Development of a diagnostic checklist to identify functional cognitive disorder versus other neurocognitive disorders
Verónica Cabreira, Jane Alty, Sonja Antić, Rui Araújo, Selma Aybek, Harriet A. Ball, Gaston Baslet, Rohan Bhome, Jan Coebergh, Bruno Dubois, Mark J. Edwards, Saša R. Filipović, Kristian Steen Frederiksen, Thomas Harbo, Brad Hayhow, Robert Howard, Jonathan Huntley, Jeremy D. Isaacs, Curt LaFrance, A. J. Larner, Francesco Di Lorenzo, James Main, Elizabeth Mallam, Camillo Marra, João Massano, Emer R. McGrath, Isabel Moreira, Flavio Nobili, Suvankar Pal, Catherine Pennington, Miguel Tábuas‐Pereira, David L. Perez, Stoyan Popkirov, Dane Rayment, Martin N. Rossor, Mirella Russo, Isabel Santana, Jonathan M. Schott, Emmi P. Scott, Ricardo Taipa, Tiago Teodoro, Michèle Tinazzi, Svetlana Tomić, Sofia Toniolo, Caroline Winther Tørring, Tim Wilkinson, Martin Zeidler, Lisbeth Frostholm, Laura McWhirter, Jon Stone, Alan Carson
Abstract
Background: Functional cognitive disorder (FCD) poses a diagnostic challenge due to its resemblance to other neurocognitive disorders and limited biomarker accuracy. We aimed to develop a new diagnostic checklist to identify FCD versus other neurocognitive disorders. Methods: The clinical checklist was developed through mixed methods: (1) a literature review, (2) a three-round Delphi study with 45 clinicians from 12 countries and (3) a pilot discriminative accuracy study in consecutive patients attending seven memory services across the UK. Items gathering consensus were incorporated into a pilot checklist. Item redundancy was evaluated with phi coefficients. A briefer checklist was produced by removing items with >10% missing data. Internal validity was tested using Cronbach's alpha. Optimal cut-off scores were determined using receiver operating characteristic curve analysis. Results: A full 11-item checklist and a 7-item briefer checklist were produced. Overall, 239 patients (143 FCD, 96 non-FCD diagnoses) were included. The checklist scores were significantly different across subgroups (FCD and other neurocognitive disorders) (F(2, 236)=313.3, p<0.001). The area under the curve was excellent for both the full checklist (0.97, 95% CI 0.95 to 0.99) and its brief version (0.96, 95% CI 0.93 to 0.98). Optimal cut-off scores corresponded to a specificity of 97% and positive predictive value of 91% for identifying FCD. Both versions showed good internal validity (>0.80). Conclusions: This pilot study shows that a brief clinical checklist may serve as a quick complementary tool to differentiate patients with neurodegeneration from those with FCD. Prospective blind large-scale validation in diverse populations is warranted.Cite Now.