Prediction of cognitive test scores: a comparison of brain structure, health, demographic, and cognitive data across adulthood

Cognitive performance prediction may help identify early cognitive decline. However, the heterogeneity of research findings impedes the identification of key predictors. This study used 21,877 participants (25–74 years) from the German National Cohort (NAKO Gesundheitsstudie, NAKO) to systematically predict cognitive test scores based on brain structure, demographic, health-related, and cognitive data. Importantly, validation analyses were performed across study sites and external samples (1000BRAINS). Higher predictability was observed in the total sample compared to age-specific subgroups (10% difference in explained variance). Demographic (e.g. age) and cognitive data (e.g. memory) outperformed brain structure (e.g. grey matter volume) and health-related data (e.g. hypertension). Cognitive tests were differentially predictable, most evident between episodic memory and motor speed (R(2) ≤ 0.32 versus R(2) ≤ 0.18). Differences in predictability between age groups finally highlight the importance of comparing prediction outcomes between adult lifespan and age-specific groups to elucidate general and age-sensitive predictors of cognitive test scores.