Mitigating and Quantifying Cherry-Picking in Acute Stroke Trials.

Abstract

Consecutive enrollment of eligible patients is fundamental to the internal and external validities of randomized controlled trials. The generalizability of trial results is greatly undermined when enrolled patients are not representative of the broader target population, which is especially likely if a large proportion of otherwise-eligible individuals receive treatment outside the trial. In this article, we discuss the problem that such selective recruitment or cherry-picking of patients poses to clinical trials. We explore factors contributing to such cherry-picking, such as the What's In It For Us problem for subinvestigators, and discuss strategies to identify when cherry-picking is going on in a trial. We also critically examine various strategies to mitigate cherry-picking. Moreover, we propose a method to quantify cherry-picking within an acute stroke trial while distinguishing it from simple underrecruitment. It is only when we seek to consistently quantify the problem of cherry-picking, that we will make meaningful strides toward resolving this issue and further strengthening the validity of our randomized controlled trials.