Intensive Interaction for children and young people with profound and multiple learning disabilities (INTERACT): study protocol for a cluster randomised controlled trial, economic evaluation and process evaluation.

BACKGROUND: Communication interventions can facilitate communication between people with profound and multiple learning disabilities (PMLD) and familiar partners such as family and educational setting staff, including speech and language therapists. Various communication interventions are routinely used but their clinical and cost-effectiveness are unclear. Intensive Interaction (II) is one intervention that focuses on early interaction abilities. II can be delivered by staff in educational settings and/or at home. Despite many settings already implementing II, staff are sometimes untrained or have not received up to date training, potentially leading to inconsistencies in how the technique is applied and the quality of the interactions. We will provide structured training in II to educational setting staff and parents/carers with coordinated activities developed jointly for each child/young person to be delivered within the educational setting and at home. This study aims to establish whether Intensive Interaction delivered within educational settings improves communication skills of children and young people with PMLD.

METHODS: A multi-site pragmatic cluster randomised controlled trial comparing usual care with Intensive Interaction and usual care. Clusters will be educational settings. This study will recruit 330 participants (aged 3-25 years) with PMLD from 66 educational settings within Great Britain. Each participant will have a corresponding teacher, parent/carer, and interventionist. Potential participants will be screened by their educational setting for eligibility prior to giving informed consent. Data will be collected at baseline, 32 weeks, and 52 weeks post-randomisation and will assess health and educational outcomes including participants' communication skills, behaviour, wellbeing, and quality of life. The primary outcome is communication skills, measured by the Communication Complexity Scale (CCS) at 32 weeks post-randomisation. Setting staff will video record an interaction with each participating child/young person. Communication will be coded by members of the research team blinded to allocation using the CCS.

DISCUSSION: This study addresses a much used but currently under-researched intervention and results will inform the support provided to children and young people with PMLD in their educational settings and at home.

TRIAL REGISTRATION: The trial was prospectively registered on the ISRCTN registry on 3rd May 2023 (registration number: ISRCTN81099965, https://www.isrctn.com/ISRCTN81099965 ).