Clinicians and clinical researchers routinely obtain human biological samples and store them for future research. Previously, samples were often stored and used without informed consent. Most investigators thought that the protections in place for research with human participants were not needed for research with human samples.

Recent commentators recognise the importance of informed consent for research with biological samples, but they disagree about when it is required and what types of consent should be obtained. Some argue that people should provide consent for each new study, at the time the study is proposed. Others support prospective consent, but they endorse different sets of options regarding the storage of samples, which investigators can use the samples, and what types of research can be performed.

This profusion of guidance has led to divergent practices,1 2 with one study finding that institutional review boards in the United States recommend “various consent options, all of which are different.”3 Such variation may undermine the scientific value of patients' contributed samples and greatly increase the costs of such research. Assessing whether people's views support one of the recommended options for consent could provide a solution to these problems.