The uncertainty period preceding the clinical defined SPMS diagnosis and the applicability of objective classifiers - A Danish single center study.

Our findings emphasize the uncertainty related to the transition from RRMS to SPMS illustrating the need of an improved diagnostic approach. Objective classifiers might have the potential to help reduce the period of diagnostic uncertainty in the future, but in their current form they do not perform satisfactorily enough to solve all difficulties related to detecting SPMS-transition.