A novel methodology for establishing minimum clinically important difference and substantial clinical benefit thresholds for patient-reported outcome measures following reverse total shoulder arthroplasty

Abstract

Background

Increasing reliance on patient-reported outcome measures (PROMs) following reverse total shoulder arthroplasty (rTSA) has resulted in variability in the thresholds for minimum clinically important difference (MCID) and substantial clinical benefit (SCB) reported in the literature. In this study, we aimed to identify the best threshold values for MCID and SCB for common rTSA PROMs.

Methods

The PubMed, Embase, MEDLINE, Cochrane Library, and Google Scholar databases were queried for studies published from January 1, 2000 to March 1, 2024 that identified clinically significant thresholds for PROMs following rTSA. The threshold calculation method, anchor questions/response options, follow-up duration, and confidence intervals were extracted. A novel hierarchical methodology evaluated various threshold calculation characteristics to identify the best MCID and SCB values following rTSA.

Results

We included 37 studies for analysis comprising 11,960 patients. Using our methodology, the MCID values from the literature we recommend for American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test (SST), Constant-Murley Shoulder Outcome Score (Constant), University of California at Los Angeles Shoulder Score (UCLA), Shoulder Pain and Disability Index (SPADI) score, and Visual Analog Scale (VAS) following rTSA are 8.9, 3.7, 9.3, 2.9, 20, and 1.4, respectively. The recommended MCID threshold values for ASES and SST were from Werner and McLaughlin, respectively. The recommended thresholds for Constant and UCLA were from Zhou, while the thresholds for SPADI and VAS were from Simovitch. Using our methodology, the SCB threshold values from the literature we recommend for ASES following rTSA are 28.3 for glenohumeral osteoarthritis and 23.1 for rotator cuff arthropathy from Puzzitiello. For SST, Constant, UCLA, SPADI, and VAS, the SCB values we recommend are 3.2, 13.6, 10.4, 42.7, and 2.6, respectively. The recommended SCB thresholds for SST, Constant, UCLA, SPADI, and VAS were all from Simovitch.

Conclusion

We present recommended MCID and SCB values identified through our comprehensive methodology and recommend how these thresholds should be calculated for common rTSA PROMs moving forward. With increasing use and dependence on MCID and SCB values for PROMs, these recommended threshold values for MCID and SCB will help standardize assessment of clinically significant improvement for patients undergoing rTSA.