Response-adaptive randomization in clinical trials

AIM: To introduce the response-adaptive randomization,which is one of the randomization strategies in clinical trials.METHODS: The ideas and theories of the play-the-winner rule and randomized-play-the-winner rule,which are two procedures of response-adaptive randomization,are introduced.A simulation study is employed to compare response-adaptive randomization with traditional equal-probability allocation.The advantages and disadvantages of the randomization rules and the issues concerned in implementation of response-adaptive randomization are discussed.RESULTS: The results show that the response-adaptive randomization reduce the number of failures with little decrease in test power than in the case of traditional equal-probability allocation.CONCLUSION: The play-the-winner rule and randomized-play-the-winner rule deserve the attention of clinicians and statisticians and are suggested in clinical trials after a certain degree of improvement since it is better balanced of the issues between ethics and statistics.