Methodology and application of adaptive and sequential approaches in contemporary clinical trials

The clinical trial,a prospective study to evaluate the effect of interventions in humans under prespecified conditions,is a standard and integral part of modern medicine. many adaptive and sequential approaches have been proposed for use in clinical trials to allow adaptations or modifications to aspects of a trial after its initiation without undermining the validity and integrity of the trial. the application of adaptive and sequential methods in clinical trials has significantly improved the flexibility,efficiency,therapeutic effect,and validity of trials. to further advance the performance of clinical trials and convey the progress of research on adaptive and sequential methods in clinical trial design,we review significant research that has explored novel adaptive and sequential approaches and their applications in phase i,ii,and iii clinical trials and discuss future directions in this field of research. © 2012 zhengjia chen et al.