The Non-Linear Relationship between Education and Mortality

Bethany Everett, University of Colorado at Boulder
David Rehkopf, University of California, San Francisco

Much research has found a strong relationship between education and mortality. Methodologically, this has been accomplished by using a linear term or a series of dummy variables to measure the relationship between education and mortality, despite the fact that there exists evidence that the relationship is not linear, and may vary between sexes and race/ethnic groups. We assess the relationship between education and mortality using Cox proportional hazard models with a penalized spline on education. We find a linear relationship only among non-Hispanic whites. Among non-Hispanic blacks and foreign born Mexican men and women we see decreased mortality risk at both the low ends and high ends of education, with a mortality risk peak occurring between 9 and 12 years of education. This results provide important insights into how education operates across race/ethnic groups and its relationship to mortality.