Outcomes Discriminative Properties of the Spinal Appearance Questionnaire Compared With the Scoliosis Research Societye22 Revised Leah Y. Carreon, MD, MSc a, * , James O. Sanders, MD b , Mohammad Diab, MD c , David W. Polly, MD d , Beverly E. Diamond, PhD e , Daniel J. Sucato, MD, MS f a Norton Leatherman Spine Center, 210 East Gray Street, Suite 900, Louisville, KY 40202, USA b Department of Orthopaedics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, USA c Department of Orthopaedic Surgery, University of California San Francisco, 400 Parnassus Avenue, San Francisco, CA 94143, USA d Department of Orthopaedic Surgery, University of Minnesota, 2450 Riverside Avenue South, Suite R200, Minneapolis, MN 55454, USA e PhDx Systems, 1001 University Boulevard SE, Suite 103, Albuquerque, NM 87106, USA f Department of Pediatric Orthopedic Surgery, Texas Scottish Rite Hospital for Children, 2222 Welborn Street, Dallas, TX 75219, USA Received 25 February 2013; revised 17 April 2013; accepted 7 June 2013 Abstract Study Design: Longitudinal cohort. Objectives: To determine the responsiveness of the Spinal Appearance Questionnaire (SAQ) in patients with adolescent idiopathic scoliosis (AIS) undergoing surgical correction of the deformity. Summary of Background Data: 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 (Expec- tations, 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 5 1.2, SRM 5 1.1), Satisfaction (ES 5 0.8, SRM 5 0.6), and Total scores (ES 5 0.8, SRM 5 0.9) had effect sizes that were considered large. The SRS Mental domain had a moderate effect size (ES 5 0.3, SRM 5 0.3), whereas the Activity (ES 5 0.0, SRM 5 0.0) and Pain (ES 5 0.2, SRM 5 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. Ó 2013 Scoliosis Research Society. Keywords: Adolescent idiopathic scoliosis; Spinal Appearance Questionnaire; Psychometrics; Responsiveness to change; Discriminative properties Author disclosures: LYC (funds provided to database company by Medtronic and Nuvasive; board membership with Spine, The Spine Journal, University of Louisville IRB, Medtronic; employment with Norton Healthcare; grants from Norton Healthcare, Orthopedic Educa- tional and Research Fund; travel/accommodations/meeting expenses from Orthopedic Educational and Research Fund, National Institutes of Health, University of Louisville IRB, Department of Defense, Asso- ciation for Collaborative Spine Research; honoraria from Medtronic and National Institutes of Health); JOS (grants from POSNA, CWSDSG; payment for development of educational presentations from DePuy; stock/stock options from Abbot Labs, Hospira, Abbvie, GE, Biomedical Enterprises; travel/accommodations/meeting expenses from DePuy); MD (funds provided to database company by Medtronic and Nuvasive; consultancy for Fixes 4 Kids; grants from OREF; stock/stock options from Fixes for Kids); DWP (consultancy for Medtronic; funds provided to database company by Medtronic and Nuvasive; grants from Depart- ment of Defense, Orthopedic Research and Education Fund, Chest Wall and Spine Deformity Foundation, Minnesota Medical Foundation); BED (funds provided to database company by Medtronic and Nuvasive); DJS (funds provided to database company by Medtronic and Nuvasive; board membership with Scoliosis Research Society). *Corresponding author. Norton Leatherman Spine Center, 210 East Gray Street, Suite 900, Louisville, KY 40202, USA. Tel.: (502) 584- 7525; fax: (502) 584-6851. E-mail address: leah.carreon@nortonhealthcare.org (L.Y. Carreon). 2212-134X/$ - see front matter Ó 2013 Scoliosis Research Society. http://dx.doi.org/10.1016/j.jspd.2013.06.001 Spine Deformity 1 (2013) 328e338 www.spine-deformity.org