Integrating an evidence-based assessment of benefit and risk in disease-modifying treatment of multiple sclerosis.

BACKGROUND: As results from an increasing number of clinical trials with disease-modifying drugs (DMDs) in multiple sclerosis (MS) become available, the challenge for the treating neurologist is how to decide on the appropriate therapy for an individual patient. OBJECTIVE: An International Working Group for Treatment Optimization in MS met to consider how the principles of evidence-based medicine (EBM) should be used to assess the current best evidence regarding the treatment of MS. This report summarizes the outcome from the workshop at which this topic was addressed. RESULTS: Class I evidence from head-to-head studies provides the best tool for direct comparisons of DMDs. However, other EBM approaches to data analysis from placebo-controlled trials can be used to help determine the benefits and risks of a particular DMD relative to placebo by calculating the number needed to treat to achieve a positive outcome, such as avoiding a relapse, and the number needed to harm to produce an additional adverse event, such as having a therapy-related dropout. This provides a structured basis for comparisons between DMDs. CONCLUSION: While such comparisons have their limitations, particularly when drugs with substantially different side-effect profiles are to be compared, they can provide useful information to guide treatment decisions.