Urn-based response adaptive procedures and optimality

作者：Bhattacharya Rahul^*

来源：Drug Information Journal, 2008, 42(5): 441-448.

• urn model
• odds ratio
• optimality

In most of the two-treatment clinical trials, patients are randomized to either treatment in a balanced fashion, and at the end of the experiment a decision is made as to which treatment is more effective. But such a strategy of finding the effective treatment by assigning half of the subjects to the inferior treatment locks ethical imperative. Urn-based allocation procedures are often used as better alternatives for their ability to use the accrued patient outcomes to sensibly adjust the allocation of the future subjects. However, these designs leave the final goal (may be maximization of power or minimization of overall failures) unexplained to date. This unexplained ultimate goal or optimality of the useful urn designs is established considering odds ratio as the measure of effect. A comparative study of the performance based on both simulated and real-life data is provided.

• 出版日期2008