OBJECTIVES:

Many people with dementia in care homes have distressing and costly agitation symptoms. This study assessed whether the MARQUE (Managing Agitation and Raising QUality of LifE) intervention was cost-effective (as measured with quality adjusted life years (QALYs)) compared to treatment as usual (TAU).

METHODS:

This study was an eight-month cluster-randomised controlled trial that enrolled 404 residents (MARQUE=189; TAU=215) living in care homes.

Data on healthcare service use and prescriptions were collected at baseline and 8 months asking about the previous 4 months. QALYs were calculated using the EQ-5D-5L adjusting for baseline differences over 8 months between groups.

We used multivariate imputation by chained equation for missing data, generating 20 imputed data sets. For each data set we ran 1,000 bootstrap replications using non-parametric bootstrapping; results were combined to calculate the mean values for costs and utilities and the standard errors around the imputed values, used to calculate 95%CI around point estimates.

RESULTS:

Mean total cost per resident in the MARQUE group, including the cost of the intervention, was £1,379 (95%CI £1,041 to £1,718), compared with £1,175 (95%CI £917 to £1,433) in the TAU group, generating a mean difference of £204 (95%CI -£215 to £623; p-value=0.320).

Non-parametric bootstrapping after multiple imputation produced 0.346 (95%CI 0.330 to 0.362) QALYs in the MARQUE group and 0.332 (95%CI 0.322 to 0.342) QALYs in the TAU group, generating a mean difference of 0.015 QALYs (95%CI -0.004 to 0.034; p-value=0.127).

Combining the difference in costs and difference in QALYs, the mean incremental cost per QALY gained of the MARQUE compared to TAU was £14,064.

CONCLUSIONS:

This study showed that although the mean incremental cost per QALY gained is below the NICE threshold, it has a low probability (62%) of being cost-effective at a willingness-to-pay of £20,000 per QALY due to the wide confidence intervals for costs and QALYs.