title: Factors affecting the outcome in appearance of AIS surgery in terms of the minimal clinically important difference.
abstract: The minimal clinically important difference (MCID) of the Appearance domain of the SRS-22 questionnaire is an increase ≥1.0 in surgically treated patients with adolescent idiopathic scoliosis (AIS). However, no study has sought to identify the factors associated with an SRS-22 Appearance score increase greater than the MCID at 2 years.
  
  
  
  A retrospective analysis was performed on a prospectively collected multicenter database of 1020 surgically treated AIS patients with a minimum 2-year follow-up. Patients were divided into two cohorts: "I" = Improved after surgery (Δ Appearance ≥1.0) and "NI" = Not improved after surgery (Δ Appearance <1.0). Univariate regression was used to find a significant difference between the cohorts for individual measures. Multivariate logistic regression was used to find continuous predictors.
  
  
  
  663 (65%) patients were improved greater than the MCID, and 357 were not improved (35%). The improved cohort trended toward a greater percentage of underweight patients (p = 0.074) with lower preoperative SRS Appearance scores (p < 0.001) and larger preoperative trunk shifts (p = 0.033). Postoperatively, those patients with greater percent correction of thoracic (p = 0.021) and lumbar (p = 0.003) Cobb angles, smaller apical lumbar translation (p = 0.006), and a greater correction in trunk shift (p = 0.003) were most likely to attain the MCID.
  
  
  
  Several factors influence which patients are most likely to attain the MCID following surgery for AIS. Factors such as preoperative appearance scores and body weight are patient specific; other factors such as percent correction of the thoracic and lumbar Cobb angles, trunk shift, and lumbar apical translation may be influenced by the surgeon.
  
  
  
  II.
authors.affiliation: Shriners Hospitals for Children, 3551 N Broad Street, Philadelphia, 19140, PA, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Bennett
authors.affiliation: Shriners Hospitals for Children, 3551 N Broad Street, Philadelphia, 19140, PA, USA. asamdani@shrinenet.org.
authors.forename: Amer F
authors.initials: AF
authors.lastname: Samdani
authors.affiliation: Rady Children's Hospital, San Diego, CA, USA.
authors.forename: Tracey P
authors.initials: TP
authors.lastname: Bastrom
authors.affiliation: Shriners Hospitals for Children, 3551 N Broad Street, Philadelphia, 19140, PA, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ames
authors.affiliation: British Columbia Children's Hospital, Vancouver, BC, Canada.
authors.forename: Firoz
authors.initials: F
authors.lastname: Miyanji
authors.affiliation: Shriners Hospitals for Children, 3551 N Broad Street, Philadelphia, 19140, PA, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Pahys
authors.affiliation: Setting Scoliosis Straight Foundation, San Diego, CA, USA.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Marks
authors.affiliation: NYU Hospital for Joint Diseases, New York, NY, USA.
authors.forename: Baron S
authors.initials: BS
authors.lastname: Lonner
authors.affiliation: Rady Children's Hospital, San Diego, CA, USA.
authors.forename: Peter O
authors.initials: PO
authors.lastname: Newton
authors.affiliation: Nicklaus Children's Hospital, Miami, FL, USA.
authors.forename: Harry L
authors.initials: HL
authors.lastname: Shufflebarger
authors.affiliation: Rady Children's Hospital, San Diego, CA, USA.
authors.forename: Burt
authors.initials: B
authors.lastname: Yaszay
authors.affiliation: Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Flynn
authors.affiliation: Institute for Spine and Scoliosis, Lawrenceville, NJ, USA.
authors.forename: Randal R
authors.initials: RR
authors.lastname: Betz
authors.affiliation: Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Cahill
mesh_terms: D000293:Adolescent; D001835:Body Weight; D005260:Female; D006801:Humans; D008297:Male; D000071081:Minimal Clinically Important Difference; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012600:Scoliosis / Q000601:surgery*
keywords: MCID; Minimal clinically important difference; Outcome; SRS questionnaire; Scoliosis