More than the money: A review of the literature examining healthy volunteer motivations

Background and objective: Few existing data report the motivations of healthy volunteers in clinical research trials. Some worry that volunteers consider only financial motivations. This study summarized and analyzed existing empirical research on self-reported motivations of healthy volunteers participating in studies not intended to offer benefit from participation. Study selection: A systematic PubMed search was conducted. Inclusion criteria captured English-language empirical studies on the self-reported motivations, reasons, or factors influencing the decision of healthy volunteers to enroll in clinical research. Thirteen studies involving more than 2000 healthy volunteers met the criteria and were included in this review. Data extraction: Independent review by the authors and extraction of information about the sample, methodology and objectives of the motivations study, description of the clinical trial and whether participation was actual or hypothetical, reported primary and secondary motivations of the healthy volunteers, risk evaluation, and reported differences in motivations related to sociodemographic variables. Results: This review showed that although financial reward is the primary motivation for healthy volunteers to participate in clinical trials, financial motivations are one among many other reported motivations, including contributing to science or the health of others, accessing ancillary healthcare benefits, scientific interest or interest in the goals of the study, as well as meeting people and curiosity. Volunteers consider risk when making a decision about participation. Conclusions: Although financial incentives are important in recruiting healthy volunteers, their motivations are not limited to financial motivations. Further research is needed to examine motivations in different contexts and countries, the decision making of healthy volunteers, and the dynamics of repeat participation.