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Important new information about changing study involvement

Message of thanks and appreciation for having taken part

The participant should have a brief, general message of thanks for their contribution to the study. Some participants who stop taking part early may feel that they have not made an important contribution or, depending on the circumstances of their stopping, that they have somehow ‘let the study down’. It is important that they are reassured that they have made an important contribution.

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If the message will be sent to participants who have contributed to the study for a long time or a very short time, make sure it is suitably generic (while avoiding the risk it is perceived as being meaningless). Alternatively, consider a few different template statements if you would like to communicate something slightly different to those who have made a larger contribution to the study.

There may sometimes be some sensitivities about ending participation, for example if the participant is angry or upset about some aspect of the study and has stopped taking part because of this. This needs to be considered when participants are contacted, but we still suggest that a message of thanks and appreciation is always important, regardless of any changes in participation.

Participants may have a variety of feelings about stopping participation. We suggest that it is not helpful for a written communication to reflect too much on how participants may or may not be feeling, as there is too much scope for it to be received in unintended and unpredictable ways. For example, statements about the possibility of negative feelings might be perceived as insensitive, or might even induce negative feelings in some participants. Statements encouraging positive feelings such as ‘pride’ in participation might be seen as patronising, or might negatively impact participants who do not feel this way. If there are opportunities for participants to talk to someone about ending their participation and how they feel about it, this could be signposted (see also below: “What support is available while I end my participation in the study?”)


Thank you again for choosing to take part in this study and for the time and effort you put into the study until now. By deciding to take part you have made an important contribution to improving the healthcare of patients like you in future.

Losing contact (where applicable)

Researchers may have a set process to follow when they cannot contact a participant. For example, they might make three attempts to contact a participant (possibly using different methods), and if none are successful then they will consider the participant to have stopped taking part, and make no further attempts (or no attempts until a later time when they might try again). A written communication could be sent when no further attempts will be made – if it is considered appropriate and if the participant’s contact details are considered still likely to be correct – to confirm to the participant what has happened. This can include that no further attempts will be made to contact them, or when further attempts might happen, if that is the plan.

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If the study has the ethical approval and participants’ consent needed to attempt other ways to get back in contact with participants, such as through contacting the participant’s GP, participants could be reminded of these in this communication.

The message could also include an invitation for the participant to get back in touch with the researchers if they want to, with a reminder of the contact details for the primary research contact (e.g. their study doctor or research nurse). Researchers might also think about how else to make it easy for participants to get back in touch, for example including a pre-paid, pre-addressed envelope for anything that might need posting back.

Finally, researchers might think about a simple way for participants to communicate that they (participants) want all their involvement in the study to stop, without having to discuss with anyone. This could include an email address, online form, or phone number for sending text messages. If there is anything like this in place, then the communication could mention it.


Unfortunately, we have not been able to get in touch with you since [date of last contact] about your involvement in the [study name] study. We therefore assume that you have stopped taking part in the study for now. This means:

  • You will no longer receive any study questionnaires
  • You will no longer receive any invitations to any hospital visits for the study for now
  • See below for what this means for the [study payments] you may still be owed

We hope you are doing as well as possible since your last involvement in the study. We would encourage you to contact your study doctor or nurse if you need anything from them, or to let them know how you are doing, if you are happy to do that. You can find their contact details [below].

As you have not specifically said you want to stop all your contributions to this study, we may try again in future to contact you or the doctors looking after you, to see how you are doing. You can ask for us not to do any of these things at any time, if you want to. Please just get in touch with your study doctor or nurse [add any alternative contact methods] and we will make sure you and your doctors are not contacted again about your involvement in the study.

You can find out more about the ways we may try to get back in touch in the information sheet you got before you took part in this study. They are:

  • If you do get back in touch with your study doctor or nurse and attend any routine hospital appointments, any relevant information from these appointments will still be used for the study.
  • We may get in touch with your GP to find out how you are doing.
  • We may try to get in touch with you again in future for the same reason.

Summarising exactly how the participant’s participation has changed: “How has my participation in the [study] study changed?”

Participation in many types of studies has several elements, and in some cases only some of these will have stopped. It is important that participants understand exactly how their participation has changed, and they should have this clarity as soon as possible. This includes where participants are considered to have stopped taking part because they have lost contact with the study (see above).

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It is important for the participant’s primary study contact to discuss this with them, if possible, to find out exactly what they want to do. Confirming this in writing provides helpful clarity for both the participant and all involved in running the research study. It also allows the participant to say if what is recorded does not actually reflect their wishes. If the study has an optional form or any other way for participants to clarify exactly what they want to do, this could be mentioned.

One way to show participants how their participation has changed is to display the range of types (or ‘levels’) of participation possible for the study and clearly indicate which are still applicable and which have stopped. The summary should be presented in a basic way and not specifically refer to a discussion between the participant and study team unless this has happened.

As mentioned above, it is essential that the information in this section is correct, so it may often be necessary for research site staff and research sponsors to work together to ensure this. It must also align with the content of the information sheet the participant was given before they agreed to take part in the study.


This is our understanding of what is happening with your participation in the [study name] study now:

  • You have stopped taking the study medication
  • You will no longer be asked to complete any study questionnaires
  • You won’t attend any more hospital visits specifically for the study
  • You are still happy for relevant information about you from future routine healthcare appointments to be used for the study
  • You are still happy for the information collected about you so far to be used for further research projects, as long as this is done in a way that means your identity is not shared with anyone outside the research team

If this does not look right, please contact your study doctor or nurse. Otherwise, we will assume that this information to be correct.

Remember that there are some limits on completely ending all your involvement in the study. You can find more information about these in [further information] and in the information you were given before you agreed to take part in this study. The key points are:

  • We need to keep the information that we have collected about you until now and use it in the study analysis.
  • The [biological samples] that you kindly gave as part of this study have now been analysed, so it is no longer possible to destroy them.
  • We are legally required to collect information about certain side-effects from the study treatment, if you happen to experience these in future.

Further contact about the study: “Will I be contacted again about this study?”

It is useful to be clear with participants if they will be contacted again about the study (unless the nature of their ongoing involvement in the study means it is obvious that they will be). This includes who would contact them, and what it might be about.

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If the participant has clearly opted out of all further communications, this could be confirmed here. However, it may still be in participants’ own interests, in some (rare) cases, to contact them about new information related to the treatments they have taken. This possibility should be made clear to them if it is not already clear in other sections of the communication.

All study participants should have the chance to receive the results of the study if they want them, regardless of how long they participated for. If there are plans to contact participants directly about this when the study results are ready, this should be mentioned, with any information already known about participants’ contact preferences.

If there are other, optional ways that study updates are being shared with participants (e.g. newsletters), this could be mentioned in case any participants would like to sign up.


As you have stopped taking part in the study, we will not need to contact you about the study again unless we learn anything new about the treatment you have received that you might need to know. We will also make sure you find out the results of the study, if you want to know them.

[Add anything else relevant to the study, for example if participants could still sign up to receive newsletters/updates about the study]

Please remember to tell your study doctor or nurse (or your GP) if your contact details change or if you move home. If we have your updated contact details, we can still contact you if we need to, and we can share the results of the study with you when they are ready.

Explaining why participation has stopped: “Why has my participation stopped?” (Where applicable)

Where some or all elements of participation have stopped because of a decision by someone other than the participant (e.g. their doctor), it will often be important to explain this verbally to the participant and give them a chance to ask any questions they may have.

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They should not hear about it first in writing unless they have lost contact with the study (see above). However, the reason for the decision should also be given in writing. It may also be helpful to give the date of the participant’s last involvement in the study, if they will be stopping most or all aspects of participation.

It is important that all communication about this does not alarm the participant if their participation stopped for reasons to do with their safety. They should be given adequate reassurance that their safety and wellbeing will be looked after, in any case.


Throughout your time taking part in this study, the doctors looking after your care have been regularly checking that it is still safe for you to continue taking the study treatment. They will continue to make sure all your treatments are safe for you to take after you stop participating in the study, as well.

As you will have been told by your study doctor or nurse, unfortunately it is no longer the best option for you to continue taking the study treatment. This decision was not taken lightly, but was taken in the interests of your health and wellbeing. Do talk to your doctor or nurse about this if you have any questions or concerns.

This does not mean your involvement in the [study] study has to end completely, if you don’t want it to. See [below] for more about your choices and about what aspects of your participation will continue.

Information about study payments/incentives/vouchers (may fit best with the information in this section, or in ‘other’ information, depending on the study)

It may be important to be clear about arrangements for any payments soon after the participant stops taking part, if it will likely be something they will wonder about. If this will be handled separately by the research sponsor or someone else, then the initial information given after the participant stops taking part could say that more information about payments will follow, and/or give details of who to contact in the meantime if they have any questions.

Clarifying participants’ options in relation to their participation: “What are my choices now about my involvement in the [study] study?”

It is good to give participants clear, understandable information about what their choices are about any possible further involvement in the study, building on the summary information given above. Unless some aspects of participation have been stopped by someone else to protect the participant, or the participant has lost the ability to make their own decisions, it should be up to the participant how their participation changes (within the limits of each study’s design).

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Their choices around reducing or stopping their participation should be clear from the start of the study and in any discussions with study research staff around the time they stop taking part. The written information can act as a back-up to this, and help participants with the sorts of questions they might want to ask.

Exactly what choices are available will depend on the study and possibly also on each participant’s circumstances. However, considerations will likely include each participant’s choices regarding their participation in the study, and regarding whether they want to be updated on the study progress and the results of the study.

Participants should also get information to inform these choices, including the pros and cons of different choices both from their perspective and from that of the study. However, care must be taken not to make participants feel any pressure to change their mind about any decision they have already made. It is important to provide this sort of content in the information participants get before they agree to take part in the study. They can then be reminded of it around the time they are deciding about stopping or reducing their participation in a study.


You have the right to stop taking part in any aspect of this study at any time, and without giving a reason if you don’t want to give one. Any decision you make about this will not affect your standard of care.

This means you can stop all your involvement in the study if you want to, although remember that there are some limits on ‘undoing’ things that have already been done. We explained these to you before you agreed to take part in the study, and we have reminded you in this message, as well.

This also means that you might be able to make further contributions to the study without giving as much of your time, if you want to.

Specifically, this means:

  • [Add study-specific details about what ‘reduced’ participation might be possible]

Your study doctor or nurse may have explained your options to you already, but feel free to get in touch with them using the contact details [below] if you want to hear more about this.

If you have already said you do not want to make any further contributions to the study, no one will ask you about this again.

Finally, it is up to you whether you want to receive updates about this study in future, including to find out the results of the study when they are available. See [above section on future contact] for more on this.