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Clinical trial subjects link pay with risk levels; institutions performing trials do not, study says

This article first appeared in the St. Louis Beacon, Jan. 13, 2010 - Do you get paid more to participate in a risky medical study?

In a culture that rewards risk-taking with higher pay, this seems a logical assumption. Research institutions, however, generally reimburse only for the time and expenses required to participate in a clinical trial. People don't realize this. Participants assume higher paying clinical trials are higher risk, according to a new study from the Olin Business School at Washington University.

These differing assumptions about payment amounts could mislead potential subjects about the level of risk in a given clinical trial, according to the study authors. The findings contribute to the debate about appropriate research incentives and informed consent.

Informed consent

Human subjects have long been a part of medical and scientific research. But not until the world learned of the "experiments" forced on prisoners at Nazi concentration camps during World War II was informed consent standardized. The "Nuremberg Code," the first well-known document to outline the ethical use of human subjects in experiments, specified that consent must be voluntary, without coercion. Subjects must understand the nature of the study and the risks they will assume.

Today, medical schools and other institutions that use human subjects must have independent institutional review boards -- diverse panels that can include medical doctors, ethicists, scientists and community members -- dedicated to reviewing proposals for research with human subjects and granting or denying permission to conduct them.

While the definition of informed consent is easy to state, achieving it remains difficult. Appropriate pay for participation is one major area of debate.

Preventing 'undue inducement'

Guidelines recommend paying participants for their time and the expense of being in the trial, such as travel costs. The institution does not necessarily consider it compensation for risks the person may be taking in an experiment. The main concern is that high payments may "induce" subjects to participate when they would not otherwise. According to the review board's Guidebook, "undue inducements may be troublesome because offers that are too attractive may blind prospective subjects to the risks or impair their ability to exercise proper judgment."

But Cynthia Cryder, assistant professor of marketing at Washington University and the lead author on the paper "Informative inducement: Study payment as a signal of risk" in the journal Social Science and Medicine, sees a more complex picture.

"In the past, people have seen the not-surprising result that when you increase the compensation offered, more people participate. But what we see in this paper is that they're not just jumping on board blinded by the money offer. They consider studies that offer higher payment to be riskier and they consider information about the study more carefully," she said.

Adds Alex John London, associate professor of philosophy, director of the Center for the Advancement of Applied Ethics and Political Philosophy at Carnegie Mellon University, and a co-author of this study: "Our study challenges the view that larger incentives undermine the integrity of a person's decision-making process."

Pay and risk perception

When presented with identical procedures, people rated the procedure to be riskier when the compensation offered was higher -- $1,000 versus $25.

The study also looked at two different types of procedures. One was familiar, in this case a blood draw, and one was unfamiliar, in this case transcranial magnetic stimulation (a procedure in which a magnet that is placed on the scalp interferes with brain activity).

As the amount of money offered increased, more people expressed willingness to participate in both the familiar and unfamiliar procedures. But more money also corresponded with more time spent viewing information about the study, even for the familiar blood draw. When presented with the possibility of more money, people looked at more pages of information for longer periods of time and were more likely to view the contraindications -- conditions or symptoms that would increase individual risk from the procedure.

When people were told outright, "this amount of money was selected as being appropriate for the level of risk that the study poses to participants," the link between higher pay and higher perceived risk was even greater.

"Usually our doctors have our best interests in mind," said Cryder. "We go to them for services and we pay them to help us feel better or be healthier. But in a research study, they're not necessarily there for our welfare," she said. Payment may help to counter this therapeutic misconception, she explained. "The clinician is paying the participant and that helps to shoot up a red flag that "we're not necessarily here for me." she explained. This study, she said, demonstrates that the magnitude of the payment, beyond its simple presence or absence, could be informative as well.

"We can't just assume that participants think of payment as an incentive to be traded off for their time and effort," Cryder said. "They are making automatic assumptions about the activity they're being asked to do from the incentive that's offered to them."

Improving informed consent

Cryder explained two possible implications for review boards. "Potentially, (these boards) should be less worried about studies that pay a large amount of money," she said. "High payments actually seem to make people consider the study information more carefully."

Second, Cryder suggests that review boards should be more worried about studies that are risky but that offer little money. "Participants could infer that there's not too much to worry about with a study that pays only $10 or $25."

In such hypothetical instances, London says it might make sense to increase the level of compensation for risky, but otherwise low-paying studies and explicitly tell participants that the pay is related to the risks posed by the study. He is quick to point out that he does not know whether incentives can be used in this way.

"There isn't any other literature about whether payments can be used to enhance the informed consent process," he said. The discussion focuses almost entirely on the potential for payments to detract from it.

"One of the things our study shows is we've got to think more carefully about whether there are ways we can use incentives to improve the informed consent process of a clinical trial," he said.

Julia Evangelou Strait is a freelance science writer based in St. Louis. She is a 2009 Missouri Health Journalism Fellow.

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