The Chronic Disease Index: Analyzing Health Inequalities Over the Lifecycle

The rich live longer than the poor, but relatively little is known about the evolution of health inequality across the lifecycle. Using rich administrative data from the Netherlands, we develop an index of chronic disease burden based on the projected contribution to old-age mortality. Chronic conditions account for one-third of the mortality gap in old age. Using our index we demonstrate that health inequality arises much earlier in life; by age 35, the bottom half of the income distribution has the same disease burden as those age 50 in the top half. Approximately 60% of the divergence across income groups is due to low-income individuals developing chronic illness at a faster rate, rather than chronically ill individuals sorting into lower-income groups. Using linked health survey data, we then examine the contributions of various mediators to the incidence of chronic diseases over the life cycle. Socioeconomic and geographic factors explain most of the variation, while individual health behaviors play a moderate role. Our findings align with calls to target health policies toward early-life social determinants of health.