Cost Effectiveness of Memantine in Alzheimer’s Disease
- 351 Downloads
Clinical trials with memantine, an uncompetitive moderate-affinity NMDA antagonist, have shown improved clinical outcomes, increased independence and a trend towards delayed institutionalisation in patients with moderately severe-to-severe Alzheimer’s disease. In a randomised double-blind, placebo-controlled, 28-week study conducted in the US, reductions in resource utilisation and total healthcare costs were noted with memantine relative to placebo. While these findings suggest that, compared with placebo, memantine provides cost savings, further analyses may help to quantify potential economic gains over a longer treatment period.
To evaluate the cost effectiveness of memantine therapy compared with no pharmacological treatment in patients with moderately severe-to-severe Alzheimer’s disease over a 2-year period.
A Markov model was constructed to simulate patient progression through a series of health states related to severity, dependency (determined by patient scores on the Alzheimer’s Disease Cooperative Study-Activities of Daily Living [ADCS-ADL] inventory and residential status (‘institutionalisation’) with a time horizon of 2 years (each 6-month Markov cycle was repeated four times). Transition probabilities from one health state to another 6 months later were mainly derived from a 28-week, randomised, double-blind, placebo-controlled clinical trial. Inputs related to epidemiological and cost data were derived from a UK longitudinal epidemiological study, while data on quality-adjusted life-years (QALYs) were derived from a Danish longitudinal study. To ensure conservative estimates from the model, the base case analysis assumed drug effectiveness was limited to 12 months. Monte Carlo simulations were performed for each state parameter following definition of a priori distributions for the main variables of the model. Sensitivity analyses included worst case scenario in which memantine was effective for 6 months and one-way sensitivity analyses on key parameters. Finally, a subgroup analysis was performed to determine which patients were most likely to benefit from memantine. Informal care was not included in this model as the costs were considered from National Health Service and Personal Social Services perspective.
The base case analysis found that, compared with no treatment, memantine was associated with lower costs and greater clinical effectiveness in terms of years of independence, years in the community and QALYs. Sensitivity analyses supported these findings. For each category of Alzheimer’s disease patient examined, treatment with memantine was a cost-effective strategy. The greatest economic gain of memantine treatment was in independent patients with a Mini-Mental State Examination score of ≥10.
This model suggests that memantine treatment is cost effective and provides cost savings compared with no pharmacological treatment. These benefits appear to result from prolonged patient independence and delayed institution-alisation for moderately severe and severe Alzheimer’s disease patients on memantine compared with no pharmacological treatment.
KeywordsMemantine Base Case Analysis Dependency Level Institutionalisation Probability Severe Impairment Battery
The funding for this project was provided by Lundbeck A/S and Merz Pharmaceuticals GmbH.
- 3.Reisberg B, Burns A, Brodaty H, et al. Diagnosis of Alzheimer’s disease: report of an International Psychogeriatric Association Special Meeting Work Group under the co-sponsorship of Alzheimer’s Disease International, the European Federation of Neurological Societies, the World Health Organization and the World Psychiatric Association. Int Psychogeriatr 1997; 9Suppl. 1: 11–38PubMedCrossRefGoogle Scholar
- 16.Souetre EJ, Qing W, Vigoureux I, et al. Economic analysis of Alzheimer’s disease in outpatients: impact of symptom severity. Int Psychogeriatr 1995; 7(1): 15–22Google Scholar
- 19.Michel JP, Zekry D, Mulligan R, et al. Economic considerations of Alzheimer’s disease and related disorders. Aging (Milano) 2001; 13(3): 255–60Google Scholar
- 28.National Institute for Clinical Excellence. Guidance on the use of donepezil, rivastigmine and galantamine for the treatment of Alzheimer’s disease. London: National Institute for Clinical Excellence, 2001 Jan. Technology Appraisal Guidance No. 19Google Scholar
- 36.Reisberg B, Mobius H, Stoffler A, et al. Long-term treatment with the NMDA antagonist memantine: results of a 24-week, open-label extension study in moderately severe to severe Alzheimer’s disease [abstract]. 8th International Conference on Alzheimer’s Disease and Related Disorders; 2000 Jul 20–25; StockholmGoogle Scholar
- 37.Netten A, Curtis L. Unit costs of health and social care 2000. Canterbury: Personal Social Services Research Unit, University of Kent, 2000Google Scholar
- 38.National Institute for Clinical Excellence. Incorporating health economics in guidelines and assessing resource impact. London: Guideline Development Methods: Information for National Collaborating Centres and Guideline Developers. National Institute for Clinical Excellence, 2004Google Scholar
- 43.Canadian Coordinating Office for Health Technology Assessment. Guidelines of economic evaluation of Pharmaceuticals: methods and guidelines. Ottawa (ON): CCOHTA, 1997Google Scholar