High correlation but limited agreement: reassessing the stand-alone use of the Single Assessment Numeric Evaluation score compared to American Shoulder and Elbow Surgeons score after rotator cuff repair

Although American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores will demonstrate consistently strong correlation across all timepoints, they will show poor agreement during the preoperative and early postoperative phases. This divergence will indicate that the 2 instruments are not clinically interchangeable, particularly when assessing early recovery. We retrospectively analyzed 302 patients who underwent rotator cuff repair between 2019 and 2022 within a standardized clinical care pathway. Spearman correlation and Bland-Altman agreement analyses were performed between ASES and SANE scores at preoperative, 3-, 6-, and 12-month follow-up. Subgroup analyses were conducted by sex and limb dominance. Correlation between ASES and SANE scores increased over time, from moderate preoperatively (r = 0.41) to very high at 12 months (r = 0.91). However, Bland-Altman analysis revealed wide limits of agreement (LoA) at all time points, particularly preoperatively (mean difference = -7.5; LoA: -48.6 to 33.6), indicating clinically relevant discrepancies. At 12 months, agreement improved (mean difference = -1.5; LoA: -15.7 to 12.7), but remained outside commonly accepted Minimal Clinically Important Difference thresholds. Correlation patterns were consistent across sex and dominance subgroups. Although ASES and SANE scores are highly correlated at 1 year, they are not clinically interchangeable-particularly during early recovery. While SANE may be acceptable as a stand-alone measure in select settings, our findings suggest it should be used to complement-rather than replace-multidimensional tools like ASES when nuanced functional assessment is required.