title: Personality characteristics of volunteers in Phase 1 studies and likelihood of reporting adverse events.
abstract: OBJECTIVE
  To evaluate the personality characteristics of a group of participants in Phase 1 studies and to study the relation between the personality traits and the adverse events during participation.
  
  
  METHODS
  Study population consisted of 139 healthy volunteers to Phase 1 studies. Personality was assessed through the Revised NEO Personality Inventory (NEO-PI-R) and adverse events were monitored during participation.
  
  
  RESULTS
  Participants showed lower levels of Neuroticism (p < 0.001), and higher levels of Extraversion (p < 0.001) and Openness to Experience (p < 0.001) than the norm. In the Neuroticism domain, participants were lower in anxiety (p < 0.001), angry-hostility (p < 0.001), depression (p < 0.001), self-consciousness (p < 0.001) and vulnerability (p < 0.001), and higher in impulsiveness (p < 0.001). All facets of the Extraversion domain and all facets but "openness to esthetics" of the Openness to Experience domain were higher (p < 0.001) in the participants in relation to the norm. Participants were significantly lower (p < 0.05) on the overall Agreeableness domain, however, they were remarkably higher in altruism (p < 0.001) and trust (p = 0.001). Participants did not differ from the norm in the overall Conscientiousness domain, but they scored higher in competence (p < 0.001), achievement striving (p = 0.001) and self-discipline (p < 0.001). Females showed to report significantly more adverse events than males, and extraverted subjects showed to report less adverse events than introverted subjects.
  
  
  CONCLUSIONS
  Participants who volunteer for Phase 1 studies, differ from the general population in their personality characteristics. Some personality characteristics may have an effect on the probability of reporting adverse events during participation. Therefore, defining a personality of a volunteer may assume significant importance in Phase 1 studies.
authors.affiliation: Department of Research and Development, BIAL (Portela and Co., SA), S. Mamede do Coronado, Portugal. luis.almeida@bial.com
authors.forename: L
authors.initials: L
authors.lastname: Almeida
authors.forename: A
authors.initials: A
authors.lastname: Falcão
authors.forename: M
authors.initials: M
authors.lastname: Vaz-da-Silva
authors.forename: R
authors.initials: R
authors.lastname: Coelho
authors.forename: A
authors.initials: A
authors.lastname: Albino-Teixeira
authors.forename: P
authors.initials: P
authors.lastname: Soares-da-Silva
mesh_terms: D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D017321:Clinical Trials, Phase I as Topic / Q000379:methods / Q000523:psychology*; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D018579:Patient Selection; D010551:Personality; D010555:Personality Inventory; D012737:Sex Factors