Scholastic achievement: A multivariate analysis of nutritional, intellectual, socioeconomic, sociocultural, familial, and demographic variables in Chilean school-age children

Objective We determined relative effects of nutritional status, intellectual ability, exposure to mass media, and socioeconomic, sociocultural, familial, demographic, and educational variables on scholastic achievement (SA). Methods This was a cross-sectional study. Exposure to mass media and nutritional, intellectual, socioeconomic, sociocultural, familial, demographic, and educational factors, including approximately 2000 variables, were measured in a representative and proportional sample of 4509 school-age children from elementary and high schools in Chileʹs Metropolitan Region. The field study was carried out between 1986 and 1987, and data processing, which lasted 15 y, was completed in 2002. Results Within the total sample, intellectual ability, level of maternal schooling, head circumference-for-age Z score, book reading, in-door plumbing, level of paternal schooling, type of school, quality of housing, height-for-age Z score, and calcium intake were the independent variables with the greatest explanatory power in SA variance (r2 = 0.508). In most grades, IA was the independent variable with the greatest explanatory power in SA variance. In adolescents in their fourth year of high school and whose physical growth and intellectual development processes are consolidated, intellectual ability, age, head circumference-for-age Z score, book reading, type of school, and level of paternal schooling were the independent variables with the greatest explanatory power in SA variance (r2 = 0.60). Conclusions These findings show that SA is conditioned by multiple factors depending on the characteristics of school-age children, their families, and the educational system. Nutritional indicators of past nutrition are significantly associated with SA, especially head circumference-for-age Z score. This information may be useful for health and educational planning.