Arthritis is the most common form of joint disease. Several powerful risk factors are major trauma, repetitive joint use, and age. Arthritis is diagnosed according to a combination of clinical features and radiographic findings. Arthralgia, which is a self-reported symptom of arthritis, refers to painful joints. In the absence of other clinical features and radiographic findings, arthralgias are not necessarily diagnostic of arthritis. Some disorders such as fibromyalgia are considered separately in this report. Reports of musculoskeletal symptoms, such as lower back pain (lumbago), muscle stiffness, and joint stiffness, which have not been diagnosed as a medical condition, are discussed in the section on multisymptom illness. Primary studies of musculoskeletal diseases are summarized in Table 4-11.
Arthralgias were one of 12 primary health outcome measures studied by Eisen and colleagues (2005). They conducted medical evaluations in phase III of VA’s nationally representative, population-based study of Gulf War Veterans. From 1999-2001, 1061 deployed and 1128 nondeployed veterans were evaluated. They had been randomly selected from 11,441 deployed and 9476 nondeployed veterans who had participated in the phase I questionnaire in 1995 (Kang et al., 2000). Researchers were blinded to deployment status. Arthralgias were defined as persistent and clinically significant bone or joint symptoms with or without joint effusion, and treatment with anti-inflammatory agents, narcotic pain medications, or nonnarcotic pain medications. There was no significant difference in arthralgias between deployed and nondeployed veterans (OR 1.15, 95% CI 0.70-1.89). One study limitation was that despite three recruitment waves, the participation rate in the Eisen et al. (2005) study was low: only 53% of Gulf War veterans and 39% of nondeployed veterans participated. To determine nonparticipation bias, the authors obtained previously collected findings on participants and nonparticipants from the DMDC and gathered sociodemographic and self-reported health findings from the 1995 VA study (Kang et al., 2000). Both deployed and nondeployed participants were more likely than nonparticipants to report arthritis of any kind.
Two other studies examined differences in prevalence of arthritis, but they relied on self-reporting. Kang et al. (2000), using a stratified random-sampling method, compared data from the DMDC on 693,826 Gulf War veterans and 800,680 nondeployed veterans, and asked about arthritis as a self-reported condition. They found a significant difference in such reporting between deployed and nondeployed veterans (22.5% vs 16.7%, rate difference of 5.87, 95% CI 5.74-6.00). Gray et al. (2002) looked at 3831 Gulf War deployed veterans, 4933 veterans deployed elsewhere, and 3104 nondeployed Seabees. The authors found increased reporting of arthritis among Gulf War than deployed compared with Seabees deployed elsewhere (5.87% vs 4.42%). The latter, in turn, were similar to other nondeployed Seabees (4.42% vs 4.38%). The OR for Gulf War veterans versus veterans deployed elsewhere was 1.44 (95% CI 1.17-1.76), and that for Gulf War deployed versus nondeployed veterans was 1.63 (95% CI 1.29-2.08).