Outcome measures in acute stroke trials - A systematic review and some recommendations to improve practice

Background-There is little consistency in the measurement of outcome in acu te stroke trials, and this may complicate interpretation of the results and reduce the likelihood of detecting worthwhile drug effects. This study aim s to investigate empirically the measures used to date and to give recommen dations for future studies. Summary of Comment-A systematic review of all published randomized studies of acute stroke drug intervention was undertaken, and the measures used wer e recorded. Fifty-one studies involving 57 214 subjects were identified. Th ese studies used 14 different measures of impairment, II different measures of activity, 1 measure of "quality of life," and s miscellaneous other mea sures. Timing of outcome assessments varied from 1 week to 1 year, with the modal time being 3 months. Many studies used ordinal measures but dichotom ized results for analysis. Of the 51 studies included in the review, only 2 1 demonstrated benefit with the defined primary outcome measure. In several studies, however, post hoc analysis using varied outcome measures or varie d cut points for dichotomizing outcomes resulted in positive results, where as the primary study analysis failed to do so. Conclusions-There is no consensus on the level of outcome to be used, the m ethod of measurement to be used, or the most appropriate timing of the asse ssment. It is recommended that future studies should include extended/instr umental activities and advanced mobility as components of the primary outco me measure, with outcome assessment being undertaken at 6 months. New initi atives in developing stroke-specific outcomes may address some of the curre nt problems in the assessment of stroke outcomes.