Public Health

BACKGROUND: Cognitive impairment (CI) is considered a risk factor for premature mortality. However, it has not been extensively studied in Latin American populations (LATAM). We investigated the association between CI and all-cause mortality in four LATAM cohorts from Chile, Costa Rica, Mexico and Puerto Rico. METHOD: This prospective cohort study included up to n = 12,990 participants aged ≥60 years from four studies: the Chilean National Health Survey 2009-2010 (CNHS n = 1,226), the Costa Rican Study on Longevity and Healthy Aging 2004-2006 (CRELES n = 1,898), the Mexico City Prospective Study 2015-2019 (MCPS n = 6,448), and the Puerto Rican Elderly: Health Conditions 2002-2003 (PREHCO n = 3,418). Data on all-cause mortality was collected until 2020, 2010, 2022, and 2013, respectively. The Mini-Mental State Examination (MMSE) assessed cognitive performance (higher scores indicate better performance). A CI case was determined according to the MMSE cut-off criteria established by each cohort. The Kaplan-Meier estimator and multivariable Cox proportional hazards models were performed. Results were expressed as HR (95%CI) per cohort and in meta-analysis. RESULT: The mean age across the cohorts ranged from 69 years (IQR 64-76) in CNHS to 73 years (IQR 67-81) in CRELES. The follow-up period varied between 3.69 years in CRELES and 8.88 years in CNHS. The prevalence of cognitive impairment (CI) ranged from 4.5% in PREHCO to 40.9% in MCPS. The mortality rate ranged from 8.9% in CRELES to 34.7% in CNHS. Subjects with CI had a lower probability of survival than those with normal cognition. The risk of mortality associated with cognitive impairment was 66% (HRCNHS=1.66, p <0.001), 53% (HRMCPS=1.53, p <0.001), and 58% (HRPREHCO=1.58, p = 0.01). For CRELES, no significant association was observed (HR=1.22, p = 0.25). The meta-analysis across cohorts yielded a pooled risk of all-cause mortality of 52% (HR=1.52; p <0.001). CONCLUSION: LATAM adults aged ≥60 with CI have a lower survival probability and higher mortality risk. Higher MMSE scores are protective against premature mortality. These results are consistent across cohorts and in meta-analysis.