Effects of education and word reading on cognitive scores in a community-based sample of Spanish elders with diverse socioeconomic status

Introduction. The influence of education and oral word-reading ability on cognitive performance was examined in a sample of 1510 nondemented elders differing in socioeconomic status (SES) from three Spanish communities. Method. All individuals were enrolled in the Neurological Disorders in Central Spain, a population-based epidemiological study in central Spain. They completed a detailed demographic survey and a short standardized neuropsychological battery assessing psychomotor speed, attention, language, and memory. The Word Accentuation Test (WAT) was used as measure of oral reading ability. The influence of education and oral reading on cognitive performance was determined by multiple linear regression models, first controlling for demographics (age and sex), and subsequently for the WAT score and education. The contribution of socioeconomic conditions was addressed by stratifying the sample into groups of high and low SES. Results. The WAT showed a significant independent effect on cognitive scores, generally greater than that predicted by demographics. The higher predictive power of oral word reading on cognitive scores compared to education was consistent across the three communities. Although the variance explained by WAT was very similar in areas with diverse SES (low vs. high), WAT scores accounted for slightly more variance in naming and memory tasks in low SES areas. In contrast, the variance explained by WAT was higher for verbal fluency and the Trail-Making Test in areas with high SES. Conclusion. Oral word-reading ability predicts cognitive performance better than years of education across individuals with different SES. The influence of WAT may be modulated by SES and cognitive task properties.