The aim of this prospective single-group observational study was to determine the minimal clinically significant difference (MCID) for the Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH) and its shortened version (QuickDASH) in patients with upper-limb musculoskeletal disorders, using a triangulation of distribution- and anchor-based approaches. Meaningful threshold change values of outcome tools are very important for the clinical decision-making process. Methods DASH and QuickDASH were administered to 255 patients (mean age 49±15 years SD; 156 females) prior to and following a physical therapy program. The external anchor, administered after the program, was a 7-point Global Rating of Change Scale. Results The test-retest reliability of DASH and QuickDASH was high (ICC2,1 = 0.93 and 0.91, respectively; n= 30). The minimum detectable change at 90% confidence level (MDC90) was 10.81 points for DASH and 12.85 points for QuickDASH. After triangulation of these results with those of mean change approach and Receiver Operating Characteristic (ROC) curve analysis, the following MCID values were selected: 10.83 points for DASH (sensitivity 82%; specificity 74%) and 15.91 points for QuickDASH (sensitivity 79%; specificity 75%). After intensive treatment, the MCID threshold was reached/surpassed by 61% of subjects using DASH and 57% using QuickDASH.
The authors concluded that their MCIDs for DASH (10.83 points) and QuickDASH (15.91 points) might represent the lower boundary for a small range of MCID values (reasonably useful for different populations and contextual characteristics), where the upper boundary represented by the 15 points for DASH and 20 points for QuickDASH proposed by the official DASH website.