Full information about trials might be given retrospectively to participants

Editor—One of the central issues in the debate about informed consent in randomised controlled trials¹ has been the ethics of withholding the fact of randomisation from participants—for example, in the trials of support after stroke² and of management of sore throat.³ Psychologists recognise that it is sometimes necessary to withhold full information from participants, to minimise bias. Our professional code of conduct (http://www.bps.org.uk/charter/codofcon.htm) states that in these situations we must “provide ... full information retrospectively about the aims, rationale and outcomes of the procedure as far as is consistent with a concern for the welfare of participants.” Maybe a similar requirement could be introduced for medical researchers. The planned debriefing of participants would avoid the potential distress of those who discover from sources other than the investigators that important information about the research they had participated in was withheld from them.⁴

The most practical option would be to include the debriefing information with a summary of research findings offered to the participants, with an invitation to contact the researcher for a verbal discussion if the participant wishes. The possible psychological harm that may result from partial informed consent has been much discussed.⁴ The introduction of debriefing may help to alert investigators to the existence and extent of any such harm. Formal assessment of participants’ feelings after debriefing, and research investigating lay views about informed consent in different types of trials, would provide additional evidence to help guide research practice.

I agree with Warnock that we need to “distinguish things that differ.”⁵ The introduction of debriefing, and research on patients’ views and experiences, would help us to do this. For example, do patients feel differently about being randomised to different treatments without full informed consent (as in the trial in sore throat²) than they do about being randomised to other, non-treatment interventions, such as additional social support,¹ information leaflets, or health promotion advice? Do participants believe that not being informed of randomisation is acceptable if they are assigned to the control group receiving routine care but not if they are assigned to the intervention group receiving a new type of care?

The answers to questions like these would help investigators to make their own informed decisions about the amount of information to provide at the time of consent.