Healthy volunteers in US phase I clinical trials: Sociodemographic characteristics and participation over time

Abstract

Background Increasing the diversity of research participants is an important focus of clinical trials. However, little is known regarding who enrolls as healthy volunteers in Phase I clinical trials, which test the safety and tolerability of investigational new drugs. Despite the risk, healthy volunteers can derive no medical benefit from their participation, and they are financially compensated for enrolling. Objective This study’s purpose is to describe sociodemographic characteristics and clinical trial participation histories of healthy people who enroll in US Phase I trials. Methods The HealthyVOICES Project (HVP) is a longitudinal study of healthy individuals who have enrolled in Phase I trials. We describe self-reported sociodemographic information and Phase I trial history from HVP recruitment (May-December 2013) through the project’s end three years later (December 2016). Trial experiences are presented as medians and quartiles. Results The HVP included 178 participants. Nearly three-fourths of participants were male, and two-thirds were classified as racial and ethnic minorities. We found that some groups of participants were more likely to have completed a greater number of clinical trials over a longer timeframe than others. Those groups included participants who were male, Black, Hispanic, 30-39-years-old, unemployed, had received vocational training in a trade, or had annual household incomes of less than $25,000. Additionally, the greater the number of clinical trials participants had completed, the more likely they were to continue screening for new trials over the course of three years. Participants who pursued clinical trials as a full-time job participated in the greatest number of trials and were the most likely to continuing screening over time. Implications Participation as a healthy volunteer in US Phase I trials is driven by social inequalities. Disadvantaged groups tend to participate in a greater number of clinical trials and participate longer than more privileged groups.

Characterizing altruistic motivation in potential volunteers for SARS-CoV-2 challenge trials

“…Notably, our sample of intended volunteers is in some ways similar to “typical” healthy volunteer research participants in clinical trials in that they are predominantly male. But they are markedly different from what has been observed in previous studies of phase I study participants [ 24 , 62 ] in that the intended volunteers in our sample were less likely to belong to demographic or socioeconomic groups most vulnerable to exploitation, including ethnic minorities, low-income earners, or unemployed individuals. This suggests that existing concerns about healthy volunteers who participate in other types or research in different contexts, do not necessarily generalize to healthy volunteers who were willing to participate in a COVID-19 HCT early in the pandemic.…”

Why not? Motivations for entering a volunteer register for clinical trials during the COVID-19 pandemic

“…As for socio-demographic characteristics, our sample presented a higher percentage of individuals employed and with higher education in comparison with healthy volunteers from other countries such as the USA, China, Belgium and Singapore [ 5 , 8 , 25 ]. As lower socio-economic status has been proved to be linked to economic drivers and “serial participation”, high dropout rates, and over-representation of disadvantaged minorities [ 5 – 7 ] which pose ethical and safety concerns, some authors advocated for implementing and fostering the use of national registers to overcome these issues [ 6 , 28 ] as they guarantee a higher control over participation in clinical trials and a reduction in time and costs related to the recruitment process [ 29 – 31 ].…”

“…When compared to previous data on motivations of healthy volunteers to participate in clinical trials for Ebola and adjuvant influenza vaccines [ 10 ], in our sample, self-reported altruistic motivations played a stronger role while self-interested motivations were extremely less frequent. Although we need to caution about the particular effect that the COVID-19 pandemic may have had on study participants’ motivations, this result fosters discussion about possible differences in motivational profiles between volunteers enrolling in public vs private registers and whether and to what extend these differences play a role in reducing serial participation or early dropout rates which are often reported among US healthy volunteers [ 5 , 24 , 25 ]. Further data are needed.…”

“…Healthy volunteers do not derive any personal therapeutic benefits as they are not directly affected by the disease under study. In countries and contexts where they are licensed, monetary incentives to enrol are strong and debated motivating factors [4] often linked to the practice of serial participation and the overrepresentation of disadvantaged groups [5][6][7]. Other often reported motivating factors are more linked to feelings of personal gratification, and altruistic or moral rewards [8].…”

The Importance of Participant Tracking When Conducting Clinical Pharmacology Drug Trials

“…These “occupational” or “professional” research individuals will seek out and enroll in numerous types of trials throughout a calendar year, at times in quick succession, and may even attempt to participate in more than 1 trial simultaneously 1 . Current literature has indicated that approximately one‐third of those participating in clinical pharmacology studies fall into this “occupational” category 1 . Unfortunately, some participants take an indifferent attitude toward the risks inherent in participating in multiple trials over short periods of time or enrolling in trials sequentially, even though they are well informed and repeatedly warned of the risks by the researchers conducting these trials.…”