Known as the epidemiological transition, this shift is highly correlated with changes in personal and collective wealth (the economic transition), social structure (the social transition), and demographics (the demographic transition). Omran (1971) provides an excellent model of the epidemiological transition that divides it into three basic ages: pestilence and famine, receding pandemics, and degenerative and human- created diseases (table ). Olshansky and Ault (1986) add a fourth stage: delayed degenerative diseases. The consistent pattern formost high-income countries going through the epidemiological transition has been initially high rates of stroke, mostly hemorrhagic. Only in the third phase, with the presence of increased resources, but coupled with increased diabetes and smoking rates and adverse lipid.
