Visual analogue scales as a measure of pain in arthritis: a study of overall pain and pain in individual joints at rest and on movement.

Visual analogue scales (VAS) for overall and individual joint pain at rest and on movement were completed by 105 patients with polyarthritis as part of a study of the relationship between overall pain and pain in individual joints. Not all subjects recorded pain on a conventional VAS although all had at least 2 painful joints on movement. At best only 25% of the variance in overall pain was explained by pain in individual joints. Our findings suggest that conventional overall measures of pain in arthritis may neglect aspects of pain experience which relate to individual joints and to pain on movement.