Resource utilisation and cost analysis of memantine in patients with moderate to severe Alzheimer's disease

Abstract

Background: Alzheimer's disease (AD) is a devastating illness that causes enormous emotional stress to affected families and is associated with substantial medical and nonmedical costs.

Objective: To determine the effects of 28 weeks of memantine treatment for patients with AD on resource utilisation and costs.

Study design and methods: Multicentre, prospective, double-blind, randomised, placebo-controlled clinical trial performed in the US. The Wilcoxon-Mann-Whitney test was used to examine the resource utilisation variables and logistic regression models were used for multivariate resource utilisation analyses. Analysis of covariance (ANCOVA) models (log and non-log) were computed to examine costs from a societal perspective. All costs were calculated in 1999 US dollars.

Study population: Outpatients with moderate to severe AD. Overall, 252 patients received randomised treatment, and 166 patients (placebo n = 76, memantine n = 90) formed the treated-per-protocol (TPP) subset for the health economic analyses, on which the main cost analysis was based.

Main outcome measure: Resource Utilisation in Dementia (RUD) scale, measuring patient and caregiver resource utilisation, and various sources for cost calculations.

Results: Controlling for baseline differences between the groups, significantly less caregiver time was needed for patients receiving memantine than for those receiving placebo (difference 51.5 hours per month; 95% CI -95.27, -7.17; p = 0.02). Analysis of residential status also favoured memantine: time to institutionalisation (p = 0.052) and institutionalisation at week 28 (p = 0.04 with the chi-square test). Total costs from a societal perspective were lower in the memantine group (difference dollars US 1089.74/month [non-overlapping 95% CI for treatment difference -1954.90, -224.58]; p = 0.01). The main differences between the groups were total caregiver costs (dollars US-823.77/month; p = 0.03) and direct nonmedical costs (dollars US-430.84/month; p = 0.07) favouring memantine treatment. Patient direct medical costs were higher in the memantine group (p < 0.01), mainly due to the cost of memantine.

Conclusion: Resource utilisation and total health costs were lower in the memantine group than the placebo group. The results suggest that memantine treatment of patients with moderate to severe AD is cost saving from a societal perspective.