Relationship of pain behavior to disease activity and health status in rheumatoid arthritis.

The purpose of the study was to investigate the contributions of disease activity, health status, and self-efficacy to the pain behavior exhibited by patients with rheumatoid arthritis. Measures included the Arthritis Impact Measurement Scales, the Arthritis Self-Efficacy Scale, a visual analogue scale for pain, and the McGill Pain Questionnaire. Joint counts and ratings of pain behavior also were obtained. All measures were collected at both baseline and 6 months. Hierarchical multiple regression analyses revealed that disease activity, as measured by joint count, was significantly related to a modified pain behavior index at both time intervals. With joint count entered into the regression model, no other variable consistently increased the predictive accuracy of the model. There were no significant correlations between the modified pain behavior index and either the visual analogue scale for pain or the McGill Pain Questionnaire scores. The results suggest that pain behavior in male rheumatoid arthritis patients is more closely related to disease activity than to self-reported pain, health status, or perceived self-efficacy.