Ezekiel J. Emanuel


Mar 11 '19

Motivations, Enrollment Decisions, and Socio-Demographic Characteristics of Healthy Volunteers in Phase 1 Research

Grady C, Bedarida G, Sinaii N, Gregorio MA, Emanuel EJ. 

Clinical Trials, October 2017.

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Phase 1 trials with healthy volunteers are an integral step in drug development. Commentators worry about the possible exploitation of healthy volunteers because they are assumed to be disadvantaged, marginalized, and inappropriately influenced by the offer of money for research for which they do not appreciate the inherent risks. Yet there are limited data to support or refute these concerns. This study aims to describe the socio-demographic characteristics, motivations, and enrollment decision-making of a large cohort of healthy volunteers.


We used a cross-sectional anonymous survey of 1194 healthy volunteers considering enrollment in phase 1 studies at Pfizer Clinical Research Units in New Haven, CT; Brussels, Belgium; and Singapore. Descriptive statistics describe motivations and socio-demographic characteristics. Comparisons between groups were examined.


The majority rated consideration of risks as more important to their enrollment decision than the amount of money, despite reporting that their primary motivation was financial. Risk, time, money, the competence and friendliness of research staff, and contributing to medical research were important factors influencing enrollment decisions for most participants. The majority of healthy volunteers in this cohort were male, single, reported higher than high school education, and 70% had previous research experience. Many reported low annual incomes (50% below USD$25,000) and high rates of unemployment (33% overall). Nonetheless, risk as an important consideration, money, and other reported considerations and motivations, except for time, did not vary by income, employment, education, or previous experience. There were regional differences in both socio-demographic characteristics and factors important to participation decisions.


Healthy volunteers in phase 1 studies consider risks as more important to their enrollment decisions than the amount of money offered, although most are motivated to participate by the offer of money. Healthy volunteers are indeed low income, disproportionately unemployed, and have significant prior research experience. Yet these factors do not appear to affect either their motivations for participation or factors important to their research enrollment decisions.

Categories: Academic Writing