title: Are the El Escorial and Revised El Escorial criteria for ALS reproducible? A study of inter-observer agreement.
abstract: BACKGROUND
  For accurate diagnosis, inter-observer agreement of criteria is important.
  
  
  METHODS
  Using case records, the reproducibility of the original and revised El Escorial diagnostic criteria for amyotrophic lateral sclerosis were tested in a consecutive series of people referred to the Scottish Motor Neuron Disease Register.
  
  
  RESULTS
  Agreement between independent observers was similar (weighted kappa: 0.783, 95% CI 0.656 to 0.911 (original criteria), 0.681, 95% CI 0.485 to 0.878 (revised)).
  
  
  CONCLUSIONS
  Serious errors are unlikely, but the revised criteria may be less reproducible as they include more diagnostic categories. Revisions of diagnostic criteria should be tested for reproducibility and validity prior to widespread adoption.
authors.affiliation: The Scottish Motor Neuron Disease Register, Ninewells Hospital and Medical School, Dundee, UK. Raeburnforbes@aol.com
authors.forename: R B
authors.initials: RB
authors.lastname: Forbes
authors.forename: S
authors.initials: S
authors.lastname: Colville
authors.forename: R J
authors.initials: RJ
authors.lastname: Swingler
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D016001:Confidence Intervals; D006801:Humans; D009460:Neurologic Examination / Q000706:statistics & numerical data; D015588:Observer Variation; D012042:Registries / Q000706:statistics & numerical data*