Why healthy subjects volunteer for phase I studies and how they perceive their participation?

Eur J Clin Pharmacol. 2007 Nov;63(11):1085-94. doi: 10.1007/s00228-007-0368-3. Epub 2007 Sep 20.


Objective: To characterize the motivations and attitudes of healthy subjects who volunteer for phase I studies as well as their perception of the informed consent procedure and participation in the study.

Methods: Subjects (n = 136, 48.5/51.5% males/females, 26.9 +/- 5.5 years; 51.9% students, 42.2% employed, 5.9% unemployed) anonymously answered questionnaires regarding study participation and personality (Revised NEO Personality Inventory).

Results: Financial reward was the most important motivation and was most valued by subjects with a lower monthly income (p < 0.01) and lower education (p < 0.05). Personality traits correlated differently with the various motivators for participation. "Word-of-mouth" (mainly by ex-participants) was the source of information on the phase I study for 94.9% of the participants. Most (88.2%) subjects consulted other people (family member/partner, 53.3% of participants; friends, 40.0%; physician, 25.0%) before deciding to participate. In 80% of the cases, the people consulted recommended that the subject not participate, with the risk of serious complications being the main objection in 75.7% cases. The information provided was generally assessed favorably; 34.6% of subjects considered the discomfort caused by participation to be less than that originally reported during the consent procedure, 58.8% considered it to be identical and 6.6% considered it to be higher. Most of the subjects (81.6%) declared that they never felt at risk of a serious complication during their participation in the study, 16.2% occasionally felt that they were at risk and 2.2% felt that they were at risk for a significant period of time. Personality traits correlated with the decision to ask someone else's opinion, the manner in which information provided was rated and the perception of the risk taken during participation.

Conclusion: Financial reward as the main motivator for participation in phase I studies was less valued by healthy volunteers with a higher income and education. A subject's motivations and perceptions toward participation were found to be influenced by individual characteristics, including some personality traits.

MeSH terms

  • Adolescent
  • Adult
  • Clinical Trials, Phase I as Topic*
  • Decision Making*
  • Educational Status
  • Female
  • Healthy Volunteers / psychology*
  • Humans
  • Informed Consent / psychology*
  • Male
  • Middle Aged
  • Motivation*
  • Patient Selection
  • Personality
  • Reward
  • Risk Assessment
  • Socioeconomic Factors
  • Surveys and Questionnaires