Outcome measures in acute stroke trials: a systematic review and some recommendations to improve practice

There is little consistency in the measurement of outcome in acute stroke trials, and this may complicate interpretation of the results and reduce the likelihood of detecting worthwhile drug effects. This study aims to investigate empirically the measures used to date and to give recommendations for future studies.

A systematic review of all published randomized studies of acute stroke drug intervention was undertaken, and the measures used were recorded. Fifty-one studies involving 57 214 subjects were identified. These studies used 14 different measures of impairment, 11 different measures of activity, 1 measure of "quality of life," and 8 miscellaneous other measures. Timing of outcome assessments varied from 1 week to 1 year, with the modal time being 3 months. Many studies used ordinal measures but dichotomized results for analysis. Of the 51 studies included in the review, only 21 demonstrated benefit with the defined primary outcome measure. In several studies, however, post hoc analysis using varied outcome measures or varied cut points for dichotomizing outcomes resulted in positive results, whereas the primary study analysis failed to do so.

There is no consensus on the level of outcome to be used, the method of measurement to be used, or the most appropriate timing of the assessment. It is recommended that future studies should include extended/instrumental activities and advanced mobility as components of the primary outcome measure, with outcome assessment being undertaken at 6 months. New initiatives in developing stroke-specific outcomes may address some of the current problems in the assessment of stroke outcomes