Pain measurement in arthritis.

Objective. This paper reviews the major pain measurement methods used with adult patients with rheumatoid arthritis, osteoarthritis, and fibromyalgia. Methods and Results. The most frequently used measures are numerical and verbal rating (category) scales of pain intensity and affect. However, visual analogue scales and composite measures are preferable to category scales because they may be subjected to parametric statistical analyses and may be associated with greater sensitivity to treatment-related changes over time. Measurement of overt motor behaviors and pain threshold levels provides important information that cannot be assessed with rating scales. It also allows one to determine whether there are discrepancies between patients' ratings of their pain experiences and their behaviors. Measurement of psychophysiologic parameters are used to understand better how markers of immune system activity may mediate the relationships between psychological and environmental factors and patients' pain experiences. Conclusions. It is necessary to use multiple pain measurement methods for clinical and research purposes. These should include at least two measures of pain intensity and affect as well as a measure of pain behavior.