Authors' objectives: The aim of this report is to review economic evaluations of drugs presently available in Canada for the treatment of mild-to-moderate Alzheimer's disease (AD).

Authors' results and conclusions: Ten studies were identified that met the inclusion criteria. Seven studies evaluated donepezil and three evaluated rivastigmine. The seven studies on donepezil included three cost-effectiveness analyses (CEA), two cost-utility analyses (CUA) and two cost-analyses. The three CEA studies had a time horizon of five years, while the two CUA studies used time horizons of 18 months and 12.5 years. The three economic evaluations examining rivastigmine were CEA and all had a time horizon of two years. In three of the seven donepezil studies, donepezil was deemed to be the dominant strategy (produced a better outcome at lower cost) over no treatment. In the remaining four studies, donepezil was cost neutral. In particular, two U.S. studies showed no significant cost advantage to use of donepezil therapy versus no therapy. Sensitivity analyses demonstrated that the CEA and CUA models were generally robust, but were dependent upon some critical assumptions. These assumptions included the relative benefit of the drug beyond the six-month trial, the validity of the Mini Mental State Exam (MMSE) as a meaningful outcome measure in the CEA studies, validity of the Health Utility Index in one CUA analysis and the appropriateness of using cross-sectional data to forecast long-term cost savings. All the studies which examined rivastigmine showed cost savings. However, two of the three studies did not include the cost of the drug therapy, which is considerable. The largest cost savings were obtained by treating patients with AD of mild severity for a longer period (two years). The model used for the three analyses of rivastigmine is dependent on some critical assumptions including the assumption that delays in disease progression will not be affected by life expectancy and the appropriateness of cross-sectional data to forecast long-term savings.

Authors' recommendations: Donepezil and rivastigmine are associated with either a slight increase or a slight decrease in overall costs while producing a better clinical outcome for patients with mild-to-moderate AD. However, in even the most optimistic scenarios, the length of time gained in non-severe AD is very small. In addition, cost savings occur primarily due to a reduction in informal care costs and delays in institutionalization: the former is difficult to measure and there is no evidence yet that either donepezil or rivastigmine have significant impact on the latter.

Authors' methods: Systematic review

Project Status: Completed

URL for project: https://www.ccohta.ca/

Year Published: 2000

URL for published report: n/a

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Canada

Organisation Name: Canadian Coordinating Office for Health Technology Assessment

Contact Address: 600-865 Carling Avenue, Ottawa, ON K1S 5S8 Canada. Tel: +1 613 226 2553, Fax: +1 613 226 5392;

Contact Name: requests@cadth.ca

Contact Email: requests@cadth.ca

Copyright: Canadian Coordinating Office for Health Technology Assessment