title: Optimizing the use of expert panel reference diagnoses in diagnostic studies of multidimensional syndromes.
abstract: BACKGROUND
  In the absence of a gold standard, a panel of experts can be invited to assign a reference diagnosis for use in research. Available literature offers limited guidance on assembling and working with an expert panel for this purpose. We aimed to develop a protocol for an expert panel consensus diagnosis and evaluated its applicability in a pilot project.
  
  
  METHODS
  An adjusted Delphi method was used, which started with the assessment of clinical vignettes by 3 experts individually, followed by a consensus discussion meeting to solve diagnostic discrepancies. A panel facilitator ensured that all experts were able to express their views, and encouraged the use of argumentation to arrive at a specific diagnosis, until consensus was reached by all experts. Eleven vignettes of patients suspected of having a primary neurodegenerative disease were presented to the experts. Clinical information was provided stepwise and included medical history, neurological, physical and cognitive function, brain MRI scan, and follow-up assessments over 2 years. After the consensus discussion meeting, the procedure was evaluated by the experts.
  
  
  RESULTS
  The average degree of consensus for the reference diagnosis increased from 52% after individual assessment of the vignettes to 94% after the consensus discussion meeting. Average confidence in the diagnosis after individual assessment was 85%. This did not increase after the consensus discussion meeting. The process evaluation led to several recommendations for improvement of the protocol.
  
  
  CONCLUSIONS
  A protocol for attaining a reference diagnosis based on expert panel consensus was shown feasible in research practice.
authors.forename: Ron L H
authors.initials: RL
authors.lastname: Handels
authors.forename: Claire A G
authors.initials: CA
authors.lastname: Wolfs
authors.forename: Pauline
authors.initials: P
authors.lastname: Aalten
authors.forename: Patrick M M
authors.initials: PM
authors.lastname: Bossuyt
authors.forename: Manuela A
authors.initials: MA
authors.lastname: Joore
authors.forename: Albert F G
authors.initials: AF
authors.lastname: Leentjens
authors.forename: Johan L
authors.initials: JL
authors.lastname: Severens
authors.forename: Frans R J
authors.initials: FR
authors.lastname: Verhey
mesh_terms: D003697:Delphi Technique; D006801:Humans; D019636:Neurodegenerative Diseases / Q000175:diagnosis*; D010865:Pilot Projects; D013577:Syndrome