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. Conclusion: A protocol for attaining a reference diagnosis based on expert panel consensus was shown feasible in research practice.

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Keywords Reference diagnosis, Consensus panel, Delphi, Gold standard, Diagnostic validation, Incorporation bias, Multidimensional syndromes, Alzheimer’s disease
Persistent URL dx.doi.org/10.1186/s12883-014-0190-3, hdl.handle.net/1765/77127
Journal BMC Neurology
Handels, R.L, Wolfs, C.A.G, Aalten, P, Bossuyt, P.M.M, Joore, M.A, Leentjens, A.F. G, … Verhey, F.R.J. (2014). Optimizing the use of expert panel reference diagnoses in diagnostic studies of multidimensional syndromes. BMC Neurology, 14(1), 1–9. doi:10.1186/s12883-014-0190-3