Tomas Kalincik, Head of the Clinical Outcomes Research Unit at the University of Melbourne, and Maria Pia Sormani, Professor of Biostatistics at the University of Genoa, discuss the use of real-world data to compare disease-modifying treatments (DMTs) in multiple sclerosis, including the advantages and limitations of randomised control trials and observational studies. Hosted by Alan Thompson, Editor-in-Chief of the MS Journal and Professor at University College London.