Do research subjects retain informed consent details?
Small subset has trouble remembering information
A small but notable percentage of veterans in a long-term drug study were unable to retain some of the simplest information about it — including the purpose of the study, the name of the drug and its main side effect — for the entire course of the trial.
The retention study's author notes that while most of the participants were able to remember this information, the group that didn't was disproportionately older, less educated and non-white.
Joan M. Griffin, PhD, a researcher at the Minneapolis VA Medical Center, in Minnesota, says she was surprised by the variation in retention based on age, race and education.
"It's really unclear what's going on in this small minority that doesn't understand these things," she says. "But if it is the case that these groups don't understand the language of clinical trials and are just in [the trial] and aren't informed, there are obviously gaps that we need to address from the get-go."
She says the findings suggest that researchers must work harder to simplify informed consent for all participants, and should reiterate key information as needed in long-term clinical trials.
"With these basic things, if you can really inform the patient over and over again, I think it would be helpful," Griffin says.
Survey part of cholesterol study
The retention study was published in the October 2006 issue of Contemporary Clinical Trials.
The survey was added to the end of a clinical trial conducted at VA hospitals during the 1990s among male veterans with heart disease and low levels of high density lipoprotein (HDL) cholesterol. The VA HDL Intervention Trial, a double-blinded, randomized, placebo-controlled study, looked at whether raising HDL cholesterol using medication prevented heart attacks and death from heart disease.
Informed consent for the trial included explanation by a study coordinator about several key points: the purpose of the trial, randomization, the name of the medication (gemfibrozil), possible risks and benefits, a patient's right to withdraw from the study and the drug's potential side effects, including the main side effect, gallstones.
Copies of the informed consent form also were provided to patients. If the coordinator determined that the patient couldn't understand the consent procedure, he was considered ineligible.
At the end of the five-year trial, during the patient's final follow-up visit, he was asked three questions about the study: The purpose, the name of the drug and its main side effect.
Out of 1,789 participants who answered at least one of the questions (missing answers were counted as incorrect):
- 35.3 percent could not identify the purpose of the study;
- 20.4 percent did not know the name of the medication;
- 68.9 percent couldn't state the main side effect of the medication.
Of the total group, non-white participants were more likely to get two of the three questions wrong. More than half (54.3 percent) of non-white participants could not identify the purpose of the study, while 27.2 percent couldn't name the medication. But more non-white participants were able to identify the main side effect (64.2 percent incorrect, compared to 69.3 percent of whites).
For each question, participants who were older than 70 were more likely than the group as a whole to answer incorrectly, as were those with less than a high school education.
It's possible, Griffin says, because of the age of the subjects, that cognitive decline may have led to their forgetting the facts of the trial.
"This brings a note of caution to people who are conducting studies," she says. "If they are working with populations of older adults, they really do need to take additional time in the consenting process, and then probably reiterate that information over the course of the study."
Griffin emphasizes that the majority of the participants surveyed knew the most basic details - the study's purpose and the name of the drug.
"The point we're trying to make in the paper is that even though the majority of people did know that basic rudimentary information, the proportion that didn't are those that are underrepresented in clinical trials," she says. "That's where we really need to work because those may also be the people who are most likely to quit a clinical trial."
And she points out that the details asked for in the study were the most fundamental facts about the clinical trial, leading to concerns that more complicated issues have even lower retention.
"We haven't even tackled some of the things like issues around randomization, which I think are very difficult for people to understand," Griffin says. "There's risk assessment — it's been shown in the literature that very few people understand risk."
One limitation of Griffin's study is that veterans were only asked the study questions at the end of the clinical trial. There was no data to show how many knew the information at the outset of the trial. But because the information asked of the participants was so basic, Griffin says she finds it hard to imagine how they could have been signed up for the study without knowing it.
Simplify and repeat details
Of the three questions asked, the question about side effects drew the largest number of incorrect responses. Griffin says the group that answered it correctly simply may have been more interested in that information or may have suffered the side effect themselves, so they remembered it better.
By far, the best remembered fact about the study was the name of the drug, and Griffin says that may point to repetition as a potent tool for helping patients remember details of a clinical trial.
"Perhaps one of the reasons that people knew the name of the study medication was that it was reiterated so frequently when they came in for their medication," she says. "We can learn a lot by repeating that information."
But Griffin says she hopes the results of this study don't cause IRBs to simply demand that researchers repeat information to subjects over and over, or to target groups such as minorities for special treatment.
"I worry about bias, the kind of stereotyping that can go on," she says. "You end up having a study and you assume that this population is not going to understand it more because of their age or the color of their skin."
She says a better response to these concerns would be to simplify the process of informed consent for everyone, with extra repetition of information in more complex studies. Co-ordinators should allow participants to take the time they need to truly understand the information, rather than rushing through a rote explanation.
"Target the information to the lowest reading level possible, because everybody can benefit that way," she says. "If it's a more complex trial, you could have more reminders throughout the trial."
Griffin noted another common teaching tool for health literacy, the "teach back" method, in which the coordinator goes over the material, then asks the participant to repeat the information back in his own words.
In addition to improving understanding of informed consent and retention of study details, these strategies also could help fight attrition rates, which could include groups of people who really didn't understand the study.
"It may be that those people are that same population that may be most likely to quit, and there may be another part of that population that didn't even participate in the study, because consent forms can be scary," Griffin says. "And if one of the things that we're trying to do is represent the underrepresented, then we need to make consent forms simpler from the very beginning."
Source
Griffin JM, et al. Long term clinical trials: How much information do participants retain from the informed consent process? Contemporary Clinical Trials. 2006;27:441-448..
A small but notable percentage of veterans in a long-term drug study were unable to retain some of the simplest information about it including the purpose of the study, the name of the drug and its main side effect for the entire course of the trial.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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