TY - INPR JF - Dementia ID - discovery10141403 Y1 - 2021/12/30/ UR - https://doi.org/10.1177%2F14713012211042466 TI - Co-designing complex interventions with people living with dementia and their supporters N1 - This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ AV - public A1 - Lord, K A1 - Kelleher, D A1 - Ogden, M A1 - Mason, C A1 - Rapaport, P A1 - Burton, A A1 - Leverton, M A1 - Downs, M A1 - Souris, H A1 - Jackson, J A1 - Lang, I A1 - Manthorpe, J A1 - Cooper, C KW - Co-design KW - dementia KW - interventions KW - public and patient involvement N2 - BACKGROUND AND OBJECTIVES: We engaged people living with dementia, family carers and health and social care professionals in co-designing two dementia care interventions: for family carers and people living with dementia (New Interventions for Independence in Dementia Study (NIDUS)-family and home-care workers (NIDUS-professional training programme). RESEARCH DESIGN AND METHODS: Over October 2019-March 2020, we invited public and patient (PPI) and professional members of our NIDUS co-design groups to complete the PPI Engagement Evaluation Tool (designed to assess engagement activities), and non-professional PPI members to participate in qualitative telephone interviews. We thematically analysed and integrated mixed-methods findings. RESULTS: Most (15/20; 75%) of the PPI members approached participated. We identified four themes: (1) Creating the right atmosphere: participants found group meetings positive and enabling, though one health professional was unsure how to position themselves within them; (2) Participants influencing the outcome: while most members felt that they had some influence, for one carer consultation seemed too late to influence; (3) Having the right information: several carers wanted greater clarity and more regular updates from researchers; (4) Unique challenges for people living with dementia: memory problems presented challenges in engaging with substantial information, and within a large group. DISCUSSION AND IMPLICATIONS: We reflect on the importance of providing accessible, regular updates, managing power imbalances between co-design group members with lived and professional experiences; and ensuring needs and voices of people living with dementia are prioritised. We encourage future studies to incorporate evaluations of co-design processes into study design. ER -