APOE and Alzheimer disease: A Cox-proportional hazard regression model showed, after correcting for age, sex, and years of education, that the AD-RAI + (HR = 2.82, 95% confidence interval, 2.22–3.58, P < 0.001) and APOE-ε4 + (HR = 2.31, 95% confidence interval, 1.83–2.92, P < 0.001) were still associated with an increased risk of MCI to AD conversion, and there was no interaction between them.