Development of the QuickDASH: Comparison of Three Item-Reduction Approaches

• Published in: Journal of bone and joint surgery. American volume 2005-05, Vol.87 (5), p.1038-1046
• Main Authors: Beaton, Dorcas E, Wright, James G, Katz, Jeffrey N
• Format: Article
• Language: English
• Subjects: Arm; Biological and medical sciences; Diseases of the osteoarticular system; Hand; Health Status Indicators; Humans; Medical sciences; Musculoskeletal Diseases; Orthopedic surgery; Outcome Assessment (Health Care); Psychometrics; Reproducibility of Results; Sensitivity and Specificity; Shoulder; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/JBJS.D.02060

BackgroundThe purpose of this study was to develop a short, reliable, and valid measure of physical function and symptoms related to upper-limb musculoskeletal disorders by shortening the full, thirty-item DASH (Disabilities of the Arm, Shoulder and Hand) Outcome Measure.MethodsThree item-reduction techniques were used on the cross-sectional field-testing data derived from a study of 407 patients with various upper-limb conditions. These techniques were the concept-retention method, the equidiscriminative item-total correlation, and the item response theory (Rasch modeling). Three eleven-item scales were created. Data from a longitudinal cohort study in which the DASH questionnaire was administered to 200 patients with shoulder and wrist/hand disorders were then used to assess the reliability (Cronbach alpha and test-retest reliability) and validity (cross-sectional and longitudinal construct) of the three scales. Results were compared with those derived with the full DASH.ResultsThe three versions were comparable with regard to their measurement properties. All had a Cronbach alpha of ≥0.92 and an intraclass correlation coefficient of ≥0.94. Evidence of construct validity was established (r ≥ 0.64 with single-item indices of pain and function). The concept-retention method, the most subjective of the approaches to item reduction, ranked highest in terms of its similarity to the original DASH.ConclusionsThe concept-retention version is named the QuickDASH. It contains eleven items and is similar with regard to scores and properties to the full DASH. A comparison of item-reduction approaches suggested that the retention of clinically sensible and important content produced a comparable, if not slightly better, instrument than did more statistically driven approaches.Clinical RelevanceThe QuickDASH is a more efficient version of the DASH outcome measure that appears to retain its measurement properties.