The Fourth Stage of the Epidemiologic Transition: The Age of Delayed Degenerative Diseases

Abstract

Gains in longevity in the United States since the mid-nineteenth century occurred as a result of an epidemiologic transition: deaths from infectious diseases were replaced by deaths from degenerative diseases. Recent trends in cause-specific mortality suggest a distinct new stage, one of postponement of degenerative diseases. Projections based on these data must be applied cautiously; their implication for health and social policies are likely to be profound.