title: Interobserver agreement for the spine instability neoplastic score varies according to the experience of the evaluator.
abstract: OBJECTIVE
  To evaluate the interobserver agreement for the Neoplastic Spine Instability Score (SINS) among spine surgeons with or without experience in vertebral metastasis treatment and physicians in other specialties.
  
  
  METHODS
  Case descriptions were produced based on the medical records of 40 patients with vertebral metastases. The descriptions were then published online. Physicians were invited to evaluate the descriptions by answering questions according to the Neoplastic Spine Instability Score (SINS). The agreement among physicians was calculated using the kappa coefficient.
  
  
  RESULTS
  Seventeen physicians agreed to participate: three highly experienced spine surgeons, seven less-experienced spine surgeons, three surgeons of other specialties, and four general practitioners (n = 17). The agreement for the final SINS score among all participants was fair, and it varied according to the SINS component. The agreement was substantial for the spine location only. The agreement was higher among experienced surgeons. The agreement was nearly perfect for spinal location among the spine surgeons who were highly experienced in vertebral metastases.
  
  
  CONCLUSIONS
  This study demonstrates that the experience of the evaluator has an impact on SINS scale classification. The interobserver agreement was only fair among physicians who were not spine surgeons and among spine surgeons who were not experienced in the treatment of vertebral metastases, which may limit the use of the SINS scale for the screening of unstable lesions by less-experienced evaluators.
authors.affiliation: Spine Surgery Division, Instituto do Câncer do Estado de São Paulo, São Paulo, SP, Brazil. williamgjteixeira@gmail.com
authors.forename: William Gemio Jacobsen
authors.initials: WG
authors.lastname: Teixeira
authors.forename: Pedro Ricardo de Mesquita
authors.initials: PR
authors.lastname: Coutinho
authors.forename: Luiz Delboni
authors.initials: LD
authors.lastname: Marchese
authors.forename: Douglas Kenji
authors.initials: DK
authors.lastname: Narazaki
authors.forename: Alexandre Fogaça
authors.initials: AF
authors.lastname: Cristante
authors.forename: Manoel Jacobsen
authors.initials: MJ
authors.lastname: Teixeira
authors.forename: Tarcísio Eloy Pessoa de
authors.initials: TE
authors.lastname: Barros Filho
authors.forename: Olavo Pires de
authors.initials: OP
authors.lastname: Camargo
mesh_terms: D001938:Brazil; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000503:physiopathology; D015588:Observer Variation; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013125:Spinal Neoplasms / Q000503:physiopathology* / Q000556:secondary; D013131:Spine / Q000503:physiopathology*