Cohorts with volunteer participants are based on consent. Usually, this is broad consent, meaning consent to the general aims of the cohort. However, the European Data Protection Board (EDPB), in its guidelines on consent, recommends that consent should be for a specific study protocol. This would seem to exclude using cohort data for where the aims are broadly defined such as into factors which contribute to the onset of a very generically described disease, such as cancer, and for improved treatment once it has occurred. 

There are several possible ways to bridge the gap between broad and specific consent. One of them  is to implement granular consent. It is unclear how often this has been attempted in cohorts and if so, what the outcome was, and what proportion of participants dropped out because they either did not agree to the study, or had lost interest in researching the specifics of each new study or in looking at the notification of a new (sub) study.

Another solution could be for the research community to propose an alternative to specific consent for the EDPB’s consideration, such as ‘consent to governance’. Participants then agree to the way how decisions about new studies are made and communicated to them. Yet, there are no guidelines based on practical experiences, as to how such an alternative governance model could be implemented.