AUTHOR=Truzoli Roberto , Reed Phil , Osborne Lisa A. 

TITLE=Patient Expectations of Assigned Treatments Impact Strength of Randomised Control Trials

JOURNAL=Frontiers in Medicine

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.648403

DOI=10.3389/fmed.2021.648403

ISSN=2296-858X

ABSTRACT=Patient engagement with treatments potentially poses problems for interpreting the results and meaning of Randomised Control Trials (RCTs). If a patient is assigned to a treatment that does, or does not, match their expectations, and this impacts their motivation to engage with that treatment, it will affect the distribution of outcomes. In turn, this will impact the obtained power and error rates of RCTs.  Simple Monte Carlo simulations demonstrate that these patient variables affect sample variance, and sample kurtoses. These effects reduce the power of RCTs, and may lead to false negatives, even when the randomisation process works, and equally distributes those with positive and negative views about a treatment to an arm.