When to rely on consent
Consent needs to be sought for any aspects of managing participation changes that have implications for participants’ confidentiality, or where planned trial processes might otherwise be considered by participants to be intrusive or burdensome (or not otherwise within participants ‘reasonable expectations’).
An example mentioned elsewhere in this guidance is where trial staff might contact people other than the participant in the case that trial staff and participants have lost contact with each other (see principle O4 – losing contact).
In some cases, it may be appropriate to seek others’ consent. For example, if trial staff would like to collect details of a primary contact, then it would be fair to ask for that person’s consent to involve them in the trial (although consent would not have to be the lawful basis for processing their personal data under the UK General Data Protection Regulation).
When it may be better not to rely on consent
Consenting to a ‘presumed ongoing consent’ approach: elsewhere in this guidance, the idea of a ‘presumed ongoing consent’ approach is suggested.
This can justify continuation of data collection or other low-impact aspects of participation until participants explicitly say they want them to stop.
Although this sort of approach needs explaining carefully to potential participants, and may not be considered acceptable by everyone, it is not advisable to rely on participant consent to apply it, i.e. to ask participants to consent to the consent approach. This would take a form like: “Do you consent to data collection continuing until you explicitly say you want it to stop?”
The ‘presumed ongoing consent’ approach aims to provide clarity where information is not available about participants’ wishes regarding specific aspects of trial participation.
This is necessary partly because trial participation often comprises a range of activities, some of which involve more active involvement from the participant than others.
The active aspects are more burdensome, tangible and obvious to participants, so it stands to reason that participants would be much more likely to say they want these to stop, and less likely to comment on the more passive aspects unless prompted to do so.
If we were to rely on participants’ consent to apply the presumed ongoing consent approach, the ongoing consent to the approach would likely be a ‘passive’ aspect of participation that participants might be less likely to spontaneously say they want to stop.
This could therefore be another point about which participants’ wishes were not known when they stopped or reduced their participation.
In that case, trial staff could decide to assume that consent to the presumed ongoing consent approach had been withdrawn. This would negate any benefits of the approach because any aspects of trial participation relying on the presumed ongoing consent would also then need to stop.
Alternatively, trial staff could decide to apply a presumed ongoing consent approach to the presumed ongoing consent i.e. assuming the consent approach remained valid until the participant explicitly said they no longer accepted it. This would call into question the value of asking for consent at all in this case.
Instead, we recommend being fully transparent about any presumed ongoing consent approaches and allowing participants to consent to trial participation – or not – on that basis.
Consenting to be asked for reasons behind participation changes: others have suggested that participants should be asked to give consent to be asked about why they want their participation to change.
We would not recommend this. It could increase the complexity of consent processes, and raises further complications at the time a participant wants to stop taking part in a trial.
For example, imagine if a participant were to say simply that they want to ‘withdraw from the trial’, having previously given trial consent that included specific consent to be asked for their reasons for wanting to stop.
In this case, it could be difficult to ascertain whether that previous consent to be asked for a reason still applied, or whether it had been withdrawn along with other elements of their consent.
Potentially a presumed ongoing consent approach could be applied, however we suggest it may be preferable to rely on the more general idea of assent, i.e. checking more informally whether the participant might provide a reason, but respecting their choice in any case.