The Argentinean multiple sclerosis registry (RelevarEM): Methodological aspects and directions

•No ongoing nationwide registry exists in Latin America.•We describe the methodology behind RelevarEM, the first nationwide MS registry in Argentina and LATAM.•The structure, ethical aspects, implementation and variables of the registry are described.•RelevarEM has the objective of providing reliable real-world data of MS in Argentina and LATAM. Despite that different registries already exist in various countries in Europe and North America, no ongoing nationwide registry exists in Latin America (LATAM), a region where the disease behaves differently than in other regions. The objective of this document is to describe the methodology behind RelevarEM, the first nationwide MS registry in Argentina and LATAM. In this article, we described the creation, implementation and data management of the nationwide MS registry in Argentina. The registry contains information on the structure, ethical aspects, implementation and variables of the registry (Clinical Trials registry number NCT NCT03375177). RelevarEM is the first MS nationwide registry in Argentina, as well as in LATAM, with the objective of providing reliable real-world data of MS in the country.