Relationship between performance validity testing, disability status, and somatic complaints in patients with fibromyalgia.

Fibromyalgia is a chronic pain-related disorder that typically includes cognitive complaints as well as non-specific somatic complaints, such as fatigue and sleep disturbance (Wolfe et al., 2010). Fibromyalgia has also been shown to be associated with a high rate of failure on performance validity testing (PVT), which has not been examined with respect to other self-reported symptoms that are now part of the diagnostic criteria for the disorder. We evaluated 85 patients with fibromyalgia who completed objective measures of pain, sleep, and fatigue along with symptom validity measures (Word Memory Test or Test of Memory Malingering and Reliable Digit Span). Three groups were formed based on effort testing: Two PVTs Failed, One PVT Failed, and No PVTs Failed. We also formed three groups based on disability status: On Disability, Applying for Disability, and Not on Disability. A total of 37% of the patients failed one or both PVTs. PVT group analyses were significant for daily pain, weekly pain, and sleep, but not fatigue. Disability status analyses were significant for daily pain, weekly pain, and fatigue, but not sleep. The implication of this study is that PVT performance and disability status are associated with exaggeration of non-cognitive symptoms such as pain, sleep, and fatigue in persons with fibromyalgia. This study reinforces the importance of effort testing when working with medical populations.