Comparison of the design differences between the Ginkgo Evaluation of Memory study and the GuidAge study.

The epidemic of late life dementia, prominence of use of alternative medications and supplements, and initiation of efforts to determine how to prevent dementia have led to efforts to conduct studies aimed at prevention of dementia. The GEM (Ginkgo Evaluation of Memory) and GuidAge studies are ongoing randomized double-blind, placebo-controlled trials of Ginkgo biloba, administered in a dose of 120 mg twice per day as EGb761, to test whether Ginkgo biloba is effective in the prevention of dementia (and especially Alzheimer's disease) in normal elderly or those early cognitive impairment. Both GEM and GuidAge will also add substantial knowledge to the growing need for expertise in designing and implementing clinical trials to test the efficacy of putative disease-modifying agents for the dementias. While there are many similarities between GEM and Guidage, there are also significant differences. We present here the first comparative design and baseline data fromGEM and Guidage, two of the largest dementia primary prevention trials to date.