Lim YY, et al. - This study was performed to determine the association of age, β-amyloid (Aβ) level, and apolipoprotein E (APOE) ε4 with memory decline in a large group of cognitively healthy older adults. Prior work revealed that in nondemented older adults, Aβ and ε4 combined to influence memory decline. Researchers demonstrated that these effects could further exacerbate with increasing age. In order to determine the risk of memory decline associated with Aβ and ε4 at each age, the estimates provided could be used.