Disposition of the

Air Force Health Study

Michael A. Stoto, PhD

Institute of MedicineApril 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

1960 1970 1980 1990 2000 2010

Protocol DevelopmentPhysical 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

157

4540

16,600

Ground troop veterans in AOVS

Ranch Hand veterans

Occupational exposures

Seveso, Italy population

355

0 20 40 60 80 100 1000 10,000

Numbers of Veterans Physically Examined

Year Ranch Hand Comparison Total

1982

1985

1987

1992

1997

2002

1,045

1,016

995

952

869

777

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

Item Number

Biological specimensX raysPhysical examinationsQuestionnairesDeath recordsViable conceptionsNonviable conceptions

74,57719,59413,17720,645

2,8196,8011,490

Knowledgeable Staff

Research Results

Study Disposition• Veterans Benefits Act of 2003 (PL108-

183): 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)

1,174

731 (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