This is the protocol for a review and there is no abstract. The objectives are as follows:
Our primary objective is to determine the diagnostic accuracy of the APOE-ε4 allele in detecting AD dementia and other types of dementia in people with MCI in a primary care setting.
Our secondary objective is to investigate the following potential sources of heterogeneity of test accuracy, where reported:
characteristics of participants, namely, baseline MMSE score, age, and gender;
APOE-ε4 background prevalence;
length of follow-up; and