An Institute of Medicine committee could not reach consensus on a single definition of Gulf War illness and recommended in a new report that clinicians and researchers at least narrow it down to two definitions.
That’s the preferred term – Gulf War illness – for a slew of health problems that occur at a higher rate in the approximately 697,000 U.S. veterans who served in the 1990-1991 Gulf War than in other veterans, the committee said. Gulf War illness is widely used and is more accurate than other terms used over the years for the same problems, including Gulf War syndrome, chronic multisystem illness, unexplained illness, medically unexplained symptoms, and medically unexplained physical symptoms, the report stated.
The Institute of Medicine (IOM) drafted a committee of 16 experts at the request of the Department of Veterans Affairs to try to develop a case definition for what's now called Gulf War illness in order to help standardize diagnosis, inclusion in research studies, and treatments. The committee's 120-page report, "Chronic Multisymptom Illness in Gulf War Veterans: Case Definitions Reexamined," is available on the IOM website.
Unable to find validation for one definition because of methodologic limitations in the studies, the committee recommended using either a broader definition from the Centers for Disease Control and Prevention (CDC) or a more restrictive one from studies of Kansas veterans, depending on the situation. Between the two of them, the definitions capture the most common symptoms of Gulf War illness and provide a framework for more focused research and treatment, the report said.
The committee found 2,033 articles in the literature focused on Gulf War illness symptoms and closely reviewed 718 of them. It found no objective diagnostic criteria but saw cumulative evidence that Gulf War illness is real. Fatigue, pain, and neurocognitive, gastrointestinal, respiratory, and/or dermatologic symptoms were reported with higher frequency in Gulf War veterans than in veterans of the same era who had not been deployed or were deployed elsewhere.
To identify the illness in a Gulf War veteran, the CDC definition requires one or more symptoms in at least two of the following categories: fatigue, pain, or mood and cognition. The Kansas definition requires symptoms in at least three of the following domains: fatigue or sleep, pain, neurologic or cognitive or mood symptoms, gastrointestinal symptoms, respiratory symptoms, and skin symptoms.
The CDC definition identified the illness in 29%-60% of Gulf War veterans, depending on the population studied. The Kansas definition identified the illness in 34% of Kansas veterans of the Gulf War.
The reason the committee couldn’t compile a single case definition is that the studies in the literature do not report on key features of the illness including onset, duration, severity, frequency of symptoms, and exclusionary criteria. The Department of Veterans Affairs should boost efforts to collect these kinds of data, conduct earlier in-depth assessments after deployment when unexpected complaints occur, and track troops’ exposures to vaccinations, drugs, and environmental factors, the report recommends.
The name Gulf War illness won out over Gulf War syndrome because "syndrome" indicates a new group of signs and symptoms, while the types and patterns of symptoms in this illness commonly are seen with other illnesses. The committee rejected "chronic multisymptom illness" because the phrase is not specific to Gulf War veterans.
The committee included experts in clinical medicine, toxicology, psychiatry, neurology, gastroenterology, epidemiology, sociology, psychometrics, biostatistics, occupational medicine, and basic science.
The report does not include potential disclosures of conflicts of interest.
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