Disability associated with pain--a clinical approximation of the mediating effect of belief and attitudes.

Our objective was to test the hypothesis that pain beliefs are mediators of disability in a population of workers with chronic pain. A cross-sectional study composed of 115 workers with work-related musculoskeletal disorders (WRMD) whose symptoms appeared 6 months before the beginning of the study was conducted. Outcome measures included questionnaires on pain, pain beliefs, physical disability, and depression. Almost half of the sample (42%) reported moderate pain; the mean disability score was 11.5. Assessment of pain beliefs revealed that only the emotion domain was "more adaptive." Thirty-eight workers presented depressive symptoms (33%), with a mean score of 18. A multiple linear regression analysis identified the best predictors associated with disability in sample. The variables that remained in the model were intensity of pain, domains solicitude, and disability from the survey of pain attitudes, physical disability, and depression. Results showed that pain beliefs are partial mediators of the relation between chronic pain and disability. When depression was added to the model, there was a significant increase in the explanation of disability variance, indicating that this variable is an important factor associated with functional limitation. Disability associated with chronic pain is a multidimensional experience, affected by the interaction of social and psychological factors.