Verbal repetition in patients with Alzheimer's disease who receive donepezil

Abstract

Current outcome measures for Alzheimer's disease (AD) drugs have been criticized as insufficiently patient-centred. One commonly unmeasured goal of patients and caregivers is verbal repetition. We examined how often reducing repetition (of questions, statements or stories) was set as treatment goal, whether and when it responded, and how change in repetition correlated with change in other domains. This is a secondary analysis of the open-label Atlantic Canada Alzheimer's Disease Investigation of Expectations study of donepezil for mild-moderate AD in 100 community-dwelling people. Goal Attainment Scaling, an individualized account of the goals of treatment, was the primary outcome measure. Reducing repetition was a treatment goal in 46%, who were not systematically different from others. Of 18 patients in whom repetition improved for 9 months, 83% (15) showed a response at 3 months. Early (3-month) response correlated best with the overall level of goal attainment (r = 0.74) and changes in leisure activities (r = 0.69) and social interactions (r = 0.68) compared with changes in cognition (r = 0.44) or behaviour (r = 0.11). Correlations with the ADAS-Cog and MMSE change scores remained only modest (at 12 months = -0.25 and 0.19, respectively). Correlations with the CIBIC-Plus were higher (-0.47 at 3 months and -0.43 at 12 months). Diminution of repetition is common, and appears to mark response to cholinesterase inhibition in some patients. Responders generally also show improved cognition and function, perhaps as an aspect of improved executive function.