Quantitative pain assessment for routine care of rheumatoid arthritis patients, using a pain scale based on activities of daily living and a visual analog pain scale

Abstract
Pain was assessed quantitatively as a component of routine visits of 385 outpatients with rheumatoid arthritis, using a pain scale based on activities of daily living (ADL) and a visual analog scale. The ADL pain scale met psychometric criteria for validity and reliability. Scores on the 2 pain scales were correlated significantly with one another and with other measures of disease status, including joint count, grip strength, walking time, button test, morning stiffness, erythrocyte sedimentation rate, global self-assessment, ADL difficulty, and ADL dissatisfaction scales. Correlations of ADL pain scale scores with other measures were higher than were correlations of visual analog scale scores with other measures, in both unadjusted and adjusted analyses. Significantly more patients completed the ADL pain scale without assistance than the number of those who completed the visual analog pain scale. The ADL pain scale was more sensitive to problems in ADL than were the ADL scales for difficulty and dissatisfaction. The ADL and visual analog pain scales appear to provide useful data for quantitative assessment of pain in the routine care of rheumatoid arthritis patients.