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2 Identifying Conditions for Study

As described in Chapter 1, the health of Gulf War veterans has been studied from many perspectives. Numerous organizations and individuals have sought answers to address the complex issues surrounding the Gulf War, but questions remain. Some of the questions concern how to define the kinds of health problems veterans are experiencing and to what extent already-validated treatments may exist for these problems.

Although the terms “Gulf War illness” or “Persian Gulf syndrome” have been used to describe the health problems of ill veterans returning from the Gulf War, no study has been able to identify a single accepted condition, diagnosis, group of diagnoses, or etiology that explains the symptoms experienced by these veterans (IOM 1999a). Numerous studies have examined data regarding veterans and their symptoms (Perconte et al., 1993; Southwick et al. 1993; Stretch et al. 1995; Sostek et al. 1996; Iowa Persian Gulf Study Group 1997; Pierce 1997; Fukuda et al. 1998; Goss Gilroy 1998; Wolfe et al. 1998; IOM 1999a; DVA 1999; Kang et al. 2000). While clusters of symptoms including fatigue, joint and muscle pain, headache, memory loss, depression, anxiety, respiratory problems, and diarrhea have been noted, no one group of patients has all of these symptoms nor even a majority of them. Many of the studies have shown that Gulf War veterans report a higher level of symptoms and self-reported illness, as well as functional impairment than do nondeployed veterans; however, none has been able to link these health problems to a specific condition, etiological agent, or exposure. To do so involves a long and complex process.

The process for determining whether patients have a new unique



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Page 23 2 Identifying Conditions for Study As described in Chapter 1, the health of Gulf War veterans has been studied from many perspectives. Numerous organizations and individuals have sought answers to address the complex issues surrounding the Gulf War, but questions remain. Some of the questions concern how to define the kinds of health problems veterans are experiencing and to what extent already-validated treatments may exist for these problems. Although the terms “Gulf War illness” or “Persian Gulf syndrome” have been used to describe the health problems of ill veterans returning from the Gulf War, no study has been able to identify a single accepted condition, diagnosis, group of diagnoses, or etiology that explains the symptoms experienced by these veterans (IOM 1999a). Numerous studies have examined data regarding veterans and their symptoms (Perconte et al., 1993; Southwick et al. 1993; Stretch et al. 1995; Sostek et al. 1996; Iowa Persian Gulf Study Group 1997; Pierce 1997; Fukuda et al. 1998; Goss Gilroy 1998; Wolfe et al. 1998; IOM 1999a; DVA 1999; Kang et al. 2000). While clusters of symptoms including fatigue, joint and muscle pain, headache, memory loss, depression, anxiety, respiratory problems, and diarrhea have been noted, no one group of patients has all of these symptoms nor even a majority of them. Many of the studies have shown that Gulf War veterans report a higher level of symptoms and self-reported illness, as well as functional impairment than do nondeployed veterans; however, none has been able to link these health problems to a specific condition, etiological agent, or exposure. To do so involves a long and complex process. The process for determining whether patients have a new unique

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Page 24clinical entity distinct from all other established diagnoses, while not clearcut, does have several recognized steps. Generally, the process begins with the identification of patients who are experiencing symptoms that do not coincide with established recognizable diagnoses. An attempt is then made to determine whether there are patterns or clusters of symptoms that are common to a wide group of patients. If such patterns are detected, experts are able to develop a “case definition.” A case definition strives to contain not only common symptoms but a mix of clinical, laboratory, and epidemiological criteria. This case definition is used to identify a new patient population that is distinct from other patient populations with recognized syndromes, conditions, or diagnoses (IOM 2000). Much of the published literature on the health of Gulf War veterans has searched for an etiology or tried to prove causality in defining a specific disease or syndrome in ill Gulf War veterans. A disease can be characterized as having (1) common symptoms or signs and/or laboratory findings and (2) a defined etiology or pathophysiology with identifiable abnormalities in body structure or function. Syndromes or conditions also have common symptoms and signs, but the etiology and pathophysiology of the syndrome are often unknown. The patient's illness is defined by common symptoms or physical findings and therapy becomes symptom based. Therapy is standardized to that group of patients with common symptoms, and treatment effectiveness is often measured by improvement in quality of life indicators. For patients who have symptoms or groups of symptoms that cannot be linked to a specific syndrome or disease, and where no group of patients has the same group of symptoms (medically unexplained physical symptoms or medically unexplained illness), approaches to treatment are more difficult. Because there has been no single identifiable disease to treat, it has not been possible to develop a uniform approach to health interventions in the Gulf War veteran population. The Department of Defense (DoD) is implementing a longitudinal study of health status that may yield useful information in planning for the future care of veterans of conflict; however, physicians treating Gulf War veterans need guidance now on treatment, and patients need to feel there is an approach to treatment that results in improved health. The committee was asked to identify illnesses and conditions present among Gulf War veterans, to identify valid models of treatment for such illnesses to the extent they exist, and to identify new approaches, theories, or research on management of these conditions if validated treatment models are not available. To accomplish this, the committee examined the most common symptoms reported by Gulf War veterans and grouped them into established and accepted symptom-based conditions. This approach is supported by a number of well-done population studies (Iowa Persian Gulf Study Group 1997; Goss Gilroy 1998; Unwin et al. 1999).

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Page 25 In addition to testimony from veterans' groups, patients, and their families regarding problems they have encountered (see Appendix B for details), the committee reviewed published studies that examined symptoms and conditions reported in Gulf War veterans. Symptom reports from 10 surveys are displayed in Table 2-1. Other symptoms reported include back pain, wheezing, swelling in joints, loss of strength, blurred vision, sensitivity to chemicals, slow healing, impotence, painful intercourse, and burning semen. Most Gulf War veterans experiencing one or more of these symptoms have readily identifiable medical conditions. However, about 20% of symptomatic veterans examined in the VA and DoD registries report multiple symptoms for which no readily identifiable diagnosis exists. Symptoms reported correspond closely to symptoms experienced by people in other than veteran populations who have recognized diagnoses of unknown etiology. Symptoms experienced by Gulf War veterans have a significant degree of overlap with symptoms of patients diagnosed with these conditions, such as fibromyalgia (joint pain, sleep disturbances, fatigue), chronic fatigue syndrome (fatigue, headache, cognitive dysfunction), depression (fatigue, loss of memory and other general symptoms, cognitive dysfunction, and sleep disturbances), and irritable bowel syndrome (diarrhea and other gastrointestinal symptoms, abdominal pain, nausea, and vomiting). The committee decided that it would examine treatments for these recognized diagnoses of unknown etiology to determine what might be learned and borrowed from these conditions to apply to the treatment of Gulf War veterans. Headache and panic disorder were included in the report because they also involve symptoms similar to those reported by Gulf War veterans. Posttraumatic stress disorder (PTSD) was included because of its increased prevalence in this as well as other veteran populations. 1 There are also a number of patients who experience symptoms that do not fall into these defined diagnostic categories. The committee considered two alternative approaches to evaluating treatments for patients with unexplained symptoms: (1) the dimensional approach and (2) the categorical approach. The dimensional approach posits that a substantial overlap exists between the individual syndromes; that is, unexplained illness occurs on a continuum of the population extending from individuals with symptoms to those without symptoms and the similarities between conditions out 1 The committee acknowledges the VA's expertise in the treatment of PTSD but includes the diagnosis here for the sake of completeness.

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Page 26 TABLE 2-1 Symptoms Reported in Gulf War Veterans by Study Conducted Reference Symptom 1 2 3 4 5 6 7 8 9 10 Fatigue + + + + + + + Skin rash/irritation + + + + + + + + + + Headache + + + + + + + + + Muscle/joint pain + + + + + + + + Joint stiffness + + + Loss of memory and other general symptoms + + + + + + Cognitive dysfunction + + + + + + Shortness of breath + + + + + + + Sleep disturbance + + + + + + + + + Diarrhea and other gastrointestinal symptoms + + + + + + + Abdominal pain + + + + + + + + Nausea and vomiting + + + + + + Chest pain/tightness + + + + Choking sensation + + + Cough + + + + +

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Page 27 Heart flutters/irregular beats + + + + Genitourinary problems + + + + Numbness/tingling + + + + Dizziness/blackouts + + + + + Sinus trouble + + + + Symptoms of cold, flu, hay fever, allergies + + + + + + Depression/irritability + + + + + + Anxiety + + + + Unintentional weight change + + + + + + Hair loss + + Mouth/gum problems + + + References: 1. Kang et al. 2000 2. DVA 1999 3. IOM 1998b 4. Fukuda et al. 1998 5. Coker et al. 1999 6. Stretch et al. 1995 7. CDC, MMWR 1995 8. Wolfe et al. 1998 9. Pierce 1997 10. Proctor et al. 1998

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Page 28weigh the differences (Wessely et al. 1999). Wessely and colleagues suggested that rather than approach treatment of these conditions as separate entities, a more appropriate position would be a symptom-based approach that puts “an end to the belief that each ‘different' syndrome requires its own particular subspecialist” (p. 939). Treatments would be evaluated based on symptoms rather than diagnostic categories. The categorical approach uses defined separate clinical syndromes or diagnostic entities that are based on symptoms (e.g., chronic fatigue syndrome, fibromyalgia, irritable bowel syndrome), acknowledging they may have overlapping symptoms. Because research on the efficacy and effectiveness of treatments has been diagnosis specific, the committee, of necessity, has followed the categorical approach in evaluating treatments and has grouped symptoms experienced by Gulf War veterans into the following diagnostic categories that have been the subject of efficacy or effectiveness research: Chronic fatigue syndrome Depression Fibromyalgia Headache Irritable bowel syndrome Panic disorder Posttraumatic stress disorder As with all symptom-based conditions, however, there are veterans who have symptoms that do not fit into any of the above categories. To address these patients' illnesses, the committee has taken a dual approach. A general approach that can be used with all patients is outlined in Chapter 4, while Chapter 5 describes a more specific approach for addressing the treatment of veterans with specific conditions. Future efforts to determine treatment effectiveness could include outcomes research on treatment for those with symptoms but no diagnosis. Veterans with common symptoms could be evaluated using specific interventions to study response and measure outcomes in order to add to the body of therapeutics that might improve the health of ill Gulf War veterans. One could use the study approaches described in Chapter 3 to assess the effectiveness of other therapies or interventions in addressing these other symptom complexes. It is hoped that the recommendations that follow in the chapters of this report will provide a more uniform approach to the diagnosis and treatment of difficult-to-diagnose and ill-defined conditions such as chronic fatigue syndrome and fibromyalgia. To the extent that effective treatments of specific symptom complexes and diagnoses are implemented, it is hoped that veterans will receive care that increases their

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Page 29overall quality of life, regardless of where they live or at what treatment facility they receive their medical care. Chapter 3 discusses the difference between treatment efficacy and treatment effectiveness, describes study approaches that can be used for both, and recommends an approach to use for the conduct of future studies of treatment effectiveness.

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