Fig. 2.

Bar chart showing the sample size distribution between Under the Cutoff (UCo) and Above the Cutoff (ACo) populations as determined by individual Braak stages. Thereby five sets of cohorts are shown here as defined by Braak stages I to V. For instances, the first set of UCo and ACo was differentiated by Braak stage I; UCo_{≤Braak_I} (red colored bar) included those, which were graded 0 (i.e. no Alzheimer’s disease) and I; and ACo_{≤Braak_I} (green colored bar) included those, which were graded from II to VI, and so on. Among these five sets of cohorts, first three sets were named as assortment 1, 2 and 3, respectively and used in this study. These groups were selected for two primary reasons. (a) Sample sizes of UCo and ACo became non-comparable beyond Braak stage III, so we preclude the sets determined by Braak stage IV and V. (b) Although, the sample sizes between ACo and UCo was not comparable at Braak Stage I, we still investigated these two sets, because the diagnosis at the sub-clinical level can enable the caregivers an extra time to intervene.