The value of nonfactual information in distinguishing primary from secondary headache disorders results of a Delphi study. - Pohl, Heiko; Do, Thien Phu; Gantenbein, Andreas R.; Genç, Hamit; Kristoffersen, Espen Saxhaug; Hansen, Jakob Møller; Portes Souza, Marcio Nattan; Obermann, Mark; Grosu, Oxana; Navarro Pérez, María Pilar; Romozzi, Marina; Schankin, Christoph; et al. (Cephalalgia Reports, 2026)