Background and Purpose A response-adaptive randomization (RAR) trial design actively adjusts the ratio of participants assigned to each trial arm favoring the better performing treatment by using outcome data from participants already in the trial. form and having questions answered subjects indicated whether they would consent to the trial. 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 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. Trial designs were generally well understood by the participants. Conclusions The hypothetical RAR trial attracted more research participation than standard randomization. RAR has the potential to increase recruitment and offer benefit to future trial Mouse monoclonal to MYL3 participants. Keywords: Response adaptive randomization acute stroke emergency medicine tPA clinical trials consent Introduction In time sensitive emergency conditions participation in research is limited. Medical care should aim to provide the best possible care for that individual; however it is important to balance this with research goals of gathering unbiased data regarding the effect of treatment. In standard two-arm clinical trial designs each participant has an equal but random chance of receiving either treatment. Response-adaptive randomization (RAR) is one way to address the tension between the medical and research aims.1 In a trial utilizing RAR the ratio of participants assigned to each study group is adjusted based on accumulating data while the study is ongoing using a predetermined defined set of rules. This works SL251188 to collectively favor the patients within the trial in situations when one treatment is ultimately better than the other. There is limited knowledge on the extent of use and effectiveness of RAR study designs in the emergency setting. However some studies have assessed willingness to join research studies in emergency conditions such as ischemic stroke or subarachnoid hemorrhage. These studies have shown that just over half of participants or their proxies consent to research.2 3 Hesitation to join emergency research studies was attributed to the perceived risk of such trials and preexisting negative attitudes toward research.3 Participation in emergency care research may be unattractive to a significant proportion of patients. The influence of trial design on research participation in emergency care has not previously been studied. Therefore we hypothesized that a hypothetical acute stroke trial which included RAR would be more agreeable to participants than a trial using fixed 1:1 randomization with all other aspects of the trial design presented exactly the same. Methods A more detailed description of the methods is available as supplemental methods online. Briefly we performed a cross-sectional study of non-critically ill emergency department adult patients without presenting symptoms consistent with stroke altered mental status or alcohol intoxication. Participants were introduced to the study gave consent and were randomly allocated to see one of two videos. They also answered questions about demographics and stroke symptom knowledge. The video was the same across both groups with the exception of the explanation of the hypothetical study: either described as a standard clinical trial or a response-adaptive SL251188 randomization study. The RAR video can be viewed at http://youtu.be/cKIWduCaPZc; the standard trial video can be viewed at http://youtu.be/SrI4FdCTZ-A. All participants in both groups were informed that the trial had recruited approximately one half of the total planned enrollment and then were asked if SL251188 they would participate in the stroke trial (primary outcome). SL251188 Statistical analysis was performed using SPSS Version 19. The entire protocol was placed online prior to the analysis or visualization of the data (http://bit.ly/11gTfLU). All hypothesis and main analyses were pre-specified prior to any visualization of participant reactions. We carried out stratified analyses based on participant understanding based on post-hoc review of the results. Ethics This.