A recent groundbreaking randomized controlled trial conducted by researchers at the University of Southern California sheds new light on the role of modest financial incentives in enhancing enrollment among low-income older adults into Alzheimer’s disease patient registries. This pivotal study addresses a critical challenge in Alzheimer’s clinical research: the underrepresentation of marginalized populations in trials designed to combat one of the most debilitating neurodegenerative diseases worldwide. By strategically deploying small gift card incentives, the researchers were able to significantly boost engagement, a finding that could reshape recruitment frameworks in clinical neuroscience.
The persistent underrepresentation of socioeconomically disadvantaged groups in Alzheimer’s research has long hindered the generalizability and equity of clinical trial outcomes. Low-income individuals, particularly those reliant on Medicaid, often face systemic barriers that discourage their participation. These can include limited access to information, mistrust of medical institutions, and logistical difficulties. The USC study notably interrogates the contested ethical terrain around financial inducements in research recruitment. While such incentives have sparked debate over potential coercion or undue influence, the absence of consensus regarding their size and practical impact has left many recruiters cautious.
To tackle this recruitment challenge, the investigators designed a large-scale experiment targeting adults aged 50 and older, all receiving care through an integrated county health system primarily serving Medicaid enrollees. Nearly 50,000 individuals without a dementia diagnosis were invited via email or text message to join the Alzheimer Prevention Trials (APT) Webstudy, an influential platform aimed at accelerating clinical trials by earmarking higher-risk individuals for long-term monitoring. Participants were randomized into three distinct groups to compare the effectiveness of recruitment messaging and incentives.
The first group, termed the active control, received a baseline recruitment message that simply invited them to register in the memory concerns registry. The second group was offered a small yet tangible incentive: a $25 Amazon gift card contingent upon their enrollment. The third group experienced a different approach—entry into a prize drawing for a substantially larger $2,500 Amazon gift card, with odds set at 1 in 100. This structure allowed the researchers to evaluate not only whether incentives worked but also which type was most effective in motivating participation across diverse demographic segments.
The results were striking. The small guaranteed gift card incentive yielded nearly a 40% increase in enrollment compared to the control group, demonstrating that even modest financial rewards can substantially augment recruitment efforts among low-income older adults. A nuanced analysis revealed that the incentive was particularly effective for white males and Medicaid enrollees, populations historically underrepresented in clinical research. Interestingly, the lottery-style prize drawing did not produce any significant recruitment benefit, suggesting that the certainty of reward plays a more critical role in influencing participant behavior than the allure of larger but uncertain payoffs.
These findings challenge prevailing assumptions in clinical trial recruitment strategies, especially concerning cost-effectiveness. While the gift card incentive increased enrollment rates, the study observed that the baseline messaging without financial inducements remained a considerably cheaper method with a reasonable recruitment yield in absolute terms. This insight has profound implications for how research institutions allocate limited funds, particularly when balancing recruitment goals against budgetary constraints.
The study authors argue that investing in targeted outreach efforts, educational programs, and structural supports for underrepresented communities might ultimately be a more sustainable and ethically sound approach than relying solely on financial incentives. Outreach initiatives that build trust and reduce systemic barriers could complement the recruitment process, thereby fostering genuine engagement and retention in registries and trials over the long term.
Conducted through the Alzheimer’s Trial Recruitment Innovation Lab (ATRIL)—a synergistic collaboration between the USC Schaeffer Center, the Alzheimer’s Therapeutic Research Institute (ATRI), and Howard University—this research embodies a multidimensional effort to revitalize diversity in Alzheimer’s clinical research. Funded principally by the American Heart Association, ATRIL exemplifies how cross-institutional partnerships can mobilize resources and expertise to tackle entrenched inequities in clinical trial participation.
The lead investigators, Mireille Jacobson and Doris Molina-Henry, bring complementary expertise from gerontology, neuropsychology, and neurology, enabling a comprehensive approach to trial design and participant engagement. Their work, published on August 22, 2025, in JAMA Health Forum, contributes not only empirical data on incentive efficacy but also a valuable ethical discussion on the delicate balance between compelling participation and respecting autonomy.
The research further situates itself within a broader landscape of ongoing debates regarding medical ethics in clinical trial recruitment. Financial incentives, though controversial, if structured responsibly, may act as facilitators of equity rather than coercion. However, the absence of a positive effect from larger, lottery-based rewards tempers enthusiasm for “carrot-and-stick” tactics that rely purely on economic enticement without mitigating other participation barriers.
On a methodological level, the study’s rigorous randomized controlled design provides robust evidence, minimizing biases that may have plagued prior observational or anecdotal investigations. Randomization ensured equitable distribution of sociodemographic factors, enabling confident attribution of observed recruitment differences to the incentive interventions themselves rather than confounding variables. This strengthens the case for practical application of such incentives in real-world trial recruitment.
Moreover, by focusing on a memory concerns registry rather than a direct clinical trial, the study recognized the foundational importance of early-stage engagement and tracking. Registries serve as critical reservoirs of eligible participants, streamlining recruitment pipelines for subsequent interventions and observational studies. Enhancing their diversity amplifies the translational impact of Alzheimer’s research, increasing the external validity of findings and facilitating development of treatments that are effective across population strata.
Despite its promising insights, the study also underscores that financial incentives constitute only one piece in a complex puzzle of clinical trial engagement. The interplay between socioeconomic status, race, gender, health literacy, and institutional trust necessitates multifaceted intervention strategies. Future efforts might integrate incentive programs with culturally tailored communication, community partnership models, and technological innovations to create an ecosystem conducive to inclusive research participation.
In summary, the USC-led investigation delivers compelling evidence that modest financial incentives can notably improve enrollment rates of low-income older adults in Alzheimer’s disease registries without ethical compromise or excessive cost. It simultaneously critiques the allure of large-prize lotteries, emphasizing the importance of predictable rewards and thoughtful resource allocation. Their findings pave the way for reimagining recruitment paradigms that, combined with community engagement and systemic reforms, hold promise for accelerating Alzheimer’s research while ensuring equity and representativeness.
Subject of Research: Recruitment strategies to increase diversity of older adults in Alzheimer’s disease patient registries through financial incentives.
Article Title: Financial Incentives to Increase Diversity of Older Participants in a Memory Concerns Registry
News Publication Date: 22-Aug-2025
Web References:
https://www.alzheimers.gov/clinical-trials/alzheimer-prevention-trials-apt-webstudy
https://schaeffer.usc.edu/people/mireille-jacobson-phd/
https://schaeffer.usc.edu/people/doris-molina-henry-phd/
https://schaeffer.usc.edu/clinical-trial-recruitment-lab/alzheimers-trial-recruitment-innovation-lab/
References: Jacobson M, Molina-Henry D, et al. Financial Incentives to Increase Diversity of Older Participants in a Memory Concerns Registry. JAMA Health Forum. 2025; DOI:10.1001/jamahealthforum.2025.2273.
Keywords: Alzheimer disease, Clinical trials, Medical ethics, Dementia, Medical economics, Geriatrics
