**Public and patient involvement (PPI):**
- Involve adults with LD, carers, and frontline staff in:
- Refining research questions and outcomes.
- Co-designing adapted materials (PIS, consent forms, visual tools).
- Advising on recruitment, data collection, and interpretation.
- Provide accessible feedback on study progress and findings (easy-read summaries, group feedback sessions).
**Recruitment and sampling strategy:**
- Identification: Clinicians and social care staff identify potentially eligible participants from caseloads.
- Staff introduce the study using brief, accessible information.
- With permission, researchers meet the person (and carers) to provide full information and assess capacity.
- Level of learning disability
- Living situation (supported living vs residential)
- Type of target behaviour (health vs social/functional).
- Months 1–3: Literature review; PPI workshops; finalise protocol and measures.
- Months 4–6: Ethics and governance approvals; develop materials; staff training on BCTs and research procedures.
- Months 7–18: Recruitment and data collection (quantitative and qualitative).
- Months 19–22: Data analysis and mixed-methods integration.
- Months 23–24: Write-up, dissemination, and implementation planning.
**Dissemination and implementation:**
- Presentations to organisational leadership and teams.
- Accessible summaries for service users and carers.
- Conference presentations, peer-reviewed publications, practice briefings.
- Translate findings into practical guidance, training modules, and tools for adapted BCTs across health and social care services.