Cost-effectiveness of Dementia Care Mapping in care home settings – Evaluation of a randomised controlled trial

Background: Behaviours such as agitation impact on the quality of life of care home residents with dementia and increase health care use. Interventions to prevent these behaviours have little evidence supporting their effectiveness or cost-effectiveness. We conducted an economic evaluation alongside a trial assessing Dementia Care Mapping™ (DCM) versus usual care for reducing agitation and highlight methodological challenges of conducting evaluations in this population and setting. Methods: RCT data over 16 months from English care home residents with dementia (intervention n = 418; control n = 308) were analysed. We conducted a cost-utility analysis from the healthcare provider perspective. We gathered resource use and utility (EQ-5D-5L and DEMQoL-Proxy-U) from people living with dementia and proxy informants (staff and relatives). Data were analysed using seemingly unrelated regression, accounting for care home clustering and bootstrapping used to capture sampling uncertainty. Results: Costs were higher in the intervention arm than control arm (incremental = £1,479) due in part to high cost outliers. There were small QALY gains (incremental = 0.024) in favour of DCM. The base case ICER (£64,380 per QALY) suggests DCM is not cost-effective versus usual care. With the exception of analyses excluding high cost outliers, which suggested a potential for DCM to be cost-effective, sensitivity analyses corroborated the base case findings. Bootstrapped estimates suggested DCM had a low probability (p<0.20 where λ=£20,000) of being cost-effective versus control. Conclusion: DCM does not appear to be a cost-effective intervention versus usual care in this group and setting. The evaluation highlighted several methodological challenges relating to validity of utility assessments, loss to follow-up and compliance. Further research is needed on handling high cost individuals and capturing utility in this group.