Validation of DASH and QuickDASH for Outcome Assessment of Anatomic Total Shoulder Arthroplasty for Treatment of Advanced Glenohumeral Osteoarthritis.

Background: The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and its abbreviated version, QuickDASH, are commonly used patient-reported outcome measures (PROMs) for the assessment of an upper-extremity disability. Theoretically, they can be used to compare the treatment outcomes of different upper-extremity conditions. Despite increasingly widespread use for some shoulder conditions, these questionnaires have not been rigorously validated for use to assess the outcomes of patients undergoing anatomic total shoulder arthroplasty (aTSA). The objective of this study was to validate the DASH and QuickDASH scores for a longitudinal outcome assessment of patients undergoing aTSA to treat advanced glenohumeral osteoarthritis (GHOA).

Methods: In this study, 450 patients with a median age of 70.3 years (interquartile range [IQR] width, 11.7 years) were included; 52.4% of the patients were female. The DASH and QuickDASH questionnaires, the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), and the EuroQol-5 Dimensions (EQ-5D) questionnaire were completed preoperatively and at follow-ups of 3 months, 6 to 12 months, and a minimum of 2 years by patients undergoing aTSA. The criterion validity, construct validity, reliability, and responsiveness of the DASH and QuickDASH were assessed.

Results: The DASH and QuickDASH scores demonstrated moderate to very strong correlations with the ASES scores (ρ = -0.83 to -0.62), SST scores (ρ = -0.73 to -0.55), and EQ-5D scores (ρ = -0.72 to -0.57); minimal floor or ceiling effects; internal consistency (Cronbach alpha > 0.80); and large Cohen d and standardized response means (<1.6) at all time points. Very strong positive correlations were observed between the DASH and QuickDASH scores at all time points (ρ = 0.96 to 0.97).

Conclusions: The DASH and QuickDASH scores, which are region-specific rather than shoulder-specific, are valid, reliable, and responsive PROMs for the evaluation of patients with advanced GHOA treated with aTSA. Therefore, the DASH and QuickDASH scores can be used to compare the outcomes of aTSA for the treatment of advanced GHOA with the outcomes of treatment of other upper-extremity disorders, potentially facilitating comparative cost-effectiveness and value analysis studies.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.