Practicing Evidence-Based Stroke Medicine.

The practice of evidence-based medicine depends on several steps: a basic science derived understanding of disease pathophysiology, epidemiological research, and the results of well-conducted and appropriately analyzed randomized clinical trials (RCTs). The approval of new therapies by regulatory agencies is also based largely on RCT determination of the safety and therapeutic efficacy of drugs and devices. Once a new therapy is approved for use in clinical practice, clinicians typically begin to use it in a manner which mirrors the clinical trial design, for example, in the population for who risk and benefit have been established. It must be acknowledged that in the United States and in other countries, clinicians have leeway in their therapeutic decision making and it is not uncommon for therapies to be used for situations not tested in the RCTs that led to approval, the so-called off-label use. The off-label use of stroke-related therapies is relatively common, and we will consider the appropriateness of doing this in 3 common clinical scenarios.