Minimal important change and other measurement properties of the Oxford Elbow Score and the Quick Disabilities of the Arm, Shoulder, and Hand in patients with a simple elbow dislocation; validation study alongside the multicenter FuncSiE trial

Study design: Validation study using data from a multicenter, randomized, clinical trial (RCT). Objectives: To evaluate the reliability, validity, responsiveness, and minimal important change (MIC) of the Dutch version of the Oxford Elbow Score (OES) and the Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) in patients with a simple elbow dislocation. Background: Patient-reported outcome measures are increasingly important for assessing outcome following elbow injuries, both in daily practice and in clinical research. However measurement properties of the OES and Quick-DASH in these patients are not fully known. Methods: OES and Quick-DASH were completed four times until one year after trauma. Mayo Elbow Performance Index, pain (VAS), Short Form-36, and EuroQol-5D were completed for comparison. Data of a multicenter RCT (n = 100) were used. Internal consistency was determined using Cronbach’s alpha. Construct and longitudinal validity were assessed by determining hypothesized strength of correlation between scores or changes in scores, respectively, of (sub)scales. Finally, floor and ceiling effects, MIC, and smallest detectable change (SDC) were determined. Results: OES and Quick-DASH demonstrated adequate internal consistency (Cronbach α, 0.882 and 0.886, respectively). Construct validity and longitudinal validity of both scales were supported by >75% correctly hypothesized correlations. MIC and SDC were 8.2 and 12.0 point for OES, respectively. For Quick-DASH, these values were 11.7 and 25.0, respectively. Conclusions: OES and Quick-DASH are reliable, valid, and responsive instruments for evaluating elbow-related quality of life. The anchor-based MIC was 8.2 points for OES and 11.7 for Quick-DASH.