title: Determining the minimal clinically important difference for the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and visual analog scale (VAS) measuring pain after shoulder arthroplasty.
abstract: BACKGROUND
  Minimal clinically important differences (MCIDs) for the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), and a visual analog scale (VAS) measuring pain have not been previously described using an anchor-based method after shoulder arthroplasty. The purpose of this study was to determine the MCIDs for these measures after shoulder arthroplasty for glenohumeral arthritis or advanced rotator cuff disease.
  
  
  METHODS
  Primary anatomic total shoulder arthroplasty (TSA), primary reverse TSA, or hemiarthroplasty was performed in 326 patients by 1 of 5 shoulder and elbow surgeons. The SST score, ASES score, and VAS pain score were collected preoperatively and at a minimum of 2 years postoperatively (mean, 3.5 years). The MCIDs were calculated for the ASES score, SST score, and VAS pain score using an anchor-based method.
  
  
  RESULTS
  The MCIDs for the ASES score, SST score, and VAS pain score were 20.9 (P < .001), 2.4 (P < .0001), and 1.4 (P = .0158), respectively. Duration of follow-up and type of arthroplasty (anatomic TSA vs reverse TSA) did not have a significant effect on the MCIDs (P > .1) except shorter follow-up correlated with a larger MCID for the ASES score (P = .0081). Younger age correlated with larger MCIDs for all scores (P < .024). Female sex correlated with larger MCIDs for the VAS pain score (P = .123) and ASES score (P = .05).
  
  
  CONCLUSIONS
  Patients treated with a shoulder arthroplasty require a 1.4-point improvement in the VAS pain score, a 2.4-point improvement in the SST score, and a 21-point improvement in the ASES score to achieve a minimal clinical importance difference from the procedure.
authors.affiliation: Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT, USA. Electronic address: Robert.Tashjian@hsc.utah.edu.
authors.forename: Robert Z
authors.initials: RZ
authors.lastname: Tashjian
authors.affiliation: Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT, USA; Division of Epidemiology, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: Man
authors.initials: M
authors.lastname: Hung
authors.affiliation: Department of Orthopaedics, Washington University, St. Louis, MO, USA.
authors.forename: Jay D
authors.initials: JD
authors.lastname: Keener
authors.affiliation: Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: Randy Christopher
authors.initials: RC
authors.lastname: Bowen
authors.affiliation: Department of Orthopaedics, Washington University, St. Louis, MO, USA.
authors.forename: Jared
authors.initials: J
authors.lastname: McAllister
authors.affiliation: Division of Epidemiology, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, Washington University, St. Louis, MO, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Ebersole
authors.affiliation: Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT, USA.
authors.forename: Erin K
authors.initials: EK
authors.lastname: Granger
authors.affiliation: Department of Orthopaedics, Washington University, St. Louis, MO, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Chamberlain
mesh_terms: D000328:Adult; D000368:Aged; D000072228:Arthroplasty, Replacement, Shoulder; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D000071081:Minimal Clinically Important Difference; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012189:Retrospective Studies; D012785:Shoulder Joint; D016896:Treatment Outcome; D064232:Visual Analog Scale
keywords: ASES score; Shoulder arthroplasty; Simple Shoulder Test; function; minimal clinically important difference; outcome scores; pain