Efficacy of rivastigmine transdermal patch on activities of daily living: Item responder analyses

Objective: In Alzheimer's disease (AD), rivastigmine has demonstrated statistically significant efficacy versus placebo on cognition and activities of daily living (ADL). The aim of this retrospective analysis was to further evaluate the treatment effects of rivastigmine on individual ADL items. Methods: This exploratory analysis focused on the Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL) outcome from a large, international, 24-week, controlled trial of rivastigmine once-daily transdermal patch and twice-daily capsules in AD (CENA713D2320, NCT00099242). Percentages of patients "improving" or "not worsening" on individual ADL items were calculated and changes from baseline with rivastigmine versus placebo were evaluated. Results: Patients received rivastigmine patch (9.5 mg/24 h; n=247), capsule (12 mg/day; n=254), and placebo (n=281). Statistically significant changes from baseline in composite ADCS-ADL scores in both rivastigmine treatment groups versus placebo (p<0.05) had previously been reported. In this responder analysis of the subset of patients who showed baseline functional impairments on each item, statistically significant differences favoring rivastigmine were seen on the following functions: bathing, clearing dishes, obtaining a beverage, garbage disposal, traveling, shopping, writing, using household appliances, and talking about current events. A responder analysis of emergence of ADL impairment was not as sensitive to treatment effects. Conclusions: These findings suggest that rivastigmine may benefit specific ADL, particularly in patients who are already exhibiting functional impairment. Further research is required to improve understanding of how drugs such as rivastigmine exert their clinical effects.