Should We Be Paying Clinical Research Participants? A Global Perspective

By Eduardo F. Motti, MD, founder, Trials & Training

Payment to clinical research participants has taken center stage in recent years, with a plethora of articles, discussions, and even an Office for Human Research Protections workshop in 2022, “Beyond Altruism — Exploring Payment For Research Participation.”¹ The focus continues in 2025, likely because of the difficulty recruiting participants, the emergence of payment companies, and the intricacies of ethical issues related to paid participation.

While clinical trials in the United States account for only 20.58% of the global total, according to the WHO², most publications discussing the problem and proposing solutions for participant payment are U.S.-centric. Clinical studies are done globally, where regulatory and cultural aspects sometimes diverge from what is common in the U.S., and this has been underappreciated in most publications. Let’s explore.

The Ethics Of Patient Payment And Who Decides What’s Right

Payment to participants may influence the ethical principle of autonomy, since participants may be compelled to enter a clinical study because they will get paid and might even conceal information that might have prohibited them from enrolling. Data from American patients in two separate trials showed  this did not happen when payments were between $100 and $500.³ That brings us to the following questions: What are we paying for? What is reasonable payment, for whom, and where?

Across the world, participants must be reimbursed for out-of-pocket expenses related to the trial, including transportation to the site(s) and meals. That amount may vary depending on the trial needs, especially if air travel and overnight stays are necessary. But what about payment for childcare (even animal care) and lost work hours related to site visits? And, are appreciation gifts OK?

There is a continuum in the ethical evaluation from expense reimbursement, lost time, incentives, and payment for participation. There are wide variations on trial requirements, regulatory specificities, and cultural customs to be observed; it is almost impossible to establish globally accepted rules on values and practices. Payment should be considered on a case-by-case, trial-by-trial, and country-by-country basis. Sites and investigators are most qualified to determine payment. Sponsors and ethics committees need to take their word into consideration when reviewing and approving the budget for payments.

Lean On Site Staff For Payment Expertise

Duenas et al⁴ stated that the ethics of payment to participants is mainly related to respect and summarized it in five considerations: “(1) practice cultural humility, (2) be mindful of socioeconomic factors, (3) be flexible, (4) be transparent, and (5) maintain open communication.” I cannot emphasize enough the importance of relying on the people who are cognizant of the participants and their socio-cultural status — the investigator and site staff, they are in the best position to evaluate what to pay for, when, and how much.

Sponsors generally do not want to micromanage participant payments and many investigators consider managing payments demanding on their sites. That has created an opportunity for service companies to take responsibility for the task, in exchange for a share of the study budget. I believe it is in the best interest of investigators to manage payments themselves; it can straighten relationships with patients and reinforce trust with open, two-way communication. In the busiest sites, investing in a resource to manage payment administration may be best. Proximity and efficient communication are crucial for better recruitment and retention.

Remember: The American Perspective Isn’t The Only Perspective

Articles published by American researchers tend to consider it unethical not to pay volunteers for their participation in a study. Esiason, Pontus, and Gelinas stated: “Others who give their time and undertake burdens and risks for the public good, such as firefighters or other first responders, are compensated appropriately. Research participants should not be treated any differently.”⁵ I argue that they should. Participation in research is not a profession. Patients enter a clinical study mainly with hope — hope to get better, hope to get better assistance, hope to help others — and trust — trust in the people and trust in the process. Transforming participation in clinical trials into a commercial endeavor is a distortion, even when wrapped up with nice words and intentions.

Obvious exceptions are studies performed in healthy volunteers or when no benefit is expected to participants, like Phase 1 and bioequivalence studies. Payment for participation is the norm in those cases, but even so, the amounts paid should be individualized and carefully evaluated by the ethics committees.

One issue that has not been discussed in most publications is the burden of the baseline disease to patients (and their families). Entering a clinical trial may increase that burden: repeated visits to the sites, tests that would not be routinely performed, and uncertainty about the study may be barriers to participation. At the same time, entering the trial may reduce the disease burden by providing free medication, tests, and 24/7 assistance that otherwise would not be available. This could be less apparent in countries with well-established healthcare systems or in those with patients of high socioeconomic status and means. But it does become increasingly important when we aim for more patient diversity and underserved populations, whether in the U.S. or abroad. Because when studies are done in situations where medical assistance is deficient, clinical trials and the care they bring may be the greatest motivation for patient participation.

Brazil, As An Example

Let me provide a counterpoint to the situation in the U.S. with Brazil. Traditionally, payment for participation in research is not allowed, just reimbursement for out-of-pocket expenses. That has recently been incorporated in the new clinical research law approved in 2024.⁶ Despite that, recruitment is usually a strong point of Brazilian sites. The same law establishes that the sponsor must provide the means for all protocol-related procedures and treatments and provide care for study-related adverse events. That is divergent with the standard-of-care practices in the U.S. that require patients or their health insurers to provide standard (though not the investigational) drugs used in the study. The additional cost for sponsors, which must provide all drugs in the study, results in greater patient safety and increased quality for the study, since sponsors gain full control of the quality and use of supplies. It is also a very important boost for recruitment.

Final Thoughts On Patient Payment

Patient payment is probably one of the least significant lines of the study budget, but the variables behind it are amazingly and increasingly complex. In many cases, we are complicating something that should be simple and transparent by following these suggestions:

1. Understanding and abiding by the cultural and regulatory norms of each country.
2. Listening to the experience of principal investigators.
3. Ensuring that whatever payment is decided, it is clearly described in the consent form and readily available when patients come to the site. (Tip: Cash is king.)

References:

1. www.hhs.gov/ohrp/education-and-outreach/exploratory-workshop/2022-workshop/index.html
2. https://www.who.int/observatories/global-observatory-on-health-research-and-development/monitoring/number-of-clinical-trials-by-year-country-who-region-and-income-group
3. Halpern, SD et al. Effectiveness and Ethics of Incentives for Research Participation 2 Randomized Clinical Trials. JAMA Intern Med. 2021;181(11):1479-1488. doi:10.1001/jamainternmed.2021.5450.
4. Duenas DM, Weiss EM, Wilfond BS, and Kraft SA. Ethical considerations for respectful research participant payment processes. Journal of Clinical and Translational Science 8: e204, 1–7. doi: 10.1017/cts.2024.650
5. Esiason G, Pontius A, Gelinas L. Show them the money: a multi-stakeholder perspective on reforming clinical trial participant compensation. Nat Rev Drug Discov. 2024 Dec;23(12):881-882. doi: 10.1038/d41573-024-00107-2. PMID: 39026039.
6. Law 14874/2024 – published on May 28^th, 2024 in the Brazilian Official Gazette.

About The Author

Eduardo Motti, MD graduated in with a degree in medicine from São Paulo University Medical School, Brazil in 1978, and later specialized in infectious diseases. After working as a clinician until 1990, he moved to clinical research in the pharmaceutical industry, having worked at Merck Sharp & Dohme, Eurotrials, Bayer, and Pfizer. In 2012, he founded Trials & Training, a consulting company, and graduated as an executive coach from Royal Roads University in Canada in 2013. In 2020, he was awarded Global Fellow in Medicines Development by the IFAPP Academy. Dr. Motti has worked directly in over 500 clinical research projects, led clinical operations for Pfizer in Latin America, and provided training, coaching and mentoring to hundreds of health professionals.