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Mitigating and Quantifying Cherry-Picking in Acute Stroke Trials
Mayank Goyal1, Aravind Ganesh1
1Departments of Clinical Neurosciences, Community Health Sciences, and Radiology, Calgary Stroke Program, and the Hotchkiss Brain Institute, University of Calgary Cumming School of Medicine, AB, Canada.
Insights
Selective patient recruitment, or cherry-picking, in clinical trials compromises results. This study identifies causes, detection methods, and mitigation strategies to improve trial validity and generalizability.
Area of Science:
- Clinical Trials
- Medical Research Methodology
- Health Services Research
Background:
- Consecutive patient enrollment is crucial for the internal and external validity of randomized controlled trials (RCTs).
- Non-representative patient populations in trials, often due to selective recruitment (cherry-picking), undermine the generalizability of findings.
- Treatment of eligible patients outside the trial setting can lead to biased participant selection.
Purpose of the Study:
- To discuss the problem of patient cherry-picking in clinical trials.
- To explore factors contributing to cherry-picking, including investigator incentives.
- To examine strategies for identifying and mitigating cherry-picking to enhance trial validity.
Main Methods:
- Review of factors contributing to selective patient recruitment in clinical trials.
- Critical examination of strategies to identify and mitigate patient cherry-picking.
- Proposal of a quantitative method to assess cherry-picking in acute stroke trials, differentiating it from underrecruitment.
Main Results:
- Selective recruitment (cherry-picking) poses a significant threat to the validity and generalizability of randomized controlled trials.
- Investigator incentives (e.g., the 'What's In It For Us' problem) can contribute to cherry-picking.
- Quantifying cherry-picking is essential for developing effective mitigation strategies.
Conclusions:
- Addressing patient cherry-picking is vital for strengthening the internal and external validity of randomized controlled trials.
- Developing and implementing methods to quantify cherry-picking will facilitate meaningful progress in resolving this issue.
- Improved recruitment strategies will enhance the reliability and applicability of clinical trial outcomes.
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.
