The Validity,Reliability,Responsiveness,and Bias of the Manchester-Modified Disability of the Arm,Shoulder,and Hand Score in Hand Injuries

Abstract

The Manchester-Modified Disability of Arm, Shoulder and Hand questionnaire (M² DASH) was developed by the authors as a modification to the original DASH questionnaire. In this study, we assessed the validity, reliability, responsiveness, and bias of the M² DASH questionnaire for hand injuries using completed M² DASH, Patient Evaluation Measure, and Michigan Hand Outcome questionnaires from 40 patients. The M² DASH scores showed significant positive correlations with the Patient Evaluation Measure and Michigan Hand Outcome scores suggesting validity. There was also no evidence of a statistical difference in the M² DASH scores when the condition had stabilized suggesting good test–retest reproducibility and reliability. The effect size and the standardized response mean for the M² DASH score were greater than those for the Patient Evaluation Measure and Michigan Hand Outcome scores establishing that the M² DASH is highly responsive. There was no gender, hand dominance, or dominant side injured bias for the M² DASH score. There was, however, a relatively weak association between age and the M² DASH score at presentation. We conclude that the M² DASH questionnaire is a robust region-specific outcome measure. It is a valid and responsive questionnaire with test–retest reliability proven for hand injuries in this study. Gender, handedness, and side injured did not cause bias in the responses.