Answer： 借鉴2008年美国FDA发布的Date Retention When Subjects withdraw FDA-regulated Clinical Trials （http://www.fda.gov/downloads/regulatoryinformation/guidances/ucm126489.pdf），基于临床研究的科学性和伦理性两方面考虑，提出的建议如下：“data collected on study subjects up to the time of withdrawal must remain in the trial database in order for the study to be scientifically valid. If a subject withdraws from a study, removal of already collected data would undermine the scientific, and therefore the ethical integrity of the research. Such removal of data could also put enrolled subjects, and eventual users of marketed products at an unreasonably risk …”。因此，在知情同意告知信息中，对于用于疗效和安全分析而在研究过程中采集的样本，应明确告知受试者，在受试者退出研究后，可能会继续使用﹑处理和共享已收集的信息。 但对于受试者单独签署的同意样本储存并用于探索性研究或其他研究的知情同意书，应明确告知受试者可随时撤回同意。当受试者撤销同意时，留存的该受试者样本应予以销毁而不再进行检测。