title: Discriminative Properties of the Spinal Appearance Questionnaire Compared With the Scoliosis Research Society-22 Revised.
abstract: METHODS
  Longitudinal cohort.
  
  
  OBJECTIVE
  To determine the responsiveness of the Spinal Appearance Questionnaire (SAQ) in patients with adolescent idiopathic scoliosis (AIS) undergoing surgical correction of the deformity.
  
  
  BACKGROUND
  The SAQ has been found to be a valid and reliable measure in patients with AIS. A recently published factor analysis and scoring system has been shown to be applicable to all Lenke types and had greater correlation to the curve magnitude than the Scoliosis Research Society (SRS) Appearance and Total score.
  
  
  METHODS
  From a prospective multicenter database, 126 AIS patients who underwent correction of the spinal deformity with complete SAQ and SRS-22 Revised data at baseline and 2-year follow-up were identified. Discriminative properties of the SAQ domains (Expectations, Appearance, and Total) and SRS domains (Appearance, Activity, Pain, Mental, Satisfaction, and Total) were compared by computing the effect size (ES) and the standardized response mean (SRM).
  
  
  RESULTS
  The SAQ Total had the largest ES (1.8) and SRM (1.5). This was followed by the SAQ Appearance, with an ES of 1.7 and SRM of 1.4; and the SAQ Expectations, with an ES of 1.5 and SRM of 1.2. Among the different SRS domains, only the Appearance (ES = 1.2, SRM = 1.1), Satisfaction (ES = 0.8, SRM = 0.6), and Total scores (ES = 0.8, SRM = 0.9) had effect sizes that were considered large. The SRS Mental domain had a moderate effect size (ES = 0.3, SRM = 0.3), whereas the Activity (ES = 0.0, SRM = 0.0) and Pain (ES = 0.2, SRM = 0.2) domains had small effect sizes.
  
  
  CONCLUSIONS
  The SAQ is sensitive and responsive to change, as evidenced by the large effect size for both domain and the Total score. The effect sizes are larger than those for any of the SRS domains, including Appearance and Total scores.
authors.affiliation: Norton Leatherman Spine Center, 210 East Gray Street, Suite 900, Louisville, KY 40202, USA. Electronic address: leah.carreon@nortonhealthcare.org.
authors.forename: Leah Y
authors.initials: LY
authors.lastname: Carreon
authors.affiliation: Department of Orthopaedics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, USA.
authors.forename: James O
authors.initials: JO
authors.lastname: Sanders
authors.affiliation: Department of Orthopaedic Surgery, University of California San Francisco, 400 Parnassus Avenue, San Francisco, CA 94143, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Diab
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, 2450 Riverside Avenue South, Suite R200, Minneapolis, MN 55454, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Polly
authors.affiliation: PhDx Systems, 1001 University Boulevard SE, Suite 103, Albuquerque, NM 87106, USA.
authors.forename: Beverly E
authors.initials: BE
authors.lastname: Diamond
authors.affiliation: Department of Pediatric Orthopedic Surgery, Texas Scottish Rite Hospital for Children, 2222 Welborn Street, Dallas, TX 75219, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sucato
keywords: Adolescent idiopathic scoliosis; Discriminative properties; Psychometrics; Responsiveness to change; Spinal Appearance Questionnaire