Psychometric Properties of the Scoliosis Research Society Questionnaire (Version 22r) Domains Among Adults With Spinal Deformity : A Rasch Measurement Theory Analysis

Objective: Adults with degenerative spinal deformity (ASD) have lower health-related quality of life (HRQL) compared to the general population. Applying Rasch Measurement Theory (RMT), this study tested the revised Scoliosis Research Society-22 (SRS-22r) HRQL instrument among symptomatic adult patients with degenerative spinal disorders and varying degrees of ASD. Methods: SRS-22r data from 637 outpatient spine clinic patients with degenerative spine conditions were investigated for unidimensionality, item/scale fit, differential item functioning (DIF), scale coverage/targeting, and person separation index (PSI) using RMT. Results: Unidimensionality of the SRS-22r was not supported for eith…