Evaluative properties of measures used to assess patients with lateral epicondylitis at the elbow

This study's purpose was to examine the ability of five outcome measures to assess valid change over time in patients with lateral epicondylitis at the elbow. The measures, a pain free function questionnaire, pain visual analog scale, function visual analog scale, pain free grip strength, and maximum grip strength, were assessed prior to treatment and weekly over a four week period in 40 patients. Two additional ratings were also obtained. Patients were asked to make a global assessment of their change on a five point scale and an independent assessor rated each patient's response at the end of treatment (i.e., success or failure). Indexes of responsiveness to change and the validity of change were calculated. The results indicate that the most valid measures of change are the pain free function questionnaire and pain free grip strength. Maximum grip strength appears to be the least valid measure.