Effects of disclosing financial interests on participation in medical research: a randomized vignette trial

Little is known about the effects of investigators' financial disclosures on potential research participants.

We conducted a vignette trial in which 470 participants in a telephone survey were randomly assigned to receive a simulated informed consent document that contained 1 of 2 financial disclosures (per capita payments to the research institution or equity ownership by the investigator) or no disclosure. The main outcome measures were trust in medical research and willingness to participate in a hypothetical clinical trial.

Participants in the equity group reported less willingness to participate than participants in the per capita payments group (P = .01) and the no disclosure group (P = .03). Trust in the investigator was highest in the per capita payments group and lowest in the equity group (P < .001). Trust among participants who received no disclosure was also greater than trust among participants in the equity group (P = .04) but did not differ significantly from trust among participants in the per capita payments group (P = .15). Participants in the equity group made 3 times as many negative comments as participants in the per capita payments group; and 10 participants in the equity group spontaneously said they would not participate in the hypothetical trial because of the financial interest, compared with only 1 such participant from the other groups.

Although investigators' financial disclosures in research do not substantially affect willingness to participate, potential research participants are more troubled by equity interests than by per capita payments.