A trial of consent procedures for future research with clinically derived biological samples

The aims of this study were to determine which consent procedure patients prefer for use of stored tissue for research purposes and what the effects of consent procedures on actual consenting behaviour are.

We offered 264 cancer patients three different consent procedures: 'one-time general consent' (asked written informed consent), 'opt-out plus' (had the opportunity to opt out by a form), or the standard hospital procedure (control group). The two intervention groups received a specific leaflet about research with residual tissue and verbal information. The control group only received a general hospital leaflet including opt-out information, which is the procedure currently in use. Subsequently, all patients received a questionnaire to examine their preferences for consent procedures.

In all, 99% of patients consented to research with their residual tissue. In the 'one-time consent' group 85% sent back their consent form. Patients preferred 'opt-out plus' (43%) above 'one-time consent' (34%) or 'opt-out' (16%), whereas 8% indicated that they did not need to receive information about research with residual tissues or be given the opportunity to make a choice.

The 'opt-out plus' procedure, which places fewer demands on administrative resources than 'one-time consent', can also address the information needs of patients.