Cost-effectiveness of exercise as a therapy for behavioural and psychological symptoms of dementia within the EVIDEM-E randomised controlled trial

Objective Although available evidence is modest, exercise could be beneficial in reducing behavioural and psychological symptoms of dementia. We aim to evaluate the cost-effectiveness of a dyadic exercise regimen for individuals with dementia and their main carer as therapy for behavioural and psychological symptoms of dementia. Methods Cost-effectiveness analysis within a two-arm, pragmatic, randomised, controlled, single-blind, parallel-group trial of a dyadic exercise regimen (individually tailored, for 20–30?min at least five times per week). The study randomised 131 community-dwelling individuals with dementia and clinically significant behavioural and psychological symptoms with a carer willing and able to participate in the exercise regimen; 52 dyads provided sufficient cost data for analyses. Results Mean intervention cost was £284 per dyad. For the subsample of 52 dyads, the intervention group had significantly higher mean cost from a societal perspective (mean difference £2728.60, p?=?0.05), but costs were not significantly different from a health and social care perspective. The exercise intervention was more cost-effective than treatment as usual from both societal and health and social care perspectives for the measure of behavioural and psychological symptoms (Neuropsychiatric Inventory). It does not appear cost-effective in terms of cost per quality-adjusted life year gain. Conclusions The exercise intervention has the potential to be seen as cost-effective when considering behavioural and psychological symptoms but did not appear cost-effective when considering quality-adjusted life year gains.