Measuring misconception in clinical trials

Tool could help show whether participant understands difference between research and treatment

Therapeutic misconception in clinical trials continues to be a significant concern for researchers and IRBs. Studies have shown that misunderstandings persist about the therapeutic value of research interventions among participants and even among research staff.

Now, a new screening tool has been developed to measure therapeutic misconception. The hope is that the tool can be used not just to screen potential research participants, but to aid further research on the phenomenon itself: What factors lead people to hold inaccurate or overly optimistic ideas about research? In what types of studies does it occur most frequently?

"We would like to see it used across disease conditions and phases of clinical trial research, to tease apart where this phenomenon is more likely to appear than others," says Norm O'Rourke, PhD, RPsych, an associate professor and clinical psychologist at Simon Fraser University in Vancouver, British Columbia. O'Rourke's student, Pak Hei Benedito Chou, developed the tool as part of his master's thesis.

O'Rourke says there have been previous screening tools for therapeutic misconception, but they tend to be too long for use in clinical trials. In addition, he says, Chou's tool takes into account more recent work that defines therapeutic misunderstanding in a more nuanced way.

Three facets

That work, by Sam Horng and Christine Grady at the National Institutes of Health, identified three facets of therapeutic misunderstanding, all of which may contribute to research subjects' incorrect beliefs about participation in clinical trials:

—Therapeutic misconception, the tendency to conflate research and clinical treatment because the subject doesn't understand research methodology;

—Therapeutic misestimation, a subject's unrealistic estimation of risks and benefits, for example if a participant doesn't understand the odds of being assigned to a placebo in a study;

—Therapeutic optimism, in which a subject understands these other factors but continues to be overly optimistic about the potential for benefit from a trial.

"A person may well understand that there's a 50-50 chance that they'll be taking a placebo, but they choose to believe that they're taking active medication," he says. "Or there's a 5 percent chance that this will have any therapeutic benefit, but they assume, even with an understanding of that information, that they'll be part of that 5 percent."

Therapeutic optimism is not necessarily a problem for a research participant, O'Rourke says.

"Optimism in fact can be quite health inducing, both mentally and physically," he says. "Positive illusions seem to be positively associated with physical as well as mental health outcomes."

He says that Chou's inclusion of a measurement of therapeutic optimism in his screening tool can help differentiate between people who fundamentally don't understand that they're participating in research and people who do, but who choose to be hopeful about their prospects.

"One reason why I think the scale may be good as far as moving the field forward is that it captures this concept," O'Rourke says. "Misestimation and misconception are measured as well as positive optimism."

The screening tool asks the participant to imagine being asked to participate in a clinical trial. A short paragraph describes concepts such as research vs. treatment and randomization. Participants are then asked whether they agree with 20 statements such as these:

— "The main reason that people will be recruited for this study is so that they can benefit from the special treatment in this research project."

—"Taking part in this research study would cure my illness."

— "I look forward to participating in this study with hope and enthusiasm."

Testing tool

O'Rourke says the tool was tested on 464 people, all older than 50, who were recruited online. Once the survey was developed further, it was administered to 37 people who had previously participated in a clinical trial.

He says both groups demonstrated similar degrees of misconception, despite the information given to them in the introductory paragraph.

"Ironically, all the information was there, to answer these questions 'correctly,'" O'Rourke says. "But it really didn't seem to make much difference."

And he noted that in a real clinical trial, this information is typically buried in a much longer, more complex informed consent document.

O'Rourke says he would like to see this screening tool widely used among researchers trying to learn more about therapeutic misconception. He says they purposely included the tool within the study, which was published recently online in the journal Aging and Mental Health, so that it could be easily accessed and disseminated more widely.

"Ideally, this will help us do better research around that (topic)," he says. "And yes, it could also be used as a secondary screening tool to ascertain to what degree people fully understand what they're enrolling in," particularly in pharmaceutical trials where there is risk of significant adverse effects.


Chou PH, O'Rourke N. Development and initial validation of the Therapeutic Misunderstanding Scale for use with clinical trials research participants. Aging Ment Health 2011 Sep 9 Epub.