Disposition of the Air Force Health Study Michael A. Stoto, PhD Institute of Medicine April 14, 2005
Disclaimers I chair the official advisory committee in my personal capacity –Not a RAND project Some information from AFHS Opinions are my own, based on following the study closely for a decade –Not Air Force, RHAC, RAND, or NAS/IOM
Outline AFHS as a national resource to study –Agent Orange and Vietnam herbicides –Dioxin –Veterans’ and occupational health issues –Aging –Chronic disease risks –Other environmental health issues Disposition options and issues
Congressional and Presidential mandate To conduct a 20-year prospective epidemiological study of herbicide exposure and health, mortality, and reproductive outcomes in veterans of Operation Ranch Hand AFHS Purpose
Study Design Index group: Ranch Hand veterans (N=1,208) Control population: Air Force veterans of Southeast Asia (N=19,080) Examined controls matched on age, race, military occupation (N=1,668)
Study Design (Continued) Multiple endpoints –Mortality, morbidity, reproductive outcomes Repeated physical examinations, interviews and mortality assessments, plus –Biological samples –Medical records –Military and civilian employment history Herbicide and dioxin exposure based on military records, military occupation, serum dioxin measurement
Morbidity Endpoints General Health Cancer Neurological Psychological Gastrointestinal Dermatological Endocrinological Immunological Pulmonary Cardiovascular Renal
Study Schedule Protocol Development Physical Examination Exposure period
Serum dioxin (ppt) With chloracne Without chloracne New Zealand sprayers German plant workers quintile 5 quintile 4 quintile 3 quintile 2 NIOSH workers - quintile 1 Enlisted men - non-flying Enlisted men - flying Officers - flying (pilots) Officers - flying (navigators) Officers - non-flying Controls High Medium Low Controls Median serum dioxin levels in selected populations ,600 Ground troop veterans in AOVS Ranch Hand veterans Occupational exposures Seveso, Italy population ,000
Numbers of Veterans Physically Examined YearRanch HandComparisonTotal ,045 1, ,224 1,293 1,299 1,281 1,252 1,174 2,269 2,309 2,294 2,233 2,121 1,951
Study Materials ItemNumber Biological specimens X rays Physical examinations Questionnaires Death records Viable conceptions Nonviable conceptions 74,577 19,594 13,177 20,645 2,819 6,801 1,490
Knowledgeable Staff
Research Results
Study Disposition Veterans Benefits Act of 2003 (PL ): NAS study to address (among others) –Potential value of extending the study –Scientific merit of retaining and maintaining medical records, specimens, other data –Obstacles to retaining materials –Advisability and cost of making specimens available to independent researchers
Extending the Study Due to age and number of remaining participants, value of extending the study to do more physical examinations is not clear Consider –Value of completing research in progress –Monitoring mortality
Retaining and Maintaining Materials Not the original goal, but the result is a –Longitudinal study of males with very detailed information on a variety of occupational and other health risks and outcomes Clear value of retaining and maintaining materials to study –Health effects of herbicides/dioxin in veterans –Other aspects of military health and environmental and occupational exposures –Chronic disease risks –Normal aging
Consent to Use Records and Materials Response Comparison N (%) Ranch Hand N (%) Total N (%) AO & Health AO only Do not use Other Total 1,138 (96.9) 23 (2.0) 11 (0.9) 2 (0.2) 1, (94.1) 32 (4.1) 11 (1.4) 3 (0.4) 777 1,869 (95.8) 55 (2.8) 22 (1.1) 5 (0.3) 1,951
Making Data and Materials Available to Researchers Separately consider –A. Logistics and costs of maintenance of materials –B. Costs of further research using these materials If data and material were available to researchers, NIH and other research funders could support research using it through established programs