Abstract 128: Can Response Adaptive Randomization Increase Participation in Acute Stroke Trials?
Introduction: Acute stroke trials may be improved by using response-adaptive randomization (RAR) because it works in favor of the trial population on average. With RAR, the ratio of participants assigned to each trial arm is adjusted to favor the better performing treatment using outcome information from earlier participants in the clinical trial.
Hypothesis: When presented a hypothetical acute stroke trial, more patients would agree to a RAR versus a standard clinical trial with all other aspects of trial held constant.
Methods: This cross-sectional survey included adult ED patients presenting without stroke or other critical illness. A standardized protocol was used and subjects were randomized to view either an RAR or standard hypothetical acute stroke trial. After viewing the video describing the hypothetical trial (http://youtu.be/cKIWduCaPZc), reviewing the consent form, and having questions answered, subjects indicated whether they would consent to the trial. Adequacy of the informed consent process was measured by ICQ-4. A multivariable logistic regression model was fitted to estimate the impact of RAR, while controlling for demographic factors and patient understanding of the design.
Results: A total of 418 subjects (210 standard 208 RAR) were enrolled. All baseline characteristics were balanced between groups. There was significantly higher participation in the RAR trial (67.3%) versus the standard trial (54.5%), absolute increase: 12.8% (95% CI: 3.7 to 22.2%). The trials were generally well understood by the participants (Table); however standard randomization appeared to be better understood. The RAR group had a higher odds ratio of agreeing to research (O.R. 1.89, 95% CI [1.2 - 2.9]), while adjusting for patient level factors.
Conclusion: The RAR trial attracted more research participation than standard randomization and has potential to increase recruitment and offer benefit to future trial participants.
- © 2012 by American Heart Association, Inc.