From the University of Michigan Medical School, Ann Arbor (J.S.T.); and Department of Emergency Medicine (W.J.M.) and Department of Neurology (W.J.M.), University of Michigan Health System, Ann Arbor.
Stroke. 2014 Jul;45(7):2131-3. doi: 10.1161/STROKEAHA.114.005418. Epub 2014 Jun 10.
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. Compared with a standard clinical trial, an RAR study design has the potential to improve patient participation in acute stroke trials.
This cross-sectional randomized survey included adult emergency department patients, age≥18, without symptoms of stroke or other critical illness. A standardized protocol was used, and subjects were randomized to 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. A multivariable logistic regression model was fitted to estimate the impact of RAR while controlling for demographic factors and patient understanding of the design.
A total of 418 subjects (210 standard and 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% confidence interval, 3.7-22.2). The RAR group had a higher odds ratio of agreeing to research (odds ratio, 1.89; 95% confidence interval, 1.2-2.9) while adjusting for patient level factors. Trial designs were generally well understood by the participants.
The hypothetical RAR trial attracted more research participation than standard randomization. RAR has the potential to increase recruitment and offer benefit to future trial participants.
响应适应性随机化（RAR）试验设计通过使用已经参与试验的参与者的结果数据，积极调整分配给每个试验臂的参与者的比例，有利于表现更好的治疗方法。与标准临床试验相比，RAR 研究设计有可能提高急性中风试验中患者的参与度。
本横断面随机调查纳入了年龄≥18 岁、无中风或其他急危重症症状的成年急诊患者。使用标准化方案，将患者随机分配至 RAR 或标准假设性急性中风试验组。在观看描述假设性试验的视频（http://youtu.be/cKIWduCaPZc）、查看知情同意书并回答问题后，患者表示是否同意参加试验。采用多变量逻辑回归模型来估计 RAR 的影响，同时控制人口统计学因素和患者对设计的理解。
共纳入 418 例患者（210 例标准组和 208 例 RAR 组）。两组基线特征均均衡。RAR 试验的参与率（67.3%）明显高于标准试验（54.5%），绝对增加：12.8%（95%置信区间，3.7-22.2）。在调整患者个体因素后，RAR 组同意研究的可能性更高（比值比，1.89；95%置信区间，1.2-2.9）。参与者对试验设计总体理解较好。
假设性 RAR 试验比标准随机化试验吸引了更多的研究参与。RAR 有可能增加招募人数，并为未来的试验参与者带来益处。
