A hierarchical clustering analysis of 161 community-dwelling older adults distinguished three cognitive aging profiles using just three established neuropsychological tools — the Montreal Cognitive Assessment (with Memory Index Score), the Trail Making Test, and the Victoria Stroop Test. Across four cognitive domains (global cognition, memory, inhibition, and cognitive flexibility), the algorithm separated participants into normal cognition, probable executive MCI, and probable amnestic-plus-executive MCI clusters, with large between-group effect sizes for age, global cognition, and memory (partial η² 0.50–0.55).
The finding carries practical weight because amnestic MCI combined with executive dysfunction represents the highest-risk trajectory toward Alzheimer's and related dementias — yet no standardized community-level screening protocol currently exists. This clustering approach is notable for using only widely available, low-cost assessments that non-specialist practitioners could feasibly deploy in primary care or community settings. However, critical limitations temper enthusiasm: the sample of 161 participants is modest, none received a clinical MCI diagnosis, and the cross-sectional design means the clusters are probabilistic profiles rather than validated diagnostic categories. Longitudinal conversion rates to dementia remain unknown. The approach is methodologically incremental rather than paradigm-shifting, essentially systematizing existing tools rather than introducing novel biomarkers. As a preprint posted on medRxiv and not yet peer-reviewed, these findings require independent replication and prospective validation before informing clinical practice.
