Reframing the epidemiological transition as increasing returns to tackling aging-related diseases.

Global life expectancy has risen since 1973 from 58 to over 73 years, while the share of people aged 65 years and older has doubled to 10% and is projected to reach 21% by 2073. This shift is linked to an epidemiological transition from infectious to chronic disease. Here, using Global Burden of Disease data, we reframe this transition by statistically grouping diseases on the basis of their impact over the life cycle, yielding four clusters: infant, early-adult, later-adult and aging-related. We show aging-related diseases are the largest part of the current global disease burden and the greatest lifetime burden for a newborn, even in low-income countries. Aging-related diseases possess two distinctive properties: a tight link between mortality and morbidity, and increasing returns, whereby reductions in their prevalence makes further gains even more attractive. The implications of this recasting of the epidemiological transition for health systems and aging research are discussed.