formation from actual differences in the frequency of exposures. As a result, findings from these studies may be spurious or equivocal. Fifth and last, classifying the veterans' symptoms and identifying the illnesses have been difficult. From the outset, the symptoms reported have been varied and difficult to classify into one or more distinct groups. Moreover, several different diagnoses might provide plausible explanations for some of the specific health complaints. It has thus been difficult to develop one or more working case definitions to describe veterans' undiagnosed complaints.

Given these methodological limitations which are faced in the epidemiological studies and because of the numbers of veterans who experienced illnesses that might be related to their Gulf war service, we recommended in our report that the Secretary of Defense, with the Secretary of the VA, give greater priority to research on effective treatment for ill veterans and on low-level exposures to chemicals and other agents, as well as their interactive effects, and less priority to further epidemiological studies.

Mr. Chairman, that concludes my prepared remarks. I will be happy to answer any questions you may have.

[The prepared statement of Ms. Heivilin follows:]

Mr. Chairman and Members of the Subcommittee:

I am pleased to be here today to discuss our evaluation of the

federal strategy to research Gulf War illnesses.

We reported our

findings on this strategy in June 1997 as part of our response to a congressional mandate regarding the government's clinical care and medical research programs relating to illnesses suffered by Gulf War veterans.1

I will first summarize our findings and provide

some background information on the government's research program before giving you the details on our findings.

RESULTS IN BRIEF

In short, we found that

(1) the government was not proactive in researching Gulf War

illnesses;

(2)

the government's early research emphasized stress as a cause for Gulf War veterans' illnesses and gave other hypotheses, such as multiple chemical sensitivity, little attention;

1Gulf War Illnesses: Improved Monitoring of Clinical Progress and Reexamination of Research Emphasis Are Needed (GAO/NSIAD-97-163, June 23, 1997).

(3)

in contrast, the private sector pursued research on the health effects of low-level exposures to certain chemical warfare agents or industrial chemical compounds;

(4)

government research used an epidemiological approach, but
little research on treatment was funded; and

(5)

most of the ongoing epidemiological research focusing on the prevalence or causes of Gulf War-related illnesses will not provide conclusive answers, particularly in identifying risk factors or potential causes due to formidable methodological and data problems.

BACKGROUND

U.S. troops were reportedly exposed before, during, and after the Gulf War to a variety of potentially hazardous substances. These substances include decontaminating and protective compounds used without proper safeguards (particularly decontaminating solution 2, or DS2, and chemical agent resistant coating); diesel fuel used as a sand suppressant in and around encampments, fuel oil used to burn human waste; fuel in shower water; and leaded vehicle exhaust used to dry sleeping bags. Other potential hazards included infectious diseases (most prominently leishmaniasis, a parasitic infection); pyridostigmine bromide and vaccines (to protect against chemical and biological weapons); depleted uranium (contained in certain

ammunition and in residues from the use of this ammunition); pesticides and insect repellents, chemical and biological warfare agents; and compounds and particulate matter contained in the extensive smoke from the oil-well fires at the end of the war. Over 100,000 of the approximately 700,000 Gulf War veterans have participated in health examination programs that the Department of Defense (DOD) and the Department of Veterans Affairs (VA)

established between 1992 and 1994. Of those veterans examined by DOD and VA, nearly 90 percent have reported a wide array of health complaints and disabling conditions, including fatigue, muscle and joint pain, gastrointestinal complaints, headaches, depression, neurologic and neurocognitive impairments, memory loss, shortness of breath, and sleep disturbances. Some of the veterans fear that they are suffering from chronic disabling conditions because of exposure during the war to substances with known or suspected health effects.

The federal government, primarily through DOD and VA, has sponsored a variety of research on Gulf War veterans' illnesses. DOD's research is one component of a broader agenda coordinated under the aegis of the Persian Gulf Veterans' Coordinating Board (PGVCB), which comprises the Secretaries of the Department of Health and Human Services, VA, and DOD. The details of this agenda are described in the PGVCB publication entitled A Working Plan for

Research on Persian Gulf Veterans' Illnesses. This agenda was developed in response to an Institute of Medicine conclusion that the DOD and VA should determine specific research questions that need to be answered and design epidemiologic research to these questions. Accordingly, most of the research sponsored under this agenda is characterized by PGVCB as epidemiological.

The objectives of epidemiologic research are to determine the extent of diseases and illness in the population or subpopulations, the causes of disease and its modes of transmission, the natural history of disease, and the basis for developing preventive strategies or interventions.'

To conduct such research,

investigators must follow a few basic generally accepted principles.

First, they must specify diagnostic criteria to (1) reliably determine who has the disease or condition being studied and who does not and (2) select appropriate controls (people who do not have the disease or condition).

Second, the investigators must have valid and reliable methods of collecting data on the past exposure(s) of those in the study and possible factors that may have caused the symptoms. The need for

2A Working Plan for Research on Persian Gulf Veterans' Illnesses, (First Revision), Department of Veterans Affairs, November 1996. A. M. Lilienfeld and D. E. Lilienfeld, Foundations of Epidemiology (New York: Oxford University Press, 1980).