Education and Literacy as Risk Factors of Dementia after Stroke and Transient Ischemic Attack: NEDICES Study

Article type: Research Article

Authors: Contador, Israel^{a; *} | Alzola, Patricia^a | Bermejo-Pareja, Félix^{b; c} | del Ser, Teodoro^d | Llamas-Velasco, Sara^{b; c} | Fernández-Calvo, Bernardino^e | Benito-León, Julián^{b; c; f}

Affiliations: [a] Department of Basic Psychology, Psychobiology and Methodology of Behavioral Science, Faculty of Psychology, University of Salamanca, Spain | [b] Research Institute (Imas12), University Hospital “12 de Octubre”, Madrid, Spain | [c] The Biomedical Research Centre Network for Neurodegenerative Diseases (CIBERNED), Carlos III Research Institute, Madrid, Spain | [d] Alzheimer’s Disease Investigation Research Unit, CIEN Foundation, Carlos III Institute of Health, Queen Sofia Foundation, Alzheimer Research Centre, Madrid, Spain | [e] Department of Psychology, University of Cordoba, Cordoba, Spain | [f] Department of Medicine, Complutense University, Madrid, Spain

Correspondence: [*] Correspondence to: Israel Contador, PhD, on behalf of the Aging, Cognition and Health Research Group, Faculty of Psychology, University of Salamanca, Avda. de la Merced 109-131, ES-37005, Salamanca, Spain. Tel.: +34 923294500; Ext. 3248; E-mail: [email protected].

Abstract: Background:A protective effect of education on cognitive decline after stroke has been claimed, but evidence from prospective population-based cohorts is very limited. The differential role of literacy and education on dementia after stroke remains unexplored. Objective:This research addresses the role of education and literacy in dementia incidence after stroke and transient ischemic attack (TIA). Methods:131 participants with stroke or TIA were identified within the population-based NEDICES study (N = 5,278 persons). Participants were fully assessed at baseline (1994–1995) and incident dementia diagnosis was made by expert neurologists (DSM-IV criteria) after a mean follow-up of 3.4 years. Adjusted Cox regression analyses were applied to test the association between education, literacy, and dementia risk. Results:Within the 131 subjects with stroke or TIA, 19 (14%) developed dementia at follow-up. The Cox’s regression model (age and sex adjusted) showed that low education (HR = 3.48, 95% CI = 1.28, 9.42, p = 0.014) and literacy (HR = 3.16, 95% CI = 1.08, 9.22, p = 0.035) were significantly associated with a higher dementia risk. Low education was also associated with dementia when main confounders (i.e., cognitive/functional performance) were considered in the Cox’s model. However, after including stroke recurrence, only low/null literacy (versus education) remained as significant predictor of dementia. Finally, low/null literacy showed an effect over-and-above education on dementia risk when both factors were introduced in the adjusted Cox’s regression. Conclusion:These findings underline the importance of literacy to estimate cognitive decline after stroke in low-educated populations.

Keywords: Cognitive reserve, illiteracy, low education, stroke, transient ischemic attack

DOI: 10.3233/JAD-220109

Journal: Journal of Alzheimer's Disease, vol. 88, no. 1, pp. 291-299, 2022