Verbal Labels Can Triple Perceived Risk in Clinical Trials

Abstract

The purpose of this study was to assess whether the use of verbal descriptors, such as “common” and “rare” affects peoples perceptions of the risks involved in clinical trials as well as their likelihood of entering into the trial. Participants were required to imagine that they had a serious skin condition and being asked if they would take part in a clinical trial for a new drug. They were provided with some information about the trial and drug, in which the probability of side effects occurring was described using either verbal labels alone or verbal labels with associated numerical values. The results showed that those given just the verbal descriptors were significantly less satisfied with the information, perceived risk to be higher (by a factor of three) and benefit to health to be lower, and indicated that they would be significantly less likely to enter the trial. We recommend that patients are informed about the likelihood of potential risks using verbal terms linked with indicative frequency ranges

Keywords

Risk communication Medicine side effects Adverse events Patient information Clinical trials Informed consent

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