title: Survival analytical techniques were used to assess agreement of a quantitative variable.
abstract: OBJECTIVE
  Survival-agreement plots have been suggested as a new graphical approach to assess agreement in quantitative variables. We propose that survival analytical techniques can complement this method, providing a new analytical insight for agreement.
  
  
  METHODS
  Two survival-agreement plots are used to detect the bias between to measurements of the same variable. The presence of bias is tested with log-rank test, and its magnitude with Cox regression.
  
  
  RESULTS
  An example on C-reactive protein determinations shows how survival analytical methods would be interpreted in the context of assessing agreement.
  
  
  CONCLUSIONS
  Log-rank test, Cox regression, or other analytical methods could be used to assess agreement in quantitative variables; correct interpretations require good clinical sense.
authors.affiliation: Division of Preventive Medicine and Public Health, School of Medicine, University of Cantabria, Avda. Cardenal Herrera Oria s/n, 39011 Santander, Spain. llorcaj@unican.es
authors.forename: Javier
authors.initials: J
authors.lastname: Llorca
authors.forename: Miguel
authors.initials: M
authors.lastname: Delgado-Rodríguez
mesh_terms: D015982:Bias; D002097:C-Reactive Protein / Q000032:analysis; D006801:Humans; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D016019:Survival Analysis
chemical_list: D002097:C-Reactive Protein