Understanding Motivation to Participate in Clinical Trials: Insights to Diversify Clinical Research Using Health Information National Trends Survey

Motivation plays a central role in driving individuals to participate in clinical trials, and understanding its multifaceted nature is essential for improving trial diversity. This study aimed to (1) identify the different dimensions of motivation for clinical trial participation, (2) examine the sociodemographic and health predictors of motivation, and (3) test whether the predictors differ by gender, race, and ethnicity. Data were drawn from the 2020 Health Information National Trends Survey (HINTS 5, Cycle 4; n = 3865). Eight survey items assessing motivation were analyzed using factor analysis, leading to the creation of three latent domains (general, material, and care-related motivation) via Structural Equation Modeling (SEM), which served as study outcomes. SEM was applied to estimate associations between predictors and each motivation domain, both in the pooled sample and across gender, race, and ethnic subgroups. In the pooled sample, higher educational attainment (beta = 0.118, p < 0.001) was positively associated, and Black (beta = −0.074, p < 0.05) and other races (beta = −0.122, p < 0.001) were negatively associated with the motivation general outcome. Age (beta = −0.365, p < 0.001) and income (beta = −0.081, p < 0.05) were negatively associated with the motivation material domain. Educational attainment (beta = 0.135, p < 0.001), income (beta = 0.092, p < 0.05), depressive and anxiety symptoms (beta = 0.090, p < 0.01), and cardiometabolic conditions (beta = 0.089, p < 0.01) showed positive associations with the motivation care outcome, while age was negatively associated (beta = −0.089, p < 0.05). Multi-group SEM showed significant gender-, race-, and ethnicity-specific differences. Motivational patterns differed by gender, race, and ethnicity, emphasizing that understanding these variations can strengthen recruitment, retention, and inclusivity in clinical trials.