Cognitive health and protective factors: from a life expectancy approach

This study aimed to quantify the impact of gender and key proxies of cognitive reserve in later life, such as education and physical activity, on cognitive impairment-free life expectancy (CIFLE), and measure the significant regional disparities in cognitive health within Chile.

A panel dataset was employed to track the cognitive states of 1,959 Chilean individuals aged 60 years and over, who were interviewed in private households between 2017 and 2019.

Multistate modelling was applied to calculate CIFLE, total life expectancy, and the impact of protective factors on the lifespan and by geographical macrozone.

Higher education was associated with an average increase of 4.7 years in CIFLE and 4.5-year gain for women. Notably, physical activity demonstrated a powerful compensatory effect, adding 5.5 years of CIFLE for women with lower educational attainment, thus acting as a key mechanism to reduce gender gaps. The study's primary contribution is the quantification of profound territorial inequalities: older adults in regions outside the metropolitan area faced an up to 30% higher risk of cognitive impairment at older ages. National averages were found to mask these divergent local realities Geographic differences suggest a more advantageous situation in cognitive health for women in the metropolitan region than in other macrozones.

This study provides the first subnational quantification of years with better cognitive health in Chile, revealing that territorial disparities are a critical dimension of health inequality. The findings offer a direct evidence base for National Plan of Dementia in Chile and the National System of support and Care, demonstrating the urgent need to move beyond a top-down approach and implement targeted, region-specific public health interventions to promote equitable cognitive aging.