The effect of cholinesterase inhibitors on decline in multiple functional domains in Alzheimer's disease: a two-year observational study in the Sunnybrook dementia cohort

BACKGROUND: Despite widespread use of second-generation cholinesterase inhibitors (CHEIs) for the symptomatic treatment of Alzheimer's disease (AD), little is known about possible long-term effects in different functional domains. This study seeks to assess change in activities of daily living (ADLs) over two years in AD patients treated with CHEIs matched to untreated patients in the same longitudinal cohort study. METHODS: This study is based on the two-year prospective cohort study at the Memory Clinic in Sunnybrook Health Sciences Centre, University of Toronto. Probable AD patients (N = 130: untreated = 65, treated = 65) underwent standardized neuropsychological assessments including the Disability Assessment for Dementia Scale (DAD), at baseline, one-year and two-year follow-up. Groups received a careful evaluation of comorbid illnesses, concomitant medication use, and vascular risk factors. RESULTS: At baseline, there were no significant differences in demographics and characteristics. Treated patients showed less decline in overall function and in instrumental and basic ADLs. Furthermore, less decline was seen in the overall scores for initiation and planning over two years with moderate to large effect sizes. CONCLUSION: These findings have clinical relevance since functional ability has been increasingly recognized as a key outcome variable in AD treatment. It is also of note that the subscores reflecting executive functioning appear to drive these beneficial differences.