Human guinea pigs wary of high-paying medical trials

Research institutions view payments to volunteers as compensation for time and expenses; not as compensation for potential risks related to participating in the experiments. A new study finds that volunteers have a very different view of clinical trial compensation. High-paying research studies raise a red flag for human guinea pigs and signal high levels of risk.

The findings from a study published in December by the journal Social Science and Medicine have implications for informed consent in human subjects research and the debate over research participation incentives.

Cynthia Cryder, assistant professor of Marketing at the Olin Business School, Washington University in St. Louis, is the lead author of the study, "Informative Inducement: Study Payment as a Signal of Risk"*. Her co-authors are Alex John London and George Loewenstein at Carnegie Mellon University and Kevin G. Volpp at the University of Pennsylvania School of Medicine and the Wharton School.

"At a big-picture level, what stands out from these results is that research participants do not just consider participation payments as an incentive to be traded off for their time." Cryder explains. "They actually infer information about the study itself from the participation payment."

Cryder and colleagues conducted three experiments to measure people's interest in participating in potentially risky research studies, their perception of the risk associated with those studies and how payment amounts affected their interest and perceptions.

Experiments for the study were conducted with an online nationwide sample or a sample from a northeastern U.S. city in 2007-2008.

The study finds that while high pay is a real incentive for people to participate in clinical trials, it also increases the "perceived risk" of the trial and the time potential volunteers spend researching and viewing information about risks related to the trial.

"Specifically in our experiments," Cryder explains, "they [participants] judge studies that offer high payments to be riskier than identical studies that offer low payments."

George Loewenstein, the Herbert A. Simon Professor of Economics and Psychology at Carnegie Mellon and co-author of the study, says these findings contradict some of the common guidelines used for establishing participation incentives:

"Most organizations that do research prohibit participation payments that substantially exceed compensation for time and expenses. The fear is that people will be overly tempted by high payments to take excessive risks. Our research challenges this common practice. It suggests that people assume that studies that don't pay much aren't risky."

The study concludes that there is a "mismatch" between current research guidelines for setting compensation levels and the assumptions participants make about the levels of pay and risk. Loewenstein explains:

"Contrary to the assumption that high payments are excessively tempting, our research suggests that they alert subjects to potential risk and make them more vigilant about protecting themselves. An added bonus of high payments is that it is ethically sensible for people to be adequately compensated when they do, in fact, incur risks."

The authors of the study believe their findings should contribute to the debate over research participation incentives and informed consent. The way potential human subjects interpret payment, risk and information about clinical trials as documented in the Cryder et al paper sheds new light on the role of the human subjects in research.