Service user (SU) and carer involvement in planning healthcare services and improving their quality is crucial and required by the NHS. Research has shown that SUs and carers can greatly benefit healthcare; however, effective involvement can be challenging due to barriers such as language, lack of training or support, and undervaluing the input of patients and the public compared to that of professionals.

The 4Pi framework sets out standards for good involvement practices by focusing on principles such as respect and inclusivity, shared purposes, diversity, accurate planning, and ensuring involvement leads to improvements in people's lives.

This study, funded by King's Health Partners, aims to take the 4Pi framework a step further by developing a questionnaire to evaluate how well patients and carers are involved in improving mental health services. The researchers will work closely with SUs and carers to create this questionnaire, with the ultimate goal to ensure that involvement in healthcare leads to real, positive changes for everyone involved.

The research questions for the study is: to what extent, from SUs and carers' perspectives, is the questionnaire understandable and successful in capturing the meaning of 4Pi domains?

To be eligible for the study, participants need to be at least 18 years old and have experience of involvement activities/projects in SLaM. Researchers, SUs, and carers will define the questionnaire to ensure it is understandable, comprehensive, and feasible; this will be done via virtual (or in person at Denmark Hill/King's College London campus depending on participants' preferences) group interviews. The questionnaire will then be piloted on a small sample of individuals, and the final questionnaire refined based on any potential additional feedback from them.

This study is part of the King's Improvement Science programme's research portfolio that is funded by King's Health Partners.

Inclusion Criteria:

1. be at least 18 years old;
2. have experience of being involved in service involvement activities in SLaM NHS Foundation Trust.

Exclusion Criteria:

a) No experience of being involved in service improvement activities.

Service users and carers with experience in service involvement activities.