title: Spine Instability Neoplastic Score: agreement across different medical and surgical specialties.
abstract: Spinal instability is an acknowledged complication of spinal metastases; in spite of recent suggested criteria, it is not clearly defined in the literature.
  
  
  
  This study aimed to assess intra and interobserver agreement when using the Spine Instability Neoplastic Score (SINS) by all physicians involved in its management.
  
  
  
  Independent multicenter reliability study for the recently created SINS, undertaken with a panel of medical oncologists, neurosurgeons, radiologists, orthopedic surgeons, and radiation oncologists, was carried out.
  
  
  
  Ninety patients with biopsy-proven spinal metastases and magnetic resonance imaging, reviewed at the multidisciplinary tumor board of our institution, were included.
  
  
  
  Intraclass correlation coefficient (ICC) was used for SINS score agreement. Fleiss kappa statistic was used to assess agreement on the location of the most affected vertebral level; agreement on the SINS category ("stable," "potentially stable," or "unstable"); and overall agreement with the classification established by tumor board.
  
  
  
  Clinical data and imaging were provided to 83 specialists in 44 hospitals across 14 Spanish regions. No assessment criteria were pre-established. Each clinician assessed the SINS score twice, with a minimum 6-week interval. Clinicians were blinded to assessments made by other specialists and to their own previous assessment. Subgroup analyses were performed by clinicians' specialty, experience (≤7, 8-13, ≥14 years), and hospital category (four levels according to size and complexity). This study was supported by Kovacs Foundation.
  
  
  
  Intra and interobserver agreement on the location of the most affected levels was "almost perfect" (κ>0.94). Intra-observer agreement on the SINS score was "excellent" (ICC=0.77), whereas interobserver agreement was "moderate" (ICC=0.55). Intra-observer agreement in SINS category was "substantial" (k=0.61), whereas interobserver agreement was "moderate" (k=0.42). Overall agreement with the tumor board classification was "substantial" (κ=0.61). Results were similar across specialties, years of experience, and hospital category.
  
  
  
  Agreement on the assessment of metastatic spine instability is moderate. The SINS can help improve communication among clinicians in oncology care.
authors.affiliation: Department of Radiology, Valencian Oncology Institute Foundation, C/ Beltrán Báguena, 19, 46009 Valencia, Spain; Research Institute in Health Services Foundation, C/ San Vicente,112, 3, 46007 Valencia, Spain; Spanish Back Pain Research Network, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain. Electronic address: aranae@uv.es.
authors.forename: Estanislao
authors.initials: E
authors.lastname: Arana
authors.affiliation: Spanish Back Pain Research Network, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain; Scientific Department, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Kovacs
authors.affiliation: Spanish Back Pain Research Network, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain; CIBER Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11. Planta 0, 28029 Madrid, Spain; Clinical Biostatistics Unit, Hospital Ramón y Cajal, IRYCIS. Ctra. Colmenar Km. 9.1, 28034 Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Royuela
authors.affiliation: Spanish Back Pain Research Network, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain; Department of Radiology, Hospital Regional Universitario Carlos Haya, Avda Carlos Haya s/n, 29010 Málaga, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Asenjo
authors.affiliation: Spanish Back Pain Research Network, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain; Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, CPI Building (8E), F access, 1st floor, Cami de Vera, s/n, 46022 Valencia, Spain.
authors.forename: Úrsula
authors.initials: Ú
authors.lastname: Pérez-Ramírez
authors.affiliation: Spanish Back Pain Research Network, Kovacs Foundation, Paseo de Mallorca 36, 07012 Palma de Mallorca, Spain; CIBER Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11. Planta 0, 28029 Madrid, Spain; Clinical Biostatistics Unit, Hospital Ramón y Cajal, IRYCIS. Ctra. Colmenar Km. 9.1, 28034 Madrid, Spain; Barts and the London School of Medicine & Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
authors.forename: Javier
authors.initials: J
authors.lastname: Zamora
mesh_terms: D001706:Biopsy; D032921:Consensus; D006801:Humans; D033183:Interdisciplinary Communication; D007593:Joint Instability / Q000145:classification* / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D008279:Magnetic Resonance Imaging; D000069471:Neurosurgeons; D015588:Observer Variation; D000072103:Oncologists; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013125:Spinal Neoplasms / Q000145:classification* / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology; D009626:Terminology as Topic
keywords: Medical specialty; Observer agreement; Reliability analysis; Spinal instability; Spinal metastases; Spine Instability Neoplastic Score