Cost-utility analysis of community occupational therapy in dementia (COTiD-UK) versus usual care: Results from VALID, a multi-site randomised controlled trial in the UK

Background A community-based occupational therapy intervention for people with mild to moderate dementia and their family carers: the Community Occupational Therapy in Dementia-UK version (COTiD-UK); and Treatment as usual (TAU) were randomly assigned to 468 pairs (each comprising a person with dementia and a family carer) in the Valuing Active Life in Dementia (VALID) randomised controlled trial (RCT). Objectives To compare the cost-utility of the COTiD-UK intervention compared to TAU, using data from the VALID RCT. Methods We performed a cost-utility analysis estimating mean costs and quality adjusted life years (QALYs) per person with dementia and carer for both treatments over a 26 weeks' time horizon based on resource use data and utility values collected in the trial. Results Taking the National Health Service and Personal Social Services perspective, including costs and benefits to the person with dementia only, measuring Health Related Quality of Life based on Dementia Quality of Life scale (DEMQOL), accounting for missing data and adjusting for baseline values, there was a significant difference in costs between COTiD-UK and TAU (mean incremental cost for COTiD-UK 784 (95% CI 233 pound to 1334)) pound, but no significant difference in outcomes (mean QALYs gained 0.00664 (95% CI -0.00404, 0.01732)). The Incremental Net Monetary Benefit (INMB) for COTiD-UK versus TAU was negative at a maximum willingness to pay for a QALY of 20000 pound (mean -651 pound, 95% CI -878 pound to -424) pound or 30000 pound (mean -585 pound, 95% CI -824 pound to -345) pound. Extensive sensitivity analyses confirmed the results. Conclusions This community-based occupational therapy intervention has a very low probability of being cost-effective.