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Understanding randomization of clinical trials crucial to success

December 21, 2016
Texas Tech University
A research team analyzed linguistic approaches to help cancer patients better comprehend the concept of randomization, being assigned by chance to treatment or control groups, in clinical trials.

Texas Tech researcher Melanie Sarge, was part of a team that analyzed linguistic approaches to help cancer patients better comprehend the concept of randomization, being assigned by chance to treatment or control groups, in clinical trials.

A doctor's office can be one of the most nerve-wracking places for some people. Being sick, going through a battery of tests or the anxious moments in anticipation of a diagnosis can bring a flood of thoughts and emotions.

It is a time when receiving, understanding and processing medical information is critical but can also hit roadblocks, not the least of which is patients' level of medical literacy. For some, hearing and understanding medical information can be like trying to understand Charlie Brown's teacher.

Ensuring comprehension becomes even more critical for patients considering participating in a randomized clinical trial. Not only is this an extremely difficult time to be making decisions but there is also a lot of information to digest before patients can truly make an informed decision, including understanding that they will be randomly assigned to a treatment.

Melanie Sarge, an assistant professor of advertising in the College of Media & Communication at Texas Tech University, was part of a research group led by Janice Krieger, an associate professor in the advertising department and director of the STEM Transitional Communication Center (STCC) at the University of Florida. The group studied how the health literacy of cancer patients influenced the effectiveness of various linguistic strategies in aiding understanding of the randomization of treatment in clinical trials.

"Dr. Krieger conducts research on clinical trials in an effort to make the clinical trial experience more understandable and possibly help individuals feel more comfortable about participating," Sarge said. "Overall the rate for clinical trial participation is about 3-5 percent for Americans. At the same time, clinical trials are imperative for this generation in advancing knowledge and medical treatment as well as patient care."

Sarge, who previously worked with Krieger at Ohio State University, was invited to participate on the project after moving to Texas Tech to contribute her expertise in data analysis and interpretation. Together with STCC research assistant Jordan Neil, Sarge analyzed which commonly used linguistic strategies for explaining randomization produced the highest levels of comprehension for people with both low and high levels of health literacy.

"There have been different linguistic strategies already identified as ways in which physicians explain the concept of randomization to their patients," Sarge said. "Metaphors appear to be one method that can enhance comprehension. A metaphor takes a concept that is unfamiliar and pairs it with a concept that is familiar to the patient. Creating this association enhances comprehension."

Gambling vs. benign

Through their research, the team found that certain metaphors were successful for patients possessing different levels of health literacy. Not all metaphors worked with all patients and for some, the metaphors were no better than using plain language to describe the situation.

One metaphor the team examined was termed the "gambling" metaphor. Simply put, it equates patient's chances of being placed in treatment groups to a coin flip, i.e. a 50-50 chance of being in one group or another. The other metaphor examined was termed the "benign" metaphor, sometimes referred to as the "baby" metaphor. This involves equating the patient's chances of being placed in treatment groups to guessing the sex of an unborn child, with an equal chance of having a boy or a girl.

"The gambling metaphor is a common strategy used by physicians to increase patient understanding of randomization," Sarge said. "However, we found the benign metaphor to be more effective among cancer patients with low health literacy because it provides a comparison that is familiar to them but does not imply a win-loss scenario."

Sarge and her fellow researchers discovered that the gambling metaphor worked best for those who reported high levels of health literacy, while the benign metaphor worked best for those with the lowest levels of health literacy. For those who were in the middle between high and low health literacy, both metaphors and plain language had about the same effect.

Debunking myths

In this study, the researchers also identified some of the affective factors that influence participation in clinical trials. There are many additional barriers that exist to clinical trial participation besides a lack of understanding. For instance, many worry that not being selected to a certain group would diminish the level of care received, despite assuring patients that no matter what treatment group they are randomly assigned to they would still receive, at a minimum, the acceptable standard of care for cancer patients.

"Randomization is important for several reasons," Sarge said. "Mostly it's the ability to make a comparison where otherwise you wouldn't be able to make conclusions about the effectiveness of one treatment over another. It's a good thing, but it's hard to understand, 'Why is my doctor not telling me what group I'm going to be in?'"

There's also the issue of certain patients having the feeling that, upon understanding the randomization aspect, they won't be getting a treatment they feel is tailored specifically to them, even though it could be the best treatment available. That increases anxiety about participation and anticipated success of the treatment. However, informed consent for a clinical trial is vital, both for medical and ethical reasons.

Indeed, Sarge and the researchers found a negative correlation between the understanding of randomization and the willingness to participate in clinical trials. "When patients have greater comprehension of the randomization process and realize it is not a tailored treatment, it is less personally relevant," Sarge said. "That increases anxiety and, in turn, we found, decreases the intention to participate."

Then there are other barriers that have to be overcome related to patient anxiety -- concerns about a reduction in quality of life, potential side effects from treatment, the feeling of this treatment being the last life-saving chance. Those all are concerns that have to be dealt with no matter the level of health literacy, and where metaphors play a key role. Sarge is involved with research examining messaging for breast cancer trials in order to decrease some of these concerns and increase the willingness to participate through cancer advocates sharing their own stories of participation.

"This type of communication research is extremely important for finding the language that will make physicians feel more comfortable talking to their patients about clinical trials as an option," Sarge said. "Equipping them with the message strategies they need to be able to increase understanding and willingness to participate is vital. However, while we're giving doctors recommendations on how to increase comprehension among certain groups, they need to keep in mind they might be lowering personal relevance and giving them more anxiety."

"It is important for the doctor to be there or some health practitioner to be there to help with the additional psychosocial barriers that exist."

Story Source:

Materials provided by Texas Tech University. Original written by George Watson. Note: Content may be edited for style and length.

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Texas Tech University. "Understanding randomization of clinical trials crucial to success." ScienceDaily. ScienceDaily, 21 December 2016. <>.
Texas Tech University. (2016, December 21). Understanding randomization of clinical trials crucial to success. ScienceDaily. Retrieved February 26, 2024 from
Texas Tech University. "Understanding randomization of clinical trials crucial to success." ScienceDaily. (accessed February 26, 2024).

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