How Shifts in Individual Health Have Changed the Nature of Mortality Risk

Duncan O. S. Gillespie, University of Sheffield
Tim Coulson, University of Oxford
Shripad Tuljapurkar, Stanford University

Public health policy should ideally be built from insights obtained from linking changes in individual-health to changes at the population-level. We investigated how individual health trajectories have shaped the dispersion of mortality over time. We exactly decomposed changes in population-level health into contributions from the individual-level processes that generate them. We applied this to the Framingham Heart Study. We investigated changes to systolic blood pressure and body mass index in relation to the use of anti-hypertension medication. Longitudinal changes have driven substantial shifts in population health. This has caused the population-level association between health and mortality to change over time, with shifts among non-medicated individuals having had the greatest influence. Our findings indicate the success of public health action to reduce systolic blood pressure. However, rising body mass index is shifting the burden of mortality to heavier individuals; this urges further public health action on the social determinants of health.