title: Is it time to use observational data to estimate treatment effectiveness in multiple sclerosis?
authors.forename: Dennis E
authors.initials: DE
authors.lastname: Wilkins
mesh_terms: D015982:Bias; D006801:Humans; D009103:Multiple Sclerosis / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D012107:Research Design / Q000592:standards*