Perils and pitfalls in the interpretation of clinical trials: A reflectionon the recent experience in multiple sclerosis

Therapeutic trials in multiple sclerosis, in part because of the marked int ra- and interindividual variability of its clinical course, are prone to se rious flaws in both design and interpretation. As a consequence, it has bee n a common historical pattern that treatment regimens, which are enthusiast ically recommended at one point in time, are later proven to be ineffective by more definitive studies. This review considers several recently publish ed therapeutic trials in order to exemplify some of the difficulties that c ommonly arise in this area of clinical research.