Study designs of evaluations included in the review
Inclusion of studies was based mainly on the methods section of the trials. Included studies were all placebo controlled. When available, large, well controlled trials with appropriate statistical methodology were preferred.
Specific interventions included in the review
Donepezil compared with placebo. In four of the included studies, patients received oral donepezil 1 to 10mg once daily for 12 to 24 weeks followed by a 2- to 6-week single-blind placebo-wash-out period. In those patients receiving 10mg per day, treatment was initiated with the 5mg dosage and increased, after one week, to 10mg.
In a further three Japanese studies, two short-term trials (8 or 12 weeks duration) compared donepezil 2mg with 0.1mg once daily and donepezil 3 and 5mg once daily with placebo. The third, longer term trial (24 to 48 weeks) compared donepezil 2mg with placebo.
Participants included in the review
Patients with Alzheimer's disease (mild to moderate). Ages of participants in the included studies ranged from 50 to 94 years.
Outcomes assessed in the review
Cognition, global clinical function, activities of daily living, ability to perform complex tasks, quality of life, caregiver burden, and adverse events. Primary end points used to assess efficacy included the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), Clinician's Interview-Based Impression of Change (CIBIC plus), and Clinical Global Impression of Change (CGIC).
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the reviewers performed the selection.