The cost-benefit of cholinesterase inhibitors in mild to moderate dementia: a willingness-to-pay approach.
OBJECTIVE
This study aimed to measure the economic value of cholinesterase inhibitors when used to treat Alzheimer's disease using the willingness-to-pay (WTP) approach and the framework of cost-benefit analysis.


METHODS
A cost-benefit analysis using the WTP approach was employed. The study sample consisted of 28 nonprofessional caregivers of outpatients with mild to moderate dementia from Toronto, ON, Canada. The caregivers were presented with four scenarios. In the first scenario, scenario A, a hypothetical patient with mild dementia was stabilised with a cholinesterase inhibitor. In the second scenario, scenario A with adverse effects, the above patient (A) experienced adverse effects caused by the drug. In the third scenario, scenario B, the patient exhibited behavioural symptoms in addition to mild dementia, and both were stabilised with the drug. In the fourth scenario, scenario B with adverse effects, the above patient (B) experienced adverse effects caused by the drug. The caregivers were then asked what amount they would pay, in Canadian dollars, each year to buy the medication, assuming that they were the caregivers of the patient described. A multivariate regression analysis was performed to assess the relationship between the demographic data (including the caregiver's yearly income) and the WTP. The average WTP was also predicted for the general population and the elderly population of Canada using data from Statistics Canada, and these values were compared with the cost of the medication.


METHODS
Nonprofessional caregiver perspective. All monetary values are 1999 values unless otherwise specified.


RESULTS
The mean yearly WTP was $Can4540 (95% CI 2334-6746) for scenario A, $Can3686 (95% CI 1530-5842) for scenario A with adverse effects, $Can5003 (95% CI 2661-7345) for scenario B and $Can4486 (95% CI 2222-6750) for scenario B with adverse effects. The WTP decreased when drug adverse effects were present (significantly in scenario A; p = 0.04), but did not significantly increase when behavioural symptoms were present and stabilised. In all scenarios, caregiver yearly income was the only significant predictor of WTP, in the direction expected. For all scenarios, the calculated WTPs from the regression analysis using our sample mean, the average Canadian population data and the elderly population data were all higher than the yearly cost of the cholinesterase inhibitors, with the net benefit ranging from $Can1723 to $Can4508.


CONCLUSIONS
The results of the study, from a small sample of nonprofessional caregivers, revealed that the caregivers are willing to pay more for cholinesterase inhibitors than the drugs cost, even when the adverse effects of the drugs are taken into consideration. This indicates a net benefit for cholinesterase inhibitors in the treatment of mild to moderate dementia from a consumer's point of view.
Department of Psychiatry, HOPE Research Centre and Division of Clinical Pharmacology, Room FG 05, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada. Krista.Lanctot@sw.ca
Grace
G
Wu
Krista L
KL
Lanctôt
Nathan
N
Herrmann
Shehnaz
S
Moosa
Paul I
PI
Oh
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017028:Caregivers / Q000191:economics; D002800:Cholinesterase Inhibitors / Q000009:adverse effects / Q000191:economics* / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D003704:Dementia / Q000188:drug therapy / Q000191:economics*; D003710:Demography; D005260:Female; D017048:Health Care Costs; D006302:Health Services Research; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction / Q000191:economics; D011795:Surveys and Questionnaires
D002800:Cholinesterase Inhibitors