Reliability, Validity, and Responsiveness of the QuickDASH in Patients With Upper Limb Amputation.

Abstract

To examine the internal consistency, test-retest reliability, validity, and responsiveness of the shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire in persons with upper limb amputation. Cross-sectional and longitudinal. Three sites participating in the U.S. Department of Veterans Affairs Home Study of the DEKA Arm. A convenience sample of upper limb amputees (N=44). Training with a multifunction upper limb prosthesis. Multiple outcome measures including the QuickDASH were administered twice within 1 week, and for a subset of 20 persons, after completion of in-laboratory training with the DEKA Arm. Scale alphas and intraclass correlation coefficient type 3,1 (ICC3,1) were used to examine reliability. Minimum detectable change (MDC) scores were calculated. Analyses of variance, comparing QuickDASH scores by the amount of prosthetic use and amputation level, were used for known-group validity analyses with alpha set at .05. Pairwise correlations between QuickDASH and other measures were used to examine concurrent validity. Responsiveness was measured by effect size (ES) and standardized response mean (SRM). QuickDASH alpha was .83, and ICC was .87 (95% confidence interval, .77-.93). MDC at the 95% confidence level (MDC95%) was 17.4. Full- or part-time prosthesis users had better QuickDASH scores compared with nonprosthesis users (P=.021), as did those with more distal amputations at both baseline (P=.042) and with the DEKA Arm (P=.024). The QuickDASH was correlated with concurrent measures of activity limitation as expected. The ES and SRM after training with the DEKA Arm were 0.6. This study provides evidence of reliability and validity of the QuickDASH in persons with upper limb amputation. Results provide preliminary evidence of responsiveness to prosthetic device type/training. Further research with a larger sample is needed to confirm results.