Objectives: To report on a Numbers Needed to Treat (NNT) analysis of the literature identified through a systematic review of trials of cholinesterase inhibitors in Alzheimer's Disease.
Design: Search of Medline (1966-1998), EMBASE (1994-1999) and Psychlit (1974-1998) using the keywords cholinesterase and placebo dementia.
Settings: Double-blind, randomised, placebo-controlled trials.
Subjects: People with Alzheimer's Disease.
Interventions: Drug trials of acetylcholinesterase inhibitors (ChIs). Main outcome measuresAlzheimer's Disease Assessment Scale (Cognitive subscale), Clinician's Interview Based Impression of Change Plus, Mini Mental State Examination, Progressive Deterioration Scale.
Results: Small numbers of patients (in most cases between 3 and 7) need to be treated with appropriate dosages of ChIs to ameliorate the clinical symptoms, or postpone deterioration in one of them.
Conclusions: These small NNTs suggest that, despite their expense, the cholinesterase inhibitors have a valuable place in the current clinical management of AD.