Sociodemographic characteristics of participants.

Background
Financial compensation is an important aspect of respect for people enrolled in clinical research, yet continues to raise ethical questions. Respondents’ characteristics, shaped by contextual and geographic factors, may influence perceptions of the ethical implications of financial compensation. This study explored the relationship between respondents’ characteristics and their ethical perspective on the role of financial compensation in prevention trials in Tanzania.
Materials and methods
A cross-sectional survey of 537 participants from two prevention studies within Tanzania was conducted. Participants were eligible if they participated in either the HIV Pre-Exposure Prophylaxis Vaccine Trial (PrEPVacc) trial or a non-inferiority trial of low-dose compared to standard high-dose calcium supplementation in pregnancy in Tanzania. A questionnaire was used to collect participants’ sociodemographic characteristics and motivating reasons for research participation. Data analysis was performed using descriptive statistics for all variables. The chi-square test was used to assess associations between categorical demographic characteristics and binary outcomes scores. Modified Poisson regression models were employed to examine predictors of positive or negative perspectives for each outcome. The P value of < 0.05 was used to ascertain the significant association between the variables.
Results
Most participants (82.5%) were young adults between the ages of 18–28 years, married or cohabiting (60.7%), and self-employed (55.9%). All participants in the cohort were female. Key motivations for research participation included medical follow-up (96.8%), quality information (94.4%), and disease control (92.2%). The majority also reported feeling a duty to participate (90.5%) with 50.1% indicating that they felt an obligation to the person who requested their participation. More than a third (36.9%) wanted to receive an incentive and reimbursement (38.7%) for out-of-pocket expenses. Financial compensation was a less common motivator among married or cohabiting participants compared to single individuals (APR = 0.54, 95% CI: 0.42–0.71, p < 0.001). Participants with primary education were also less likely to report financial compensation motivations compared to those with no formal education (APR = 0.57, 95% CI: 0.41–0.78, p < 0.001). Also, participants who had taken part in two or more trials had significantly higher non-financial participation motivations compared to those with only one research experience (p < 0.001).
Conclusion
Financial compensation matters to certain participant subgroups, but its role varies. While some value monetary benefits, others prioritize altruism and trust in research oversight. A balanced, transparent compensation framework is needed to address financial needs while maintaining ethical integrity.