title: Spinal instability neoplastic score: an analysis of reliability and validity from the spine oncology study group.
abstract: OBJECTIVE
  Standardized indications for treatment of tumor-related spinal instability are hampered by the lack of a valid and reliable classification system. The objective of this study was to determine the interobserver reliability, intraobserver reliability, and predictive validity of the Spinal Instability Neoplastic Score (SINS).
  
  
  METHODS
  Clinical and radiographic data from 30 patients with spinal tumors were classified as stable, potentially unstable, and unstable by members of the Spine Oncology Study Group. The median category for each patient case (consensus opinion) was used as the gold standard for predictive validity testing. On two occasions at least 6 weeks apart, each rater also scored each patient using SINS. Each total score was converted into a three-category data field, with 0 to 6 as stable, 7 to 12 as potentially unstable, and 13 to 18 as unstable.
  
  
  RESULTS
  The κ statistics for interobserver reliability were 0.790, 0.841, 0.244, 0.456, 0.462, and 0.492 for the fields of location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement, respectively. The κ statistics for intraobserver reliability were 0.806, 0.859, 0.528, 0.614, 0.590, and 0.662 for the same respective fields. Intraclass correlation coefficients for inter- and intraobserver reliability of total SINS score were 0.846 (95% CI, 0.773 to 0.911) and 0.886 (95% CI, 0.868 to 0.902), respectively. The κ statistic for predictive validity was 0.712 (95% CI, 0.676 to 0.766).
  
  
  CONCLUSIONS
  SINS demonstrated near-perfect inter- and intraobserver reliability in determining three clinically relevant categories of stability. The sensitivity and specificity of SINS for potentially unstable or unstable lesions were 95.7% and 79.5%, respectively.
authors.affiliation: University of Saskatchewan, Royal University Hospital, 103 Hospital Dr, Saskatoon, Saskatchewan, Canada. daryl.fourney@usask.ca
authors.forename: Daryl R
authors.initials: DR
authors.lastname: Fourney
authors.forename: Evan M
authors.initials: EM
authors.lastname: Frangou
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Ryken
authors.forename: Christian P
authors.initials: CP
authors.lastname: Dipaola
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Shaffrey
authors.forename: Sigurd H
authors.initials: SH
authors.lastname: Berven
authors.forename: Mark H
authors.initials: MH
authors.lastname: Bilsky
authors.forename: James S
authors.initials: JS
authors.lastname: Harrop
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fehlings
authors.forename: Stefano
authors.initials: S
authors.lastname: Boriani
authors.forename: Dean
authors.initials: D
authors.lastname: Chou
authors.forename: Meic H
authors.initials: MH
authors.lastname: Schmidt
authors.forename: David W
authors.initials: DW
authors.lastname: Polly
authors.forename: Roberto
authors.initials: R
authors.lastname: Biagini
authors.forename: Shane
authors.initials: S
authors.lastname: Burch
authors.forename: Mark B
authors.initials: MB
authors.lastname: Dekutoski
authors.forename: Aruna
authors.initials: A
authors.lastname: Ganju
authors.forename: Peter C
authors.initials: PC
authors.lastname: Gerszten
authors.forename: Ziya L
authors.initials: ZL
authors.lastname: Gokaslan
authors.forename: Michael W
authors.initials: MW
authors.lastname: Groff
authors.forename: Norbert J
authors.initials: NJ
authors.lastname: Liebsch
authors.forename: Ehud
authors.initials: E
authors.lastname: Mendel
authors.forename: Scott H
authors.initials: SH
authors.lastname: Okuno
authors.forename: Shreyaskumar
authors.initials: S
authors.lastname: Patel
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Rhines
authors.forename: Peter S
authors.initials: PS
authors.lastname: Rose
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sciubba
authors.forename: Narayan
authors.initials: N
authors.lastname: Sundaresan
authors.forename: Katsuro
authors.initials: K
authors.lastname: Tomita
authors.forename: Peter P
authors.initials: PP
authors.lastname: Varga
authors.forename: Luiz R
authors.initials: LR
authors.lastname: Vialle
authors.forename: Frank D
authors.initials: FD
authors.lastname: Vrionis
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Charles G
authors.initials: CG
authors.lastname: Fisher
mesh_terms: D002574:Cervical Vertebrae / Q000503:physiopathology; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000503:physiopathology; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013125:Spinal Neoplasms / Q000503:physiopathology*; D013131:Spine / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000503:physiopathology