Development of an intervention programme theory to increase movement in care homes for people with cognitive impairment: Care homes achieving realistic movement strategies (CHARMS).

There is an increase in both the number of people living in care homes, and the cognitive impairments they experience. Some of these experiences of cognitive impairments can be improved by appropriate movement and physical activity interventions, delivered in ways which take into account an individual's preferences, needs and abilities. A clear intervention programme theory (how we expect an intervention to work) can improve effectiveness, acceptability, transferability and sustainability. We used a systematic framework (Six Steps in Quality Intervention Development) and a co-production approach, to develop an intervention programme theory for Care Homes Achieving Realistic Movement Strategies (CHARMS). We identified twenty factors contributing to low levels of physical activity and movement which we grouped into four categories for change: i) cultural/staff; ii) residents; iii) environmental and iv) policy/system. A theory of change was developed using these categories plus additional theories to create ownership. It became evident that the intervention (the theory of action) needed to include activities in all categories; intervening in just one category (e.g. providing weekly physical activity) was not sufficient in itself. Developing the programme theory enabled care homes to develop activities to meet their specific contextual needs and develop ownership of the process and the intervention.