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What "withdraw at any stage" means
Participants are entitled to withdraw from research at any stage, and must be told before they consent what the consequences of withdrawal will be (NS 2.2.20). The entitlement to withdraw is not conditional on giving a reason (NS 2.2.19). But NS 2.2.20 is a disclosure obligation, not a guarantee that data can always be retrieved or removed once given: it requires that participants be told the consequences of withdrawal in advance, not that withdrawal is always consequence-free.
NS 2.2.6(g) reinforces this distinction. Among the matters that must be communicated to participants is "the participant's right to withdraw from further participation at any stage, along with any implications of withdrawal and whether it will be possible to withdraw data" (NS 2.2.6(g)). The National Statement is explicit that data withdrawal may not always be possible; the obligation is to disclose this upfront, not to make it happen on demand.
Withdrawal from participation versus withdrawal of data
These are different things, and consent documentation should treat them separately. A participant can always stop participating further, for example by ending an interview or declining a follow-up contact, and researchers should ensure this carries no disadvantage (NS 2.2.19). Whether a participant's already-collected data can be removed is a separate, practical question that depends on how far the data has progressed through analysis, aggregation or de-identification.
Two illustrations are common in evaluation and social research:
- A community survey for a program evaluation aggregates 400 responses into a report. Three months after the report is finalised, a participant asks for their responses to be withdrawn. By this point their individual responses cannot be meaningfully separated from the aggregate analysis. Withdrawal from further contact presents no difficulty; withdrawal of the data already contributed is not possible.
- A focus group participant in a market research study later recognises a verbatim quote attributed to their participant type in a published report and asks for it to be removed. Once the report is finalised and in use by the client, removal may be impractical.
In both cases, the obligation under NS 2.2.20 was discharged at the point of consent, provided participants were told beforehand that this was the situation they were agreeing to. It is not created retrospectively by the withdrawal request.
What to put in consent documentation
Address this directly in the participant information sheet rather than leaving it vague or promising more than is deliverable. Explain both rights clearly and separately: the right to withdraw from the activity itself, and the more limited right to withdraw data, together with the point at which the latter becomes impracticable.
Where a fixed date is known, for example because data collection closes on a set date and analysis begins shortly after, use it: specificity gives participants a concrete window to act and reduces ambiguity about what has been promised. Where a fixed date is not known, for example in longer-running or iterative projects, referring to a project stage, such as commencement of data analysis for the phase in which the participant took part, is a reasonable and sufficient reference point.
What reviewers look for
When reviewing how a participant information sheet addresses withdrawal, reviewers typically check whether the form:
- distinguishes between withdrawal from participation and withdrawal of data;
- identifies a cut-off point for data withdrawal, whether a date or a project stage, rather than leaving it open-ended;
- explains the practical effect of aggregation or de-identification on the possibility of data removal; and
- uses realistic language, rather than promising unqualified data removal "at any time" where that promise cannot actually be kept.
A consent form that simply restates NS 2.2.20 without applying it to the specific project's data handling is unlikely to satisfy a reviewer. Renegotiation of consent during a long-running project is a related but distinct requirement: where the terms participants originally agreed to change, participants must be told and given the opportunity to continue or withdraw (NS 2.2.8).
Related resources
This page was last updated on 16 September 2026.
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This article makes reference to the National Statement on Ethical Conduct in Human Research 2025. It is intended as practical guidance and does not constitute legal advice.
AI Disclosure: Resources in this library were prepared using Large Language Models with input from Iris Ethics staff who guided the scope and design. Subsequent revisions and final versions were developed and approved by Iris Ethics staff.