Paying people to participate in clinical trials remains controversial. But to date, most reservations are based on hypothetical scenarios or expert opinion with few real-world data to support them.
Research released this week could change that.
Investigators offered nearly 1,300 participants in two clinical trials either no payment or incentives up to $500 to partake in a smoking cessation study or an analysis of a behavioral intervention to increase ambulation in hospitalized patients.
More cash was associated with greater agreement to participate in the smoking cessation study but not the ambulation trial.
But the bigger news may be that offering payment did not appear to get people to accept more risks or skew participation to lower-income individuals, as some ethicists have warned.
“With the publication of our study, investigators finally have data that they can cite to put to rest any lingering concerns about offering moderate incentives in low-risk trials,” lead author Scott D. Halpern, MD, PhD, the John M. Eisenberg Professor of Medicine, Epidemiology, and Medical Ethics & Health Policy at the University of Pennsylvania, Philadelphia, told this news organization.
This initial real-world data centers on low-risk interventions and more research is needed to analyze the ethics and effectiveness of paying people to join clinical trials with more inherent risk, the researchers note.
The study was published online Sept. 20 in JAMA Internal Medicine.
A good first step?
“Payments to research participants are notoriously controversial. Many people oppose payments altogether or insist on minimal payments out of concern that people might be unduly influenced to participate,” Ana S. Iltis, PhD, told this news organization when asked for comment. “Others worry that incentives will disproportionately motivate the less well-off to participate.”
“This is an important study that begins to assess whether these concerns are justified in a real-world context,” added Dr. Iltis, director of the Center for Bioethics, Health and Society and professor of philosophy at Wake Forest University in Winston-Salem, N.C.
In an accompanying invited commentary, Sang Ngo, Anthony S. Kim, MD, and Winston Chiong, MD, PhD, write: “This work is welcome, as it presents experimental data to a bioethical debate that so far has been largely driven by conjecture and competing suppositions.”
The commentary authors, however, question the conclusiveness of the findings. “Interpreting the authors’ findings is complex and illustrates some of the challenges inherent to applying empirical data to ethical problems,” they write.
When asked his advice for researchers considering financial incentives, Dr. Halpern said: “All researchers would happily include incentives in their trial budgets if not for concerns that the sponsor or institutional review board might not approve of them.”
“By far the biggest threat to a trial’s success is the inability to enroll enough participants,” he added.
Dr. Iltis agreed, framing the need to boost enrollment in ethical terms. “There is another important ethical issue that often gets ignored, and that is the issue of studies that fail to enroll enough participants and are never completed or are underpowered,” she said.
“These studies end up exposing people to research risks and burdens without a compensating social benefit.”
“If incentives help to increase enrollment and do not necessarily result in undue influence or unfair participant selection, then there might be ethical reasons to offer incentives,” Dr. Iltis added.
Building on previous work assessing financial incentives in hypothetical clinical trials, Dr. Halpern and colleagues studied 654 participants with major depressive disorder in a smoking cessation trial. They also studied another 642 participants in a study that compared a gamification strategy to usual care for encouraging hospitalized patients to get out of bed and walk.
Dr. Halpern and colleagues randomly assigned people in the smoking cessation study to receive no financial compensation, $200, or $500. In the ambulation trial, participants were randomly allocated to receive no compensation, $100, or $300.