Research protocol for a complex intervention to support hearing and vision function to improve the lives of people with dementia.

Background: Hearing and vision impairments are among the most common and disabling comorbidities in people living with dementia. Intervening to improve sensory function could be a means by which the lives of people living with dementia may be improved. However, very few studies have tried to ameliorate outcomes in dementia by improving sensory function. This paper describes the multi-step development of a new intervention designed to support hearing and vision function in people living with dementia in their own homes. At the end of the development programme, it is anticipated that a 'sensory support' package will be ready for testing in a full scale randomised controlled trial.

Methods: This programme is based on the process of 'intervention mapping' and comprises four integrated steps, designed to address the following: (1) scoping the gaps in understanding, awareness and service provision for the hearing and/or vision impairment care needs of people with dementia using a systematic literature review and Expert Reference Group; (2) investigating the support care needs through a literature search, stakeholder surveys, focus groups, semi-structured interviews and an Expert Reference Group, leading to a prototype sensory support package; (3) refining the prototype by additional input from stakeholders using focus groups and semi-structured interviews; and (4) field testing the draft intervention using an open-labelled, non-randomised feasibility study, integrating feedback from people with dementia and their significant others to develop the final intervention ready for full scale definitive trialling. Input from the 'patient and public voice' is a cornerstone of the work and will interlink with each step of the development process. The programme will take place in study centres in Manchester, Nicosia and Bordeaux.

Discussion: Quantitative and qualitative data analyses will be employed, dependent upon the sub-studies in question. Data from the steps will be integrated with consideration given to weighting of evidence for each step of the programme. This programme represents the logical development of a complex intervention to fulfil an unmet need. It is based on a theoretical framework and will lead to a subsequent full scale efficacy trial. The challenges in integrating the data and addressing the contextual issues across study sites will be scrutinised.