The Moderating Effect of Sex on the Association between Education and Cognitive Impairment in Older Koreans: Analysis of Korean Longitudinal Study of Ageing Data

Abstract

Objectives: In traditionally developed countries, the protective role of higher education on cognitive impairment differed between men and women. This study investigated the moderating impact of sex on the relationship between cognitive function and educational level in older Koreans, who may have experienced inequality in access to educational opportunities in the past.Methods: This study used data from the 2018 Korean Longitudinal Study on Aging (KLoSA), a nationwide panel survey of community-dwelling older adults. Cognitive impairment was defined as a Mini-Mental State Exam (MMSE) score below 24. In univariate analyses, the χ2 test was used to examine the relationship between MMSE and each of sociodemographic and behavioral variables. Multiple logistic regression models were implemented to examine the association between MMSE score and educational level controlling for covariates. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated.Results: A total of 5,793 respondents were analyzed; 31.53% received no or only primary education. Individuals with up to primary education were more likely than those with college or higher education to have cognitive impairment (OR = 3.31, 95% CI = 3.29-3.34, p< 0.001). The association between lower educational level and cognitive impairment was stronger for women than for men; OR was 4.58 for women (95% CI = 4.52-4.65) and 2.98 for men (95% CI = 2.95-3.00).Conclusions: Lower education was associated with increased risk of cognitive impairment and the protective role of education in cognitive function was stronger in women than in men.