(HealthDay News) – For patients with fibromyalgia, spatial extent of pain, pain aftersensation, and negative mood account for approximately one-third of the variance in clinical pain, but sleep measures do not significantly predict pain.

To investigate whether measures of sleep would improve prediction of a clinical pain model, Ryan J. Anderson, from the University of Florida in Gainesville, and colleagues conducted a study of 74 adults with fibromyalgia. Usual pain, spatial extent of pain, negative mood, and pain aftersensation were measured. Objective and subjective sleep measures and nightly wake time were also obtained during a 14-day period.

The researchers found that increased spatial extent, elevated aftersensation ratings, and increased negative mood explained 36% of the variation in clinical pain. Clinical pain was not significantly predicted by any of the sleep variables.

“The current study confirmed that a model of aftersensation, sum of local pain areas, and negative mood is a strong predictor of clinical pain intensity in fibromyalgia,” the authors write. “The data did not support the hypothesis that measures of sleep would increase the predictive ability of the model.”

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