Open AccessResist the Temptation of Response-Adaptive Randomization
Author(s) -
Michael A. Proschan,
Scott Evans
Publication year - 2020
Publication title -
clinical infectious diseases/clinical infectious diseases (online. university of chicago. press)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.44
H-Index - 336
eISSN - 1537-6591
pISSN - 1058-4838
DOI - 10.1093/cid/ciaa334
Subject(s) - randomization , medicine , inefficiency , temptation , selection bias , blinding , clinical trial , randomized controlled trial , sample size determination , intensive care medicine , statistics , surgery , psychology , mathematics , pathology , social psychology , microeconomics , economics
Response-adaptive randomization (RAR) has recently gained popularity in clinical trials. The intent is noble: minimize the number of participants randomized to inferior treatments and increase the amount of information about better treatments. Unfortunately, RAR causes many problems, including (1) bias from temporal trends, (2) inefficiency in treatment effect estimation, (3) volatility in sample-size distributions that can cause a nontrivial proportion of trials to assign more patients to an inferior arm, (4) difficulty of validly analyzing results, and (5) the potential for selection bias and other issues inherent to being unblinded to ongoing results. The problems of RAR are most acute in the very setting for which RAR has been proposed, namely long-duration "platform" trials and infectious disease settings where temporal trends are ubiquitous. Response-adaptive randomization can eliminate the benefits that randomization, the most powerful tool in clinical trials, provides. Use of RAR is discouraged.