Dash and Boston questionnaire assessment of carpal tunnel syndrome outcome: what is the responsiveness of an outcome questionnaire?

This prospective study evaluates if the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire is an adequately responsive outcome measure in carpal tunnel syndrome by comparing it with the disease-specific Boston questionnaire (BQ). To measure responsiveness (sensitivity to clinical change), 57 patients with a clinical diagnosis of carpal tunnel syndrome completed the DASH and BQ preoperatively and again 3 months after open carpal tunnel decompression. A second group of 31 patients completed the questionnaires in the outpatient clinic and again 2 weeks later to assess test-retest reliability. The time to complete all questionnaires was recorded. Responsiveness of the DASH is comparable with the BQ with standardized response means of 0.66, 1.07 and 0.62 for the DASH, BQ-symptoms and BQ-function, respectively. Test-retest data show both questionnaires are reliable. Mean times to complete questionnaires were 6.8minutes (DASH) and 5.6minutes (BQ). This study concludes that the DASH questionnaire is a reliable, responsive and practical outcome instrument in carpal tunnel syndrome.