Objectives: To investigate the relationship between activities of daily living (ADL) impairment and Alzheimer's disease (AD) severity in mild to moderately severe AD patients receiving the cholinesterase (ChE) inhibitor rivastigmine.
Methods: ADLs were evaluated using the Progressive Deterioration Scale (PDS). Disease severity was assessed with the Global Deterioration Scale (GDS). Patients were participants in one of three double-blind, placebo-controlled trials with rivastigmine.
Results: Baseline PDS scores differed significantly (P<.001) by disease severity. At Week 26, PDS declines from baseline for placebo patients were significantly different at all disease stages. Specific ADL affected were disease stage-dependent. Rivastigmine treatment (6-12 mg/day) resulted in total PDS scores being significantly improved compared with placebo at all disease stages, although the effect on individual items differed by severity.
Conclusions: ADL impairment differs across the stages of AD. Greater impairment in total ADL scores is observed with increasing severity of illness. However, the stage of illness determines the type of ADLs lost. Treatment response to rivastigmine occurs with mild, moderate and moderately severe AD, with the largest effect in patients with advancing severity of disease.