Observatoire Français de la Sclérose en Plaques (OFSEP): A unique multimodal nationwide MS registry in France.

The care of multiple sclerosis (MS) in France is based on two complementary interlinked networks: MS expert centers in university hospitals and regional networks of neurologists. The routine use of European database for multiple sclerosis (EDMUS) in all those centers has paved the way for the constitution of a national registry, designated as Observatoire Français de la Sclérose En Plaques (OFSEP). It promotes a prospective, standardized, high-quality, and multimodal collection of data. On June 2018, there were 68.097 files, with 71.1% females, representing 761,185 person-years. This huge database is open to the scientific community and might contribute exploring unresolved issues and unmet needs in MS.