title: Spinal appearance questionnaire: factor analysis, scoring, reliability, and validity testing.
abstract: METHODS
  Cross sectional.
  
  
  OBJECTIVE
  This study presents the factor analysis of the Spinal Appearance Questionnaire (SAQ) and its psychometric properties.
  
  
  BACKGROUND
  Although the SAQ has been administered to a large sample of patients with adolescent idiopathic scoliosis (AIS) treated surgically, its psychometric properties have not been fully evaluated. This study presents the factor analysis and scoring of the SAQ and evaluates its psychometric properties.
  
  
  METHODS
  The SAQ and the Scoliosis Research Society-22 (SRS-22) were administered to AIS patients who were being observed, braced or scheduled for surgery. Standard demographic data and radiographic measures including Lenke type and curve magnitude were also collected.
  
  
  RESULTS
  Of the 1802 patients, 83% were female; with a mean age of 14.8 years and mean initial Cobb angle of 55.8° (range, 0°-123°). From the 32 items of the SAQ, 15 loaded on two factors with consistent and significant correlations across all Lenke types. There is an Appearance (items 1-10) and an Expectations factor (items 12-15). Responses are summed giving a range of 5 to 50 for the Appearance domain and 5 to 20 for the Expectations domain. The Cronbach's α was 0.88 for both domains and Total score with a test-retest reliability of 0.81 for Appearance and 0.91 for Expectations. Correlations with major curve magnitude were higher for the SAQ Appearance and SAQ Total scores compared to correlations between the SRS Appearance and SRS Total scores. The SAQ and SRS-22 Scores were statistically significantly different in patients who were scheduled for surgery compared to those who were observed or braced.
  
  
  CONCLUSIONS
  The SAQ is a valid measure of self-image in patients with AIS with greater correlation to curve magnitude than SRS Appearance and Total score. It also discriminates between patients who require surgery from those who do not.
authors.affiliation: Norton Leatherman Spine Center, Louisville, KY, USA. leah.carreon@nortonhealthcare.org
authors.forename: Leah Y
authors.initials: LY
authors.lastname: Carreon
authors.forename: James O
authors.initials: JO
authors.lastname: Sanders
authors.forename: David W
authors.initials: DW
authors.lastname: Polly
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sucato
authors.forename: Stefan
authors.initials: S
authors.lastname: Parent
authors.forename: Marjolaine
authors.initials: M
authors.lastname: Roy-Beaudry
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Hopkins
authors.forename: Anna
authors.initials: A
authors.lastname: McClung
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Bratcher
authors.forename: Beverly E
authors.initials: BE
authors.lastname: Diamond
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D011300:Preoperative Care / Q000523:psychology; D057234:Preoperative Period; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology; D015203:Reproducibility of Results; D012600:Scoliosis / Q000523:psychology* / Q000601:surgery; D012649:Self Concept; D013131:Spine / Q000473:pathology* / Q000601:surgery; D011795:Surveys and Questionnaires / Q000592:standards*