Abstract

We report a mixed-methods process evaluation embedded within a randomised controlled trial. We aimed to test and refine a theory of change model hypothesising key causal assumptions to understand how the New Interventions for Independence in Dementia Study (NIDUS)-Family (a manualised, multimodal psychosocial intervention), was effective relative to usual care, on the primary outcome of Goal Attainment Scaling (GAS) over 1 year.