Inclusion of adults with conditions that have the potential to affect capacity and or communication in research:...

We aimed to: (A) describe researcher decision-making when including or excluding adults with conditions that have the potential to affect capacity and/or communication in research and (B) explore the underlying values and reasoning of stakeholders in research which falls under the provisions of the Mental Capacity Act, 2005.

The mixed-methods design included semistructured interviews with adults with conditions that have the potential to affect capacity and/or communication, supporters, researchers, research ethics committee members and an online survey with researchers. Triangulation was used to integrate the data and examine the complementarity of the findings.

England and Wales.

There were 61 participants who took part in semistructured interviews, of which 39 were adults with conditions with potential to affect capacity and/or communication, 6 were in support roles for adults with conditions with potential to affect capacity and/or communication (including family members and professionals in advocacy organisations), 8 were members of research ethics committees flagged under the Mental Capacity Act to review research where there could be issues of mental capacity and 8 were researchers with experience of working with adults with conditions that have the potential to affect capacity and/or communication. The online survey had 128 participants, researchers with experience of working with adults with conditions that have the potential to affect capacity and/or communication.

All stakeholders were supportive of the genuine inclusion of adults with conditions that have the potential to affect capacity and/or communication in research, and exclusion was seen as a form of discrimination. Many researchers were daunted by meeting the threshold within the legislation for including participants who may lack capacity.

Further training, expertise and resources are required to promote the successful inclusion in research of adults with conditions that have the potential to affect capacity and/or communication.