The QuickDASH in the Assessment of Rheumatoid Arthritis Disease Activity

Abstract

Introduction: Rheumatoid Arthritis (RA) is a chronic inflammatory arthritis associated with substantial morbidity and mortality. Disease activity indices help guide therapy towards disease remission. This study studied whether the modified version of the Disabilities of Arm, Shoulder, and Hand (DASH), the QuickDASH, was valid in measuring RA disease activity. Methods: This prospective cohort study evaluated the performance of the QuickDASH in measuring RA disease activity as compared with the validated index, the Routine Assessment of Patient Index Data 3 (RAPID3). Both questionnaires were completed by subjects at each clinic visit. Primary endpoint was assessment of construct validity and reliability of the QuickDASH in the assessment of RA disease activity as compared to the RAPID3. Results: One-hundred and five patients enrolled in this study. There is a strong correlation between QuickDASH and RAPID3 (r=0.808, p<0.0001). The high reliability of the QuickDASH was indicated with an intraclass correlation coefficient (ICC) of 0.882 (95% CI: 0.864, 0.899) (p<0.0001). Internal consistency was strong (Cronbach alpha 0.894). Linear regression analysis yielded QuickDASH=3.595+(2.789*RAPID3). Reliability of the QuickDASH in capturing disease activity consistent with RAPID3 ranges was high with an ICC of 0.858 (95% CI 0.835, 0.877) (p<0.0001). Conclusion: This study demonstrated that the QuickDASH was very reliable and internally consistent in the measurement of RA disease activity. The QuickDASH correlates well with ranges of RA disease activity established by the RAPID3 and may be a surrogate for the RAPID3 in clinical practice.