Responsiveness of outcome measures used in an antidementia drug trial

The responsiveness of outcome measures used in antidementia drug trials has had little formal analysis, but it can be crucial to the interpretation of a medication's effectiveness. The authors report the responsiveness of outcome measures from the Canadian trial of linopirdine, a novel phenylinodolinone, estimated using an effect size statistic. The effect sizes ranged from 0.10-0.26, with the cognitive and functional measures yielding estimates greater than 0.20, a level held to be clinically detectable. All of the standard measures used in this trial, save one, performed better than the global clinical measure. The global clinical measure used in this study may have been too insensitive to detect minimal clinical change.