Frailty models in the analysis of mortality by education at late-adult ages in Turin. A survival analysis with period and cohort approach

This study investigates the role of unobserved frailty on the estimation of mortality differentials from age 50 on by education level. We used data of a 36 years follow up from the Turin Longitudinal Study containing 391,170 men and 456,216 women. We fitted survival analysis models with and without the unobserved heterogeneity component, controlling for mortality improvement from a cohort and a period perspective. We found that in the majority of the cases, the models without frailty estimated a smaller educational gradient then the models with frailty. During the post war industrialization Turin was the destination of many immigrants from the South of Italy. By adopting a period and cohort perspective and controlling for the individual region of birth we found that the migration flow is likely to have reduced male heterogeneity and the educational gradient.