How baseline severity affects efficacy and safety outcomes in acute ischemic stroke intervention trials.

Baseline severity of stroke may be an important predictor of efficacy and safety outcomes in acute stroke intervention trials. This summary explores definitions of baseline variables and outcomes used to measure stroke severity, efficacy, and safety. In addition, the discussion here reviews select acute ischemic stroke intravenous thrombolytic studies, such as the National Institute of Neurological Disorders and Stroke rt-PA Stroke Study and European Cooperative Acute Stroke Studies, select neuroprotectant and endovascular clot retrieval device studies, and large cooperative databases, such as the Virtual International Stroke Trials Archive and Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Registry, to explore relationships between baseline stroke severity and other possible factors associated with efficacy and safety outcomes. The NIH Stroke Scale and modified Rankin scale will be featured as major stroke outcome measures, based on frequency of use and reliability, familiarity, adaptability, and comparability.