Construct validity, reliability, response rate, and association with disease activity of the quick disabilities of the arm, shoulder and hand questionnaire in the assessment of rheumatoid arthritis

Objective. First objective is to validate the Disabilities of the Arm, Shoulder and Hand (DASH) and Quick DASH (QuickDASH) questionnaire in rheumatoid arthritis (RA) patients with functional upper extremity impairment. Next is to clarify which clinical factor is associating with QuickDASH using a large cohort of RA. Methods. The QuickDASH and DASH were applied to our 94 RA patients who underwent surgery for functional upper extremity impairment. Next, the QuickDASH was applied to our cohort of 5191 Japanese patients with RA. Results. In the first cohort of 94 RA patients, both QuickDASH and DASH displayed excellent reliability and validity. The response rate of patients < 65 and ³ 65 years of age showed significant difference in the DASH but not in the QuickDASH. In the second cohort with 5191 RA patients, QuickDASH showed a high response rate (93%) and good to moderate correlation with Japanese version of the Health Assessment Questionnaire (r = 0.88) and disease activity score of 28 (DAS28, r = 0.53). Change in QuickDASH score and DAS28-based European League Against Rheumatism response showed significant correlation. Conclusion. QuickDASH seems suitable for evaluating upper extremity impairment, disability index, and disease control in a large cohort of RA patients including elderly patients.