Cognitive health and protective factors: from a life expectancy approach

Abstract

Objective: 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.

Study design: 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.

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

Results: 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.

Conclusion: 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.

Keywords: Cognitive health; Cognitive impairment symptoms; Education; Latin America; Life expectancy; Older people; Physical activity.