Responsiveness of the Korean Version of the Disabilities of the Arm, Shoulder and Hand Questionnaire (K-DASH) after Carpal Tunnel Release

BACKGROUND The Korean version of the Disability of the Arm, Shoulder and Hand Questionnaire (K-DASH) was recently validated, but its responsiveness, which is the degree to which an instrument is sensitive to change, has not been thoroughly evaluated in a specific condition in Koreans. We evaluated the responsiveness of the K-DASH in a homogenous cohort of patients with carpal tunnel syndrome (CTS) and we compared it with that of the disease-specific Carpal Tunnel Questionnaire (CTQ). METHODS Fifty-six patients with CTS prospectively completed the K-DASH and CTQ before and 6 months after surgery. The responsiveness statistics were assessed for both the K-DASH and CTQ by using the standardized response mean (SRM) and the effect size (ES). Pearson correlation coefficients were calculated between the K-DASH and CTQ. RESULTS The SRM and ES of the K-DASH were all 0.8. The SRM of the symptom and function part of the CTQ was 1.5 and 1.1, and the ES was 1.5 and 1.1, respectively. The K-DASH had moderate correlations with the symptom and function parts of the CTQs, but the postoperative K-DASH had a weak correlation with the symptom part of the postoperative CTQ. CONCLUSIONS The K-DASH was found to have a large degree of responsiveness (SRM, ES ≥ 0.8) after carpal tunnel release in Korean patients with CTS, which is comparable to the other language versions of the DASH. Although it was less responsive than the CTQ, which is disease-specific, the region-specific K-DASH can be used as an effective outcome measurement tool for CTS, and especially for research that compares CTS with other upper limb conditions.