Education and the risk of physical disability and mortality among men and women aged 65 to 84: The Italian longitudinal study on aging

Background Most studies report that people with higher education enjoy better health and longer life. Although it is well known that most risk factors are more common among individuals with a lower level of education, the underlying mechanism of this association is not fully understood. The objective of this study was to assess the association between education, disability, and mortality. Methods. We analyzed data on 1,817 men and 1,643 women, aged 65-84 years, to assess the association of educational level with physical disability and mortality adjusting for age, sex, smoking habit, occupation, and major chronic conditions. Results. The association between educational level and disability was characterized by a dose-response effect, with the relative odds significantly decreased by about 30%, 60%, and 79% in those with 4 or 5, 6 to 8, and more than 8 years of education, compared to those with 3 or less years of education. Death rates were lower among persons with 4 or more years of education compared to those with less education. However, after adjusting for disability status, education was no longer associated with mortality (RR = 0.97, CI = 0.65-1.43). Conclusions. The strong association of low education with disability found in this study may explain the inverse association with mortality reported in previous studies. Disability, indeed, seems to be the mediator between education and mortality and might be due to the higher severity level of diseases, leading to death, in the lower educated group.