title: Objective consensus from decision trees.
abstract: BACKGROUND
  Consensus-based approaches provide an alternative to evidence-based decision making, especially in situations where high-level evidence is limited. Our aim was to demonstrate a novel source of information, objective consensus based on recommendations in decision tree format from multiple sources.
  
  
  METHODS
  Based on nine sample recommendations in decision tree format a representative analysis was performed. The most common (mode) recommendations for each eventuality (each permutation of parameters) were determined. The same procedure was applied to real clinical recommendations for primary radiotherapy for prostate cancer. Data was collected from 16 radiation oncology centres, converted into decision tree format and analyzed in order to determine the objective consensus.
  
  
  RESULTS
  Based on information from multiple sources in decision tree format, treatment recommendations can be assessed for every parameter combination. An objective consensus can be determined by means of mode recommendations without compromise or confrontation among the parties. In the clinical example involving prostate cancer therapy, three parameters were used with two cut-off values each (Gleason score, PSA, T-stage) resulting in a total of 27 possible combinations per decision tree. Despite significant variations among the recommendations, a mode recommendation could be found for specific combinations of parameters.
  
  
  CONCLUSIONS
  Recommendations represented as decision trees can serve as a basis for objective consensus among multiple parties.
authors.affiliation: Department of Radiation Oncology, Kantonsspital St. Gallen, Rorschacherstr. 95, 9007, St. Gallen, Switzerland. paul.putora@kssg.ch.
authors.forename: Paul Martin
authors.initials: PM
authors.lastname: Putora
authors.affiliation: Department of Radiation Oncology, Kantonsspital St. Gallen, Rorschacherstr. 95, 9007, St. Gallen, Switzerland. cedric.panje@kssg.ch.
authors.forename: Cedric M
authors.initials: CM
authors.lastname: Panje
authors.affiliation: Department of Radiation Oncology, University Hospital Basel, Basel, Switzerland. palex80@yahoo.com.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Papachristofilou
authors.affiliation: Department of Radiation Oncology, Inselspital, University Hospital Bern, Bern, Switzerland. alan.dalpra@insel.ch.
authors.forename: Alan
authors.initials: A
authors.lastname: Dal Pra
authors.affiliation: Department of Neurology and Haematology & Oncology, Kantonsspital St. Gallen, St. Gallen, Switzerland. thomas.hundsberger@kssg.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hundsberger
authors.affiliation: Department of Radiation Oncology, Kantonsspital St. Gallen, Rorschacherstr. 95, 9007, St. Gallen, Switzerland. ludwig.plasswilm@kssg.ch.
authors.forename: Ludwig
authors.initials: L
authors.lastname: Plasswilm
mesh_terms: D032921:Consensus; D003663:Decision Trees; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D018787:Radiation Oncology / Q000379:methods*