The purpose of this study was to compare the correlation, responsiveness, and responder and administrator burden of the American Shoulder and Elbow Surgeons (ASES) score with the Western Ontario Osteoarthritis of the Shoulder (WOOS) score for patients undergoing total shoulder arthroplasty. The goal was to determine whether one score was superior to the other to limit the use of multiple scoring measures when tracking patient outcomes. The hypothesis of this study was that for patients undergoing total shoulder arthroplasty, the WOOS score would have (1) a high level of correlation with the ASES score, (2) comparable responsiveness to the ASES score, and (3) a higher responder and administrator burden than the ASES score.
We performed a retrospective review of a database of patients undergoing total shoulder arthroplasty in which the ASES score was recorded with the WOOS score. Correlations were determined using the Pearson coefficient. Subgroup analysis was performed to determine whether correlations differed in (1) preoperative outcome and (2) postoperative outcome determinations and by type of arthroplasty (anatomic vs. reverse). Responsiveness was determined by calculating the standardized response mean and the effect size of both scores. Responder and administrator burden was examined using 50 consecutive preoperative patients to determine the number of incorrectly completed WOOS and ASES scores.
The correlation of the ASES and WOOS scores for all patients was excellent (n = 1218, r = 0.88, P < .0001). The correlation of the ASES and WOOS scores was excellent for patients undergoing anatomic total shoulder arthroplasty (n = 695, r = 0.71, P < .0001) and reverse total shoulder arthroplasty (n = 523, r = 0.88, P < .0001). The correlation of preoperative scores was strong-moderate (n = 606, r = 0.62, P < .0001), and that of postoperative scores was strong-moderate (n = 612, r = 0.69, P < .0001). The standardized response mean (WOOS score, 2.1; ASES score, 2.1) and the effect size (WOOS score, 3.0; ASES score, 3.0) demonstrated comparable responsiveness. Twenty-six percent of the WOOS scores were completed incorrectly and were invalid compared with 0% of the ASES scores (P < .0001).
There is excellent correlation and comparable responsiveness between the ASES score and WOOS score. Including these scores simultaneously when tracking patient-determined outcomes appears to be redundant and therefore unnecessary. Because there is higher responder and administrative burden for the WOOS score, we recommend use of the ASES score over the WOOS score in patients undergoing total shoulder arthroplasty.