CORRESPONDENCE Pharmacoeconomics 2000 Dec; 18 (6): 609-6121170-7690/00/0012-0609/$20.00/0

© Adis International Limited. All rights reserved.

Potential Savings in the Cost of Caring forAlzheimer’s DiseaseTreatment with Rivastigmine

A pharmacoeconomic analysis of rivastigminetreatment for Alzheimer’s disease by Hauber et al.[1]was recently published. As the first model to assaypotential cost savings of this treatment in the UShealthcare system, this analysis provides an impor-tant contribution to the literature. However, in aneffort to achieve appropriate standards for the phar-macoeconomic analysis of Alzheimer’s disease ther-apies, a few criticisms must be raised.First, the authors do not consider the cost of the

treatment itself in their study. Considering the sig-nificant cost of drugs in this class, this is an impor-tant component in any pharmacoeconomic analysisof Alzheimer’s disease drug therapy. Depending onthe cost of the drug, the economic impact of thetreatment could range anywhere from a cost savingto only a minor cost offset.Secondly, the authors make no attempt to assess

costs resulting from adverse effects of treatment.Adverse events can have a significant impact on thecost of treatment, as was the case with tacrine, whichrequired frequent monitoring of liver function.[2]For rivastigmine, costs associated with adverse ev-ents are likely to be substantial since high dose riva-stigmine treatment is associated with significant gas-trointestinal adverse effects in up to half of treatedpatients.[3,4] Rivastigmine treatment may also re-quire physician visits to titrate the dosage of thedrug. In addition to the direct costs associated withthese factors, decreased compliance because of ad-verse events[3,4] is likely to further affect potentialcost savings. Although these costs can be difficultto estimate, some effort should be made.Finally, the authors extend their model out to 2

years, based on only 26 weeks of clinical data.[3,4]It is impossible to predict whether the clinical ben-efits observed during 26 weeks of treatment wouldpersist at the later time-points. As such, the findings

reported for these time-points are limited. Whilethe authors point out that the model has been vali-dated with 1 year of nonblind follow-up trials,[5]data not collected in a double-blind fashion are likelyto be less reliable. Sensitivity analyses, similar tothose performed by Jönssen et al.[6] in the study ofdonepezil, could be performed to more accuratelyestimate economic results at later time-points.Due to the insidious nature of Alzheimer’s dis-

ease, it has been difficult to accurately estimate thecosts of the disease. Because drug treatments donot cure the disease, but rather slow the cognitivedecline associated with Alzheimer’s disease, eco-nomic analyses of these treatments are even moredifficult to perform. New therapies for Alzheimer’sdisease present healthcare providers and their pa-tients with a wider range of choices to manage thedisease. However, to allow healthcare providers tomake informed choices, it is imperative that stand-ards for these analyses are developed and consis-tently utilised.

Karen W. Linkins, PhDSenior ManagerThe Lewin Group

Falls Church, Virginia, USA

John R. Lloyd, BSPresident

JRL & Associates, LLCBenicia, California, USA

Gregory O. Hjelmstad, PhDSenior Consultant

JRL & Associates, LLCBenicia, California, USA

Holly J. Strausbaugh, PhDSenior Consultant

JRL & Associates, LLCBenicia, California, USA

References1. Hauber AB, Gnansakthy A, Snyder EH, et al. Potential savings

in the cost of caring for Alzheimer’s disease: treatment withrivastigmine. Pharmacoeconomics 2000; 17 (4): 351-60

2. Sramek JJ, Cutler NR. Recent developments in the drug treat-ment of Alzheimer’s disease. Drugs Aging 1999; 14: 359-73

3. Rösler M, Anand R, Cicin-Sain A, et al. Efficacy and safety of

rivastigmine in patients with Alzheimer’s disease: interna-tional randomised controlled trial. BMJ 1999; 318: 633-8

4. Corey-Bloom J, Anand R, Veach J. A randomized trial evaluat-ing the efficacy and safety of ENA713 (rivastigmine tartrate),a new acetylcholinesterase inhibitor, in patients with mild tomoderately severe Alzheimer’s disease. Int J Geriatr Psycho-pharmacol 1998; 1: 55-65

5. Fenn P, Gray A. Estimating long term cost savings from treat-ment of Alzheimer’s disease: a modelling approach. Phar-macoeconomics 1999; 16 (2): 165-74

6. Jönsson L, Lindgren P, Wimo A, et al. The cost-effectiveness ofdonepezil therapy in Swedish patients with Alzheimer’s dis-ease: a Markov model. Clin Ther 1999; 21 (7): 1230-40

610 Correspondence

© Adis International Limited. All rights reserved. Pharmacoeconomics 2000 Dec; 18 (6)