Disease Progression in Mild Dementia due to Alzheimer Disease in an 18-Month Observational Study (GERAS): The Impact on Costs and Caregiver Outcomes

Abstract

Background/Aims: We assessed whether cognitive and functional decline in community-dwelling patients with mild Alzheimer disease (AD) dementia were associated with increased societal costs and caregiver burden and time outcomes. Methods: Cognitive decline was defined as a ≥3-point reduction in the Mini-Mental State Examination and functional decline as a decrease in the ability to perform one or more basic items of the Alzheimer’s Disease Cooperative Study Activities of Daily Living Inventory (ADCS-ADL) or ≥20% of instrumental ADL items. Total societal costs were estimated from resource use and caregiver hours using 2010 costs. Caregiver burden was assessed using the Zarit Burden Interview (ZBI); caregiver supervision and total hours were collected. Results: Of 566 patients with mild AD enrolled in the GERAS study, 494 were suitable for the current analysis. Mean monthly total societal costs were greater for patients showing functional (+61%) or cognitive decline (+27%) compared with those without decline. In relation to a typical mean monthly cost of approximately EUR 1,400 at baseline, this translated into increases over 18 months to EUR 2,254 and 1,778 for patients with functional and cognitive decline, respectively. The number of patients requiring supervision doubled among patients showing functional or cognitive decline compared with those not showing decline, while caregiver total time increased by 70 and 33%, respectively and ZBI total score by 5.3 and 3.4 points, respectively. Conclusion: Cognitive and, more notably, functional decline were associated with increases in costs and caregiver outcomes in patients with mild AD dementia.