It may not happen very often, but the basic principle of participants being free to withdraw from a research study is central to the idea of voluntary participation on the basis of informed consent.

It’s a month or so after you completed your research interviews and one of your participants is having second thoughts. They liked the attention you gave them, loved the free coffee and biscuits you provided, but now they’re not entirely happy with what they said and how you might use it. After a bit of scrabbling around, they find the information sheet and give you a call…

“I’d like to withdraw from the study please”

“Well, um…”

“It says here that I can withdraw at any point, without penalty”

“Ah yes, well you see, the thing is that we’re already doing the analysis…”

“But it clearly says AT ANY POINT!”

In the ethics process, we regularly find ourselves commenting on these issues of participant withdrawal, so here are a few pointers about how to avoid the common pitfalls.

Pitfall 1 – ‘withdrawal at any time’

It’s really important to allow participants to withdraw from the study, but you have to be realistic about what this means in practice. Obviously, they should be able to walk out of an interview or focus group if they’re not comfortable. And it’s good practice to allow participants to withdraw their data afterwards. But there has to be a time limit – it’s perfectly reasonable to set a time limit for withdrawal which provides sufficient time for participants to reflect after data collection, but is before you actually start analysis.

Possible indicator of participant withdrawal?

Pitfall 2 – walking out halfway through

Think about what will happen to data you have already collected if a participant withdraws from the study halfway through. In many cases, this will be relatively straightforward – if it’s a one-off interview and the participant runs away screaming after 10 minutes, you’d need an extremely good reason to keep any of the data you have already collected. But clearly it’s more complicated in longitudinal studies, where you may be collecting data at different time points, and potentially analysing data between waves of data collection. And there are many situations where a participant has withdrawn from the study (e.g. they’re not answering the phone), but they haven’t told you whether they want to withdraw their data. As with so many things, the answer is clear communication – you need to be specific in the information that you give to participants when they are consenting to take part, so that they know exactly how and when they can withdraw themselves and their data from the study.

Pitfall 3 – focus groups

So you’ve had an amazing focus group discussion and you’re really looking forward to analysing the data, when one participant decides to withdraw from the study. It might be relatively straightforward to delete everything they said from the transcript…but it might not. You’d need to be absolutely certain that you can separate their input from that of other focus group members, and that the rest of the data will make sense once you’ve chopped one person out. Again, clear communication is key – if you think it would be impossible to extract one person’s data, then be up front about that when people are consenting to take part.

(NB The ideas in these columns will not answer all of your ethics questions. For more information and up-to-date forms, always check the website. To learn more about ethics, use the online training module.)