Epidemiologic Transition: Changes of fertility and mortality with modernization Abdel Omran The Epidemiologic Transition: A Theory of the epidemiology of population change. Milbank Quarterly. 1971;49:509-538 Omran has writen several classic papers on the epidemiologic transition. For NCD epidemoilogy important insight can be gained by understanding this model.

Charles Darwin Evolution of Species Abdel Omran Evolution of Disease Charles Darwin Evolution of Species

The New NCD Epidemiology and Prevention Systems approach Disease Monitoring Telecommunications Backbone Deming approaches to Prevention

Epidemiology Psychiatric Epidemiologists Diabetes Epidemiology Cardiovascular Epidemiology Cancer Epidemiology Infectious Disease Epidemiology

Instead at looking at individual diseases, we need to look at the patterns of diseases

Mortality is the fundamental factor in the dynamics of population growth and causes of death. Mortality has no fixed upper limits. Thus if fertility approached its upper maximum, depopulation would still occur. It is mortality, not fertility that determines population growth. SES, mortality, and mobitity are tied together in a system of disease and population growth. To understand the system, it is essential to understand the total interrelationships.

During the epidemiologic transition, a long-term shift occurs in mortality and disease patterns whereby pandemics of infection are replaced by degenerative and man-made diseases... Omran argued that we can not view diseases in isolation. It is critical to look at the pattern of disease, not a single disease.

Age of Pestilence and Famine Characterized by high mortality rates, wide swings in the mortality rate, little population growth and very low life expectancy During the age of pestalence the population on a reoccuring basis is being decimated by epidemics of infectious diseases. The mortality rates drive the system. Life expectancy is low, fertility is high, but the high fertility rates are off set by very high mortality rates.

Age of Receding Pandemics Epidemics become less frequent, infectious diseases in general become less frequent, a slow rise in degenerative diseases begin to appear In this era, the epidemics of TB, plague, malaria, etc. begin to subside. The death rate goes down with little change to the fertility rates, thus population growth occurs. During this time one sees the beginning of non-communicable diseases.

The shifts in disease patterns in the 19th century were primarily related to changing SES. With the 20th Century more related with disease control activities independent of SES: e.g. Mexico, China In the early stages of the transition in the 19th century, the changing mortality patterns are closely associated with improvements in SES. However, in the 20th century major advances have been made by countries with a low socioeconomic status but with an effective public health system.

Stages of the Epidemiologic Transition Pestilence and Famine Receding Pandemics Degenerative and man-made diseases The three stages represent the beginning emergence of non-communicable disease.

Epidemiologic Transition in Developing and Developed Countries World wide this century has seen a very rapid improvement in life expectancy. With this improvement there has been major shifts in the causes of death.

14 years 35 years

Increasing Life Expectancy and Causes of Death 100 Other 80 60 Violence CHD 40 CA One of the most striking predictions by Omran is that given countries have the same life expectancy, there is very little difference in the causes of death. 20 Infection 40 44 48 52 56 60 64 68 72 76 Population Life Expectancy