Impact of radiologic variables on item responses of ODI, SRS22 and SF-36. in adult spinal deformity patients: differential item functioning (DIF) analysis results from a multi-center database

Kieser D., YÜKSEL S., Boissiere L., Yilgor C., Cawley D., Hayashi K., ...More

European Spine Journal, 2022 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1007/s00586-021-07088-5
  • Title of Journal : European Spine Journal
  • Keywords: Spine, Deformity, Surgery, Scoliosis, Cobb, PARAMETERS, SURGERY, REOPERATION, RATES, TILT


© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Purpose: To determine if responses given to each question of the Scoliosis Research Society-22 (SRS22), Oswestry disability index (ODI) and Short Form-36 (SF-36) questionnaires are influenced by the radiological parameters. Methods: Patients enrolled in a multi-centre prospectively collected adult spinal deformity database who had complete SRS22, ODI and SF-36 data at baseline and at one-year follow-up were analysed. The presence of a differential item function of each question within each score in relation to radiological parameters was analysed using a mixed Rasch model with the radiological threshold value(s) determined. Results: Of those patients analysed (n = 1745; 1406 female, average age 51.0 ± 19.8 years), 944 were surgically and 801 were non-surgically treated. For the SRS22, questions (Q) 3, 5 and 18 were sensitive to almost all radiological parameters and the overall score was found sensitive to the Cobb angle. For the ODI, Q3, 6, 9 and 10 were not sensitive to any radiologic parameters whereas Q4 and 5 were sensitive to most. In contrast, only 3 of the SF-36 items were sensitive to radiological parameters. Conclusions: 78% of the SRS-22, 60% of the ODI and 8% of the questions in the SF-36 are sensitive to radiological parameters. Sagittal imbalance is independently associated with a poor overall outcome, but affects mental status and function more than pain and self-image. The assembly of questions responsive to radiological parameters may be useful in establishing a connection between changes in radiologic parameters and HRQL.