Recall of disclosed apolipoprotein E genotype and lifetime risk estimate for Alzheimer's disease: the REVEAL Study.

Purpose: To determine whether individuals recall their apolipoprotein E genotype and numeric lifetime risk estimates after undergoing a risk assessment for Alzheimer's disease.

Methods: One-hundred and four participants underwent Alzheimer's disease risk assessment that included disclosure of apolipoprotein E genotype and a numeric lifetime risk estimate.

Results: At six weeks and one year post-disclosure, 59% and 48% of participants, respectively, recalled their lifetime risk estimate, and 69% and 63% recalled their apolipoprotein E genotype. Participants were more likely to remember their genotype than numeric lifetime risk estimate at one year (P < 0.05). Apolipoprotein E epsilon4-positive participants had better recall of their genotype at both time points (P < 0.05). Participants were more likely to recall whether they carried the "risk-enhancing form of apolipoprotein E" than their specific genotype (P < 0.05).

Conclusions: These data suggest that apolipoprotein E genotype, especially the presence of an epsilon4 allele, is more memorable than a numeric risk estimate for Alzheimer's disease. Participants recalled genotype information in a more simplified, binary form. Health professionals testing for complex disorders such as Alzheimer's disease must find an appropriate balance between communicating risk in an understandable format and addressing the probabilistic nature of the information.