Exploratory anchor-derived six-month improvement thresholds for sleep quality and pain after reverse total shoulder arthroplasty.

Background: Sleep disturbance is a common patient-reported problem in patients undergoing reverse total shoulder arthroplasty (rTSA). However, clinically interpretable improvement thresholds for sleep quality after rTSA remain unclear. This study aimed to derive exploratory anchor-based 6-month improvement thresholds for sleep quality, assessed using the Pittsburgh Sleep Quality Index (PSQI), and pain, assessed using the visual analog scale (VAS), after rTSA. Methods: Sixty-one patients undergoing primary rTSA with complete pre-operative and 6-month post-operative PSQI, VAS, and global rating of change (GRC) data were retrospectively analyzed. Exploratory receiver-operating characteristic (ROC) curve analyses were performed using the GRC anchor, and Youden-derived thresholds were calculated. Anchor validity was assessed using Spearman correlation analysis between ordinal GRC responses and changes in PSQI and VAS. Results: rTSA was associated with significant 6-month improvements in both PSQI and VAS scores (both Conclusion: rTSA was associated with substantial 6-month improvements in sleep quality and pain. In this small retrospective cohort, exploratory anchor-based ROC analyses generated preliminary improvement thresholds of approximately 7 points for PSQI and 4 points for VAS pain. However, the weak PSQI anchor correlation, severe imbalance in anchor-defined groups, and modest ROC discrimination indicate that these estimates should be considered hypothesis-generating rather than definitive Minimal Clinically Important Difference values.