Caregiver time use: An outcome measure in clinical trial research on Alzheimer's disease*

To assess whether unpaid caregiver time and paid professional time increase as cognitive impairment associated with Alzheimer's disease increases and to evaluate the utility of caregiver time as an additional outcome measure in clinical trial research of Alzheimer's disease.This was a 24-week, double-blind, multicenter, parallel-group, placebo-controlled study conducted at 17 clinical outpatient sites by Hoechst-Roussel Pharmaceuticals Inc. A total of 449 patients older than 40 years with probable Alzheimer's disease of mild to moderate severity (criteria of the National Institute for Neurological and Communicative Disorders and Stroke--Alzheimer's Disease and Related Disorders Association) entered the study, and 284 completed both baseline and week 24 data collection. A total of 160 caregivers completed time allocation surveys at baseline and at 24 weeks. Patients with Alzheimer's disease received 150 mg/day and 225 mg/day Velnacrine maleate (parallel-group treatment) and placebo. Cognitive function was measured with use of cognitive and noncognitive subscales of the Alzheimer's Disease Assessment Scale (ADAS). Unpaid caregiver and paid professional time use were measured with use of the Caregiver Activities Time Survey (CATS).Unpaid caregiver time per day increased significantly with cognitive impairment at baseline as measured by the ADAS cognitive and noncognitive components. Velnacrine therapy significantly improved cognitive function relative to placebo, and this was associated with decreased unpaid caregiving time at trend levels. Specifically, caregivers of patients in the high-dose velnacrine group (225 mg/day) experienced a partial release from their time involvements, especially in the area of patient supervision, by an average of 3.3 hours per day.To our knowledge, this study represents the first time that the ADAS has been linked to a caregiver outcome. Results suggest that unpaid caregiver time allocation is sensitive to changes in cognitive function and therefore may be useful as an additional outcome measure in clinical trials of pharmaceutical interventions for Alzheimer's disease.