The effect of donepezil therapy on health costs in a Medicare managed care plan.

The objective of this study was to estimate the ramifications of donepezil use on the health care costs of a large Medicare managed care plan. Patients with a diagnosis of Alzheimer's disease or related dementia were identified from the claims-and-encounter records of the plan. Costs for 204 patients identified as having Alzheimer's disease and who were receiving donepezil were compared with a control group of 204 patients with Alzheimer's disease who had matching characteristics, but who were not receiving therapy. After controlling for age, gender, pharmacy benefits, comorbid conditions, and complications of dementia, annual costs for medical services and prescription drugs were found to be $3,891 lower for the study group. Costs were $4,192 lower for patients receiving longer-term therapy (> or = 270 day supply of donepezil) and $3,579 lower for patients receiving shorter-term therapy when compared with controls. By improving cognitive and daily functioning, donepezil may lower costs by improving medical management.