2.04). The authors commented on the potential effects of the survey procedures, response bias, symptom measurement, and confounding in each study. They noted that although the methodologic quality of the 20 studies varied considerably, all but one of the studies found more self-reports of pain in Gulf War-deployed than in nondeployed veterans.
The DSM-IV also has a category of somatoform disorders that includes pain disorder that has been studied in some veterans. Toomey et al. (2007) found that Gulf War veterans had substantially more pain disorders, as diagnosed with the CIDI using the DSM-IV criteria, than did nondeployed veterans (OR 91.66, 95% CI 10.52-798.21). Ikin et al. (2004) interviewed a random sample of Australian Gulf War veterans after the war to determine the prevalence of various psychiatric disorders using the CIDI. They found that deployed veterans (n = 1381) were no more likely than nondeployed veterans (n = 1377) to have any somatic disorder (OR 2.6, 95% CI 1.0-6.3) but not pain disorder (OR 1.4, 95% CI 0.2-16.4). ORs were adjusted for service type, rank, and age; for any somatic disorder, the OR was also adjusted for education and marital status.
Combat exposure has been linked to somatoform pain disorder (O’Toole et al. 1996a). The ORs for a current (1-month) diagnosis of somatoform pain disorder in Australian Vietnam veterans, based on the DIS, compared with each quartile increase in combat exposure (based on a 21-item combat index) were 1.00, 1.76, 3.07, and 5.08 (p < 0.0005); ORs for lifetime somatoform pain disorder and increasing combat exposure were 1.00, 1.05, 1.88, and 2.47 (p < 0.001).
Although chronic pain is common in deployed veterans, veterans with PTSD are at particular risk. Chronic pain is one of the most commonly reported physical complaints of people (veterans and nonveterans) who have PTSD (McFarlane et al. 1994). And PTSD is common in people who have chronic pain as the result of an accident or trauma (Otis et al. 2003). Several studies that have examined the relationship between PTSD and chronic pain in veterans are discussed below.
Asmundson et al. (2004) reported on a sample of 221 female veterans who used a VA Health Center clinic in 1998-1999 for general health purposes. The women were identified as having PTSD on the basis of responses to a mailed questionnaire that included the PTSD Checklist-Civilian Version, the SF-36, and two additional questions about pain in the preceding 6 months. Female veterans with PTSD reported significantly greater pain—including bodily pain, pain interference, severe headache or migraine, and back pain—than did those without PTSD.
Beckham et al. (1997) investigated patterns of chronic pain in Vietnam veterans with PTSD. Of 129 combat veterans with PTSD, 80% reported chronic pain as determined by the Pain Disability Index, the McGill Pain Questionnaire, the Visual Analog Scale, and a pain drawing; PTSD was diagnosed with the CAPS. Combat veterans with PTSD and chronic pain reported significantly higher somatization, as measured by the hypochondriasis and hysteria subscales of the Minnesota Multiphasic Personality Inventory-2, than did combat veterans with PTSD but without chronic pain. In the sample of 103 veterans with PTSD and chronic pain, Minnesota Multiphasic Personality Inventory-2 hypochondriasis scores and PTSD symptoms from the re-experiencing symptom cluster were significantly related to pain disability, overall pain index, and current pain level.