The Caregiver Activity Survey (CAS): Longitudinal validation of an instrument that measures time spent caregiving for individuals with Alzheimer's disease

Family members Incur substantial financial costs during the course of carin g for an Individual with Alzheimer's disease. Much of this cost Is associat ed with time spent in caregiving tasks, including supervision and communica tion with the patient, and assisting with activities of daily living. We ha ve previously reported on the cross sectional reliability and validity of a scale that measures time spent caregiving. the Caregiver Activity Survey ( CAS). This study extends our results to a longitudinal study of the validit y of the instrument. Forty-four outpatients with Alzheimer's disease Mho li ved with a primary caregiver were followed over a period of 1 year 6 months . At six month intervals. the patients were administered the Mini Mental St ate Exam (MMSE), Alzheimer's Disease Assessment Scale (ADAS). and the Physi cal Self Maintenance Scale (PSMS). Caregivers completed the GAS. Over time, the CAS correlated significantly with the MMSE (r = -0.58. p = 0.000). ADA S cognitive subscale (r = 0.56, p = 0.000) and PSMS (r = 0.49. p = 0.000). As patients declined. caregivers spent less time communicating with and mor e time supervising the patient. Excluding the communication Item, time spen t caregiving increased significantly over time. This prospective study long itudinally validates the CAS with Alzheimer's patients. Copyright RI 2000 J ohn Wiley & Sons. Ltd.