APOE and dementia: In this large community-based old age cohort, greater variability in RT performance but not slower mean RT predicted all-cause mortality while adjusting for conventional mortality risk factors of age, sex, cardiovascular risk and APOE ɛ4 status and important potential confounders of low global cognition and prodromal dementia, both known to be associated with greater IIVRT [4, 35] and increased mortality risk in old age [12, 13, 36].