Health Law Daily Wrap Up, CLINICAL RESEARCH—OTHER AGENCY DOCUMENTS: ASPE report provides overview of prevalence of compensation in clinical research studies, (Aug 6, 2025)

By Sherri M. Schroeder, J.D.

The analysis shows that compensation is relatively common across clinical research, but it varies dramatically by intervention type, study phase, and health condition category.

Implementing a text mining approach using informed consent files available in ClinicalTrials.gov, HHS’s Assistant Secretary for Planning and Evaluation (ASPE), Office of Science and Data Policy, has issued a brief examining the use of participant compensation in U.S. clinical research studies. Of the 7,648 U.S.-based clinical research studies identified, this approach identified over 4,548 studies as offering participant compensation. The percentage of studies offering compensation varied between intervention types (10.2 percent – 84.2 percent), trial phases (34.8 percent – 63.3 percent), and health conditions being studied (22 percent – 90.6 percent). According to the study’s author, Allison Kolbe, these results highlight the need for additional research into the use of compensation in clinical research studies, particularly its effectiveness to improve patient recruitment and retention (ASPE Issue Brief, July 30, 2025).

According to the report, the financial impacts of participating in clinical research, such as out-of-pocked medical expenses, travel expenses, lost wages, and other factors, are thought to reduce study participation. However, a growing body of literature suggests that compensating research participants for their time may be one way to offset these costs and improve or incentivize recruitment and retention. Despite this, “there remains a fundamental gap in our understanding of how widely compensation is currently used in clinical research,” per Kolbe. As a first step in closing this gap, the issue brief presents an analysis of compensation use across 7,648 clinical research studied conducted in the U.S. broken down by trial phase, intervention type, and health condition. The issue brief “builds on existing literature by applying a single approach for identifying compensation to a wide range of clinical research studies, regardless of sponsoring institution, study phase, or therapeutic area.”

The text mining approach classified 4,548 studies—or 59.5 percent—as offering compensation. Within this group, compensation varied dramatically by intervention type, study phase, and health condition category, as follows:

• Intervention type: A much higher percentage of studies with a behavioral intervention (84 percent) offered compensation relative to those with device (58 percent) or drug (43.5 percent) interventions. Radiation studies were the least likely to offer compensation (10.1 percent).

• Study phase: Early phase 1 trials, which are exploratory trials conducted before traditional phase 1 trials to investigate how or whether a drug affects the body, were the most likely to offer compensation, while studies in phases 2 or 3 were slightly less likely to offer compensation.

• Health category: The percentage of studies offering compensation varied dramatically between health categories. Among the 10 most common health categories in the sample, the percentage of trials offering compensation ranged from over 80 percent for diabetes and neuropsychiatric studies to less than 25 percent of cancer/malignant neoplasm studies. Delving further into the data concerning neuropsychiatric conditions and malignant neoplasms showed that studies for diseases such as Parkinson’s and Alzheimer’s offered compensation less frequently than alcohol or drug use disorder studies. However, all the neuropsychiatric subcategories offered compensation more frequently than cancer trials.

Its author notes that the study did not explore the amount of compensation provided, “which may affect the degree to which it impacts recruitment and retention.” Variation in the cost of running the study may also influence the study sponsor’s likelihood of offering compensation. In addition, recent research has shown that the amount of compensation may influence participation gaps by factors such as socioeconomic status and race, which, according to Kolbe, demonstrates the importance of appropriately scaled incentives to engage underrepresented populations in research. Kolbe also notes that the study approach utilized was unable to generate quantitative estimates of compensation due to the “extremely variable” nature of the content in the informed consent files, meaning that “[f]uture work using more sophisticated language processing techniques may be able to build on the current approach to explore this question further.”

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