University of Melbourne - Neuroepidemiology Unit, Oxford Brookes University, Deakin University, Swansea University - UK MS Register, Imperial College London - Faculty of Medicine, University of Melbourne - Neuroepidemiology Unit, University of Wollongong, affiliation not provided to SSRN, University of Melbourne - Centre for Epidemiology and Biostatistics, affiliation not provided to SSRN and Oxford Brookes University