Composite Scores and Other Outcome Measures in Stroke Trials

Randomized controlled trials represent the most useful tool to evaluate the effectiveness of a treatment in medical research. When designing a clinical trial, the choice of end points, assessment tools, and scores is crucial as they represent the prerequisites for the evaluation of outcomes and for the critical appraisal of findings.

In stroke research, outcomes are mainly represented by composite end points focusing on the occurrence of cardiovascular and cerebrovascular events in trials on primary and secondary prevention and by measures of recovery and residual disability in acute stroke trials. Assessment tools which are more frequently used to evaluate recovery after acute stroke care include the National Institutes of Health Stroke Scale, the Modified Rankin Scale, the Barthel Index, the Glasgow Outcome Scale, and the Stroke Impact Scale. However, there is a wide heterogeneity of outcome measures across different trials, which makes it difficult to compare results and to draw definitive conclusions on the usefulness of the investigated strategies and treatments. Moreover, in some cases, details about outcomes are poorly reported with a tendency to focus on outcomes that are statistically significant while information about nonsignificant outcomes is frequently missed.

There is an urgent need to improve the quality of designing, conducting, analyzing, and reporting data from randomized clinical trials in order to obtain complete, clear, and rigorous information on the effectiveness of management strategies in stroke care. Key properties of tools measuring outcome should include validity, reliability, and convenient statistical characteristics.