA FORM Mnn* MAY t«ao 3230 ttXlSTINO 1TOCK* Of VA AUS «»vt, WIUL as used. fonu »iw, 1/19/84 T6U. EXT. ^ w ^ s > O i y j 0 < ,v8J.t06.2M �MINUTES CSP #256, Protocol #1 Coordinating Group Meeting held by Telephone Conference Call 01/05/84 Present: William True, Jack Goldberg, Dennis Robinette Minutes of the meeting held on November 29, 1983 were approved as read and will be distributed to all parties. I. ACCOMPLISHMENTS TO DATE A. Communications with States Virginia Has sent two tapes containing raale/male twin pairs to NAS. A formal application now has to be filed with Virginia so that the twins identified can be contacted. California California has requested that NAS file a formal application to use their twin register. The California Review Committee meets month. once a Dennis is filling out forms sent by California. Texas No new information regarding the Texas birth certificate search. Connecticut Forms have been submitted to the Connecticut review group. We are awaiting approval. New Yo rk No new information regarding the computerization of the New York twin register. -1- �B. WORK AT NPRC 1. Computer System The abstraction screens for data entry 2. are nearly completed. Twin Search Procedures The process of determining which Connecticut twins were in the military is continuing. This process is based on the "name only" strategy. Dennis indicated that the search for additional temporary staff at NPRC is under way. 3. NPRC Registry Search The NPRC Registry search will not be done using a GSA subcon- tract as was described in the 11/19/83 coordinating group min- utes. Dennis indicated that it will be cheaper for NAS to write the computer matching programs than to have it done contract. under sub- Mr. Joe Griffin, Head of Computer Operations at NRPC has agreed to provide Dennis with computer tapes of the. 10 mil- lion Vietnam era veterans contained on the NPRC register. C. Subcontract Arrangements No new subcontract arrangements have been made. D. Work on DMDC Files No new work on the DMDC files has been performed. E. Zygosity/Morbidity Questionnaire Development The zygosity/morbidity questinnaire has not OMB. Jack yet been submitted to indicated that it would be submitted within the next few weeks. F. Development of a Procedures Document for the NPRC Search The procedures manual describing the abstraction process is nearing completion. -2- �II. AREAS OF SPECIAL ATTENTION A. Contract Between VA and NAS The final contract between VA and NAS has not been signed. counsel has indicated that NAS legal cannot maintain the twin register after the conclusion of the VETS project. twin VA If NAS would maintain the register, it would be in clear violation of the law, according to the VA legal counsel. Decnis indicated that he is not stopping work at NAS or NPRC; he believes that this matter can be resolved between the NAS and VA lawyers. However, Dennis stated that NAS not let any could subcontracts until the final contract is signed. This means that NORC and the State of New York have not received a subcontract from NAS. NORC does not appear to be worried by this and is continuing to provide assistance in the development of and pretesting the zygosity/morbidity survey. New York has not and will not be- gin to computerize their twin register until a subcontract is re- ceived from NAS. B. Problems With Obtaining Social Security Numbers Larry Hobson has been negotiating with the Social stration Security Admini- to obtain social security numbers for twins identified from state twin registers. Bill has indicated that Hobson is having difficulty some in getting the Social Security Administration to agree to provide social security numbers. Hobson recognizes the importance of obtaining C. Social Security cooperation and is working on the problem. Quality Control in Abstraction and Data Entry Dennis suggested that an informal system of quality control to monitor the abstraction and data entry process. a system where the NAS supervisor at NPRC would ter's work on be used Dennis described review an abstrac- an irregular basis during the course of the project. Jack Goldberg objected to this plan noting that a more formalized system of quality control is necessary. Jack suggested that a random sample of records be reabstracted during the project. Bill entire length of the True suggested that this was a problem that might be discussed at the upcoming Consultant Oversight Group meeting. -3- �III. TASKS TO BE COMPLETED BY THE NEXT COORDINATING GROUP MEETING A. VA Tasks 1. The zygosity/morbidity survey should be submitted to OMB. is 2. continued from the list This of tasks from the last meeting. A request to VACO to obtain a BIRLS file of potential twin pairs, This file will be constructed based on same last name, different first name, same state of issuance of the social security number and same date of birth. 3. B. Check with Larry Hobson to determine if any progress has made with the Social Security Administration. been NAS Tasks 1. Determine the number of twin pairs on the Virginia tapes. 2. Submit formal applications to all remaining access to the state twin registers. states to obtain 3. Develop a description of how NAS proposes to conduct the mortality study outlined in CS? #256, Protocol #2 (p. 129-133). 4. The abstraction of military records at NPRC should begin. 5. Complete the procedures document describing the NPRC search and abstraction process. 6. Develop additional information on the completeness of the DMDC file compared to the Connecticut twin register. IV. NEXT IMPORTANT DATES The next coordinating group meeting will be held in Washington, D.C. on Wednesday, January 31, following trie conclusion of the COG-1 meeting. � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 067 Folder The folder containing the original item. 1805 Series The series number of the original item. Series III Subseries III Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Typescript: Minutes, CSP#256, Protocol #1 Coordinating Group Meeting held by Telephone Conference Call, January 5, 1984 Subject The topic of the resource Vietnam Experience Twin Study BIRLS DMDC NPRC ao_seriesIII https://www.nal.usda.gov/exhibits/speccoll/files/original/1516419f8d411753953829faab4f24e5.pdf 8c8791b180b3fd5c1fda29c7cd2fddba PDF Text Text ItemDNunber °1045 Author Eisen, Seth Corporate Author Roport/Artldo TltlO TyPesci"iPt: The Vietnam Era Twin (VET) Registry: Method of Construction Journal/Book Title Year 000 ° Month/Day n Number of Images DOSCrlDtOn NOtBS 16 Alvin L - Young filed this item under "Vietnam Veterans Twin Study." Wednesday, July 11, 2001 Page 1846 of 1870 �The Vietnam Era Twin (VET) Registry: Method of Construction Seth Eisen, M.D. Research Service, St. Louis VA Medical Center, St. Louis, MO and Washington University School of Medicine William True, Ph.D. Psychiatry & Research Services St. Louis VA Medical Center, St. Louis, MO and St. Louis University School of Medicine Jack Goldberg Ph.D. University of Illinois, School of Public Health and Hines VA Cooperative Studies Coordinating Center, Hines, IL William Henderson, Ph.D. Hines VA Cooperative Studies Coordinating Center,Hines, IL C. Dennis Robinette, Ph.D. Medical Follow-up Agency, National Academy of SciencesNational Research Council, Washington, D.C. Work Performed at: Research Service, St. Louis VA Medical Center, St. Louis, MO; Cooperative Studies Program Coordinating Center, Hines VA Medical Center, Hines, IL; Medical Followup Agency, National Academy of Sciences-National Research Council, Washington, D.C. Acknowledgment of Funding: Cooperative Studies Program, Study #256, Veterans Administration Medical Research Service Correspondence: Seth Eisen, M.D. (151A-JB), St. Louis VA Medical Center, St. Louis, MO 63125, USA Running Title: VET Registry: Construction �VET Registry: Construction ABSTRACT A Vietnam Era (1964 - 1975) Twin Registry of American male-male veterans born between 1939 and 1955 has been developed to provide / a study sample for research evaluating the impact of Vietnam service on the medical and psychosocial aspects of health. In preparation for developing the Registry, several alternative sources of twins and methods for identifying twins were investigated. A computerized database of veterans discharged from the military after 1967 was selected as the source because it contains about fifty percent of the total Vietnam era veteran population, is reasonably unbiased, and provides a feasible method for identifying twins. Twins were identified using an algorithm which involved matching entries on the database for same last name, different first name, same date of birth, and similar social security number. Twin status was confirmed by review of military records. The registry, now complete, is composed of 7,400 twin pairs. It will be an important resource for future research projects. �VET Registry: Construction Key Words: Twins, Registries, Vietnam War, Veterans �VET Registry: Construction INTRODUCTION In the wake of America's reassessment of its attitudes towards the Vietnam War, persistent and increasing concern has developed t about possible long-term psychological and physical effects of the war on its servicemen.^ Consequently, the Veterans Administration (the government agency responsible for providing services to American veterans) has been encouraging research to clarify the relationship between Vietnam military service and current health. The Veterans Administration's Medical Research Service, Cooperative Studies Program has provided funds to perform the Vietnam Era Twin Study (VETS), a research project which will assess the long-term effects of the Vietnam experience on health by studying twin pairs where both siblings served in the military during the Vietnam era. The first step in the project was the development of a registry of Vietnam era twin pairs. paper describes the construction of this registry. The present A companion paper (5) examines the issue of bias in the registry. �VET Registry: Construction METHODS AND RESULTS Eligibility Criteria Eligibility criteria for entry into the, Vietnam Era Twin (VET) Registry are: male-male monozygotic and dizygotic twins born between 1939 and 1955 where both siblings served in the armed forces of the United States between 1964 and 1975. Approaches to the Ascertainment of Veteran Twin Pairs Two general approaches are available for identifying veteran twin pairs. The first starts with state based twin registries and attempts to determine whether the known twins on the state registries served on active duty during the Vietnam era. The second starts with computerized records of individuals with known military duty during the Vietnam era and attempts to identify twin pairs. Both approaches were piloted to determine the best method for constructing the VET Registry. 1. State Based Twin Registries Twin registries are maintained by several states in the United States. For example, the States of California, Virginia, and Connecticut have computerized registries of twins identified at birth using birth certificates (1,3). It is important to note that these registries do not continue to collect data on twins as they age. The process for identifying the subset of twins found on state registries who meet the VET Registry eligibility criteria was pilot tested with 55 twin pairs randomly selected from pairs born in the state of Connecticut during the years of �VET Registry: Construction interest. The selected pairs were matched against a comprehensive computer based list of discharged servicemen. list of discharged servicemen and their military records are located at the National Personnel Records Center (NPRC), St. Louis, Missouri. Because the NPRC contains 70 (including those of approximately nine million veterans), no uncommon names exist. The comprehensive million records Vietnam era The only relevant information coded on the computer file are names, social security or military service numbers, and military record location numbers. The matching of the 55 Connecticut twin names with the NPRC computer file produced thousands of potential twin pairs. Many names could be eliminated though, either because both twins were not listed or because the social security or military record location numbers excluded the particular names from military duty during the Vietnam era. typically matched pairs. Still, many names (sometimes hundreds) It was then necessary to obtain the stored military records and compare places of birth and parents names to determine whether a matched pair were in fact twins. 2. Computerized Records of Military Service The National Personnel Records Center (NPRC) To identify potential twin pairs using the NPRC location registry, a matching algorithm using two variables on the computerized data file (name and social security number) was developed. The social security number is a nine-digit �VET Registry: Construction identification number issued to every American wage earner as part of the national retirement system. The first three digits of the social security number indicate the state in which the application was made. The next two digits are encoded to reflect the year of application. It was assumed that twin siblings made application for their social security numbers in the same state, at the same social security office, and on approximately the same date. Therefore, the first three digits of the social security number would be the same for twins and the subsequent six digits would be very similar. The twin status of matched pairs was confirmed by review of military records located at the NPRC. The Bonus State Files Following the Vietnam War, the following states in the United States offered monetary awards to discharged veterans who served during the Vietnam era: Illinois, Indiana, Iowa, Minnesota, New Hampshire, North Dakota, Ohio, Pennsylvania, South Dakota, Vermont, and Wisconsin. Veterans applied to the state in which they lived for their Vietnam era service "bonus". states Many of the developed computerized application and disbursement records which can be used to identify potential twin pairs. While states varied in the data elements which were entered into the bonus files, and a social required was most contained name, sex, race, date of birth, security number. To identify twins from these files developing a computer matching algorithm. Twin status confirmed by reviewing military records at the NPRC. �VET Registry: Construction The Beneficiary Identification and Record Locator Subsystem (BIRLS) The BIRLS, a computerized listing of veterans who have filed for a benefit with the Veterans Administration, is maintained in a standard format and includes name, date of birth, race, and social security number (15). identified Potential twin pairs were by developing a computer matching algorithm similar to those previously described. Confirmation of twin status required examination of military records at the NPRC. The Defense Manpower Data Center (DMDC) The United States Department of Defense, at the Defense Manpower Data Center (DMDC), maintains a computer file of servicemen who were discharged from active military duty beginning in 1968. DMDC claims to have a complete listing of all discharges after 1972; between 1968 and 1972, the proportion of all discharges contained The in the DMDC computer files is unknown. The DMDC computer files contain between four and five million Vietnam era veterans (about fifty percent of all Vietnam era veterans) (14). Potential twin pairs were identified using a matching routine based on name, date of birth, and social security number. Confirmation of twin status was performed by military record review at the NPRC. Summary of Approaches of the Ascertainment of Veteran Twin Pairs A summary evaluation of possible sources of veteran twin pairs is presented in Table 1. Feasibility and bias are the two criteria 8 �VET Registry: Construction which form the basis for evaluation. Feasibility addresses the issue of whether it is possible to construct a large twin registry from a particular data source given the constraints of time and money. Bias addresses the issue of whether a systematic error in the ascertainment source might substantially compromise the subsequent utility of the VET Registry. (Insert Table 1 About Here) The major advantage of state twin registries is that they contain the universe of twin pairs born in a state during a specified time period and are therefore unlikely to be biased. However, since state registries usually contain a limited amount of information, determining whether both members of a pair served on active military duty during the Vietnam era is time consuming and expensive. Using the NPRC registry as a source of twins is also not feasible; the scant number of variables and the large number of veterans included on the registry precludes the development of a computer matching algorithm that has sufficient sensitivity. Both the Bonus State files and the BIRLS can be used to identify twin pairs at low cost. However, the potential for health related bias is large, since both members of a twin pair must have applied for a bonus or Veterans Administration benefit. The DMDC database permits rapid and low-cost identification of potential twin pairs. A known bias in this database is that it contains records for only those veterans who were discharged beginning in 1968. �VET Registry: Construction After carefully considering the advantages and disadvantages for constructing the twin registry from each of the above sources, the DMDC database was selected because it contains a '• r large proportion of the total Vietnam era population (about 50 percent), is reasonably unbiased, and is a feasible method for identifying twins. Final Method of Identifying Twin Pairs in the DMDC Database Only about 12 percent of pairs of DMDC registry members who had the same last name, different first names, same date of birth, and the same first three digits of the social security were demonstrated to be twins after review of their numbers military records. This twin identification rate was too small to be an economical method for construction of the VET Registry. Narrowing the criteria to include matching on the first five digits of the social security number, however, increased the proportion of possible pairs proven to be actual pairs to 50 percent. Therefore, this was the final matching criteria selected for construction of the Registry. The Registry is now complete. It contains 7,400 twin pairs. The addresses of Registry members are currently being obtained and a zygosity determination (13) and health survey questionnaire is being mailed. 10 �VET Registry: Construction DISCUSSION The present paper describes the construction of a new, large (7,400 pairs) twin registry which is based on military service during the Vietnam War era. The study of twins offers unique opportunities for understanding the role of genetic and environmental factors in a wide variety of normal biologic processes and diseases (6,11). The availability of registries of twins substantially facilitates the use of twins in research. Twin registries have been constructed using many different methods. These include all volunteer registries (for example, the Kaiser-Permanente registry) (4), disease focused registries (for example, the UCLA Registry for Genetic Studies in Autism) (12), registries where all members share a common, significant event (for example, the NAS-NRS Twin Registry of World War II veterans) (7), registries composed of a carefully constructed sample of a total population (for example, the registry developed from the National Health Examination Survey) (10), and national registries (for example, the Norwegian and Swedish registries) (2,9). The registry described in the present article is event focused, since it is based on male-male twins born between 1939 and 1955 where both members of each pair served in the armed forces of the United States during the Vietnam era. It was constructed from a computer data file provided by the Department of Defense, Defense Manpower Data Center, which contains a list 11 �VET Registry: Construction of servicemen discharged from active military duty beginning in 1968. The major advantages of the VET Registry are that it is t large and composed of a relatively young twin cohort who can be followed for many years. A detailed examination of ascertainment bias in the identification of twin pairs in the VET Registry is presented in a companion paper (5). It should be noted that Registry members are likely to be both physically and psychologically healthier then the general male population born between 1939 and 1955 (8). The NAS-NRC Twin Registry of World War II veterans is similar to the VET Registry. Both are composed of veteran twin pairs. The NAS-NRC Twin Registry was assembled by matching the names and dates of Caucasian multiple births between 1917 and 1927 provided by 42 state vital statistics offices with a VA master index which contained 99% of all World War II veterans. Twinship was confirmed by review of military records. About 16 r OOO twin pairs were identified (7). used This registry has been extensively to support diverse and important research projects. broaden the The VET Registry will supplement and substantially usefulness of the NAS-NRC Twin Registry. The VET Registry will be administered in a manner similar to the NAS-NRC Twin Registry. Access to the Registry will be overseen by the Committee on Epidemiology and Veterans Follow-up Studies, Division of Medical Sciences, National Academy of 12 �VET Registry: Construction Sciences-National Research Council. The Committee will review submitted proposals for scientific validity and encourage use of the Registry in a manner which insures long-term participation of the twins in research efforts. The first use of the Registry will be to support the VETS research project. It is expected that outside requests for access to the panel will be considered after 1989. 13 �VET Registry: Construction REFERENCES 1. California Bureau of Vital Statistics and Data Processing: Processing Procedures for Twin Study File. Unpublished document, March, 1984. 2. Cederlof R, Lorich U (1978): The Swedish Twin Registry. Prog Clin Biol Res 246(pt B):189-95. 3. Connecticut Division of Health Statistics: Multiple Birth Tape Layout. 4. Friedman GD, Lewis AM (1978): The Kaiser-Permanente Twin Registry. 5. Unpublished Document, October, 1980. Prog Clin Biol Res 24(pt B):173-7. Goldberg J, True Wm, Eisen S, Henderson Wm, and Robinette CD: The Vietnam Era Twin (VET) Registry: Ascertainment Bias. Acta Genet Med Gemellol (Roma), submitted. 6. Hrubec Z, Robinette CD (1984): The study of human twins in medical research. 7. N Engl J Med 310(7):435-41. Jablon S, Neel JV, Gershowitz H, Atkinson GF (1967): The NAS-NRC Twin Panel: methods of construction of the panel, zygosity, diagnosis, and proposed use. Am J Human Genet 19:133- 161. 8. Kendler KS, Holm NV (1985): Differential enrollment in twin registries: its effect on prevalence and concordance rates and estimates of genetic parameters. 34(3-4) :125-40. 14 Acta Genet Med Gemellol (Roma) �VET Registry: Construction 9. Kringlen E (1978): Norwegian twin registers. Prog Clin Biol Res 24(pt B):185-7. 10. McDowell AJ (1978): Twin Data Available from the National f Health Examination Surveys. 11. Nance WE (1984): The relevance of twin studies to cardiovascular research. 12. Prog Clin Biol Res 24(pt B):197-201. Prog Clin Biol Res 147:325-48. Ritvo ER, Freeman BJ, Mason Brothers A, Mo A, Ritvo AM (1985) : Concordance for the syndrome of autism in 40 pairs of afflicted twins. 13. Am J Psychiatry 142(1):74-7. Sarna S, Kaprio J, Sistonen P f Koskenvuo M (1978): Diagnosis of twin zygosity by mailed questionnaire. Hum Hered 28(4) :241-54. 14. United States Department of Defense, Defense Manpower Data Center: Data Base Profile and Overview. Unpublished document, October, 1982. 15. United States, Veterans Administration: Beneficiary Identification and Records Locator Subsystem. document, April, 1968. 15 Unpublished �VET Registry: Construction Table 1 - Potential Sources of Veteran Twin Pairs ASCERTAINMENT IMPLEMENTATION SOURCE BIASES FEASIBILITY State Twin time consuming and Registries costly National Per- time consuming and sonnel Records none likely costly none likely Center Registry Bonus State rapid and low cost Files biased toward veterans who requested a "bonus" from the state Beneficiary rapid and low cost biased toward VA benefit applicants Identification and Record Locator Subsystem (BIRLS) Defense Man- rapid and low cost biased towards power Data veterans discharged Center (DMDC) after 1968 16 � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 068 Folder The folder containing the original item. 1845 Series The series number of the original item. Series III Subseries III Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Eisen, Seth William True Jack Goldberg William Henderson C. Dennis Robinette Title A name given to the resource Typescript: The Vietnam Era Twin (VET) Registry: Method of Construction Subject The topic of the resource Vietnam Experience Twin Study NPRC BIRLS DMDC ao_seriesIII