Randomized, Controlled Evaluation of a Prototype Informed Consent Process for HIV Vaccine Efficacy Trials

Background: Procedures must be developed and evaluated to ensure that valid informed consent is obtained from participants in future HIV vaccine efficacy trials.

Methods: Prospective, randomized, controlled evaluation of prototype informed consent procedures for future HIV vaccine efficacy trials among 4892 high-risk HIV-uninfected participants in the HIVNET Vaccine Preparedness Study. All VPS participants received HIV vaccine trial education at baseline and at study months 6, 12, and 18. In addition, 20% of participants ("intervention participants") were selected randomly to undergo at study month 3 the prototype informed consent procedures, which included reading or listening to an audiotape of a 35-page booklet and then participating in a 1:1 semi-structured educational session. Knowledge of 10 key HIV vaccine trial concepts was assessed at baseline and months 6, 12, and 18 by self-administered questionnaire and compared with knowledge among participants not selected to undergo the prototype procedures ("control participants").

Results: Knowledge levels were low among all participants at baseline (mean <5 correct responses); both intervention and control participants improved over time (to a mean of 6.9 and 7.6 correct responses for control and intervention participants, respectively, at month 18). Participation in the prototype informed consent process was associated with substantial and sustained increases in knowledge, beyond that experienced by control participants (OR ranging from 1.2-3.5, p<.05, for the 10 key knowledge items). The impact of the prototype process was similar across HIV risk groups and educational levels. Information regarding the unknown safety and efficacy of candidate vaccines at the time of initiation of a Phase III trial were most persistently misunderstood by both intervention and control participants.

Conclusions: High-risk populations with disparate educational backgrounds being targeted for future US HIV vaccine efficacy trials can be informed about such trials. Gains in knowledge are retained for at least 18 months. Issues related to the unknown safety and efficacy of candidate vaccines must be emphasized in future informed consent discussions.  

Anne Coletti
Abt Associates Inc.
55 Wheeler Street
Cambridge, MA 02138