Epidemiologic Transition: Changes of fertility and mortality with modernization (3) Abdel Omran. The Epidemiologic Transition: A Theory of the epidemiology of population change. Milbank Quarterly. 1971;49:509-538 Lecture by Ronald E. LaPorte. Annotated Version on October 1, 2010. Omran has written several classic papers on the epidemiologic transition. For NCD epidemiology important insight can be gained by understanding this model. http://www.who.int/docstore/bulletin/pdf/2001/issue2/vol.79no.2.159-170.pdf Original Power Point file of this lecture

Charles Darwin Evolution of Species Abdel Omran Evolution of Disease Charles Darwin talked about the evolution of Species. Abdel Omran also dealt with evolution, but the evolution of diseases in populations over time. Charles Darwin Evolution of Species

Epidemiology Psychiatric Epidemiologists Diabetes Epidemiology Cardiovascular Epidemiology Cancer Epidemiology Infectious Disease Epidemiology Epidemiology an be categorized into many different silos. Omran argued that in order to understand the patterns of “our” disease, we also have to look at the origins, ups and downs of all diseases.

Instead at looking at individual diseases, we need to look at the patterns of diseases Diseases go up and down in relationship to each other, sometimes there may not be a biologic relationship but the diseases go up and down together, or predict each other over time.

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. A basic concept of the epidemiologic transition has been how the transition can explain population growth. It is mortality, not fertility that determines population growth. SES, mortality, and morbidity 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 pestilence the population on a reoccurring 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.

As can been seen in Japan, Since 1900 the birth rated exceeded the death rate, leading to rapid population gains. During WWII, the death rate skyrocketed, but shortly after this there was baby boom.

In Sweden a similar patter occurred, in the period of Pestilence and Famine, there was very little population growth, primarily due to rampant epidemics of disease. During the receding pandemic era, the death rate was still high, but epidemics were reduced resulting in increases in populations.

In the health transition one sees a rapid decline of infectious diseases followed by a growth of Non communicable diseases

For the European model the rapid rise in population growth due to declining death rates.

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. Most certainly developed countries have a lower life expectancy. However what is often missed is that for both developing and developed countries alike there has been over a 30 increase in life expectancy.

14 years 35 years In the 1950s there was a 35 year difference between developed and developing countries, now this has shrunk to only 14 years.

A second components of the Epidemiologic transition is the unmasking of chromic diseases.

The model seen in NY is a generalized model for almost all countries.

A clear example is that of Mexico, with declining infectious diseases and the rising chronic disease.

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

As part of the epidemiologic transition is the rapid increase in Aging populations world wide.

Global Homogenety of Mortality Patterns

With the epidemiologic transition, one also sees transitions with SES for risk factors, such as cigarette smoking

There also has been a rapid increase in nutritional change There also has been a rapid increase in nutritional change. Calories are cheap, which has been of benefit of improving immunology, however with cheap calories weight and the prevalence of obesity increases.

Epidemiologic Transition Infectious Diseases NCD Mortality Rates This schematic demonstrates the changes in infectious diseases, and noncommunicable diseases with increase SES Epidemiologic Transition

Death Rates for TB in England and Wales TB Bacillus Identified Chemotherapy BCG Vaccination There has been a rapid reduction, for example, of TB in England and many other countries. This could not have been the result of Chemotherapy or BCG Vaccination as the decline began way before vaccinations.

Death Rates for Measles in Children in England and Wales Immunization begun The same is true for measles, where there has been a rapid decline that is not related to immunization.

NIDDM CHD Trauma CA Mortality Rates Epidemiologic Transition

Taiwan has also show the epidemiologic transition with the rapid increase in life expectancy due to the reduced infectious disease

At the same time there was major changes in nutrition with rapid increase in meat and dairy intake

China is a prime example of the epidemiologic transition China is a prime example of the epidemiologic transition. Since 1945 life expectancy has raised almost 30 years, now life expectancy is not much different than the US

The Causes of death in the US and China are virtually identical

High Incidence of NCDs in Developing Countries Possible Infectious Etiology Macronodular Cirrhosis Hepatocellular Carcinoma Rheumatic Heart Disease Iron deficiency anemia Related to Nutrition Deficiency Endemic Goiter Malnutrition Related Diabetes. Developing countries have a very different pattern. Their diseases are primarily associated undernutrition and infection, whereas developing countries are related to overnutrition.

High Incidence of NCDs in Developed Countries Cardiovascular CHD Deep Vein Thrombosis Respiratory Emphysema Lung CA Female Genital Endometriosis Endometrial CA Breast Breast CA Fibrocystic Disease Male Genital Prostrate CA Metabolic NIDDM There is a pattern of diseases for non-communicable diseases in developed countries in contrast with developing countries.

Back to Nature A Healthier Diet, less saturated fats, more fiber Improved Physical activity A Healthier Diet, less saturated fats, more fiber Less Stress We have heard how we should get back to the good old days… But how good were they?

Nomads Farmers Urban 45 yrs 60 yrs 70 yrs Transition The good old days of nomadic existence had a remarkably lowlife expectancy.

USA 1960 Urban Rural rural urban Developing Countries In 1960, in developing countries most people lived in rural areas. Developing Countries USA

USA 2010 Urban Rural urban rural Developing Countries Now this has dramatically changed, the “mega” cities of developing countries, such as Mexico City, and Sao Paulo have rapidly emerged. Developing Countries USA

Causes of Death Developed Developing Age 15-44 Age 45-54 Age 15-44 Accidents CA CHD Age 45-54 Age 15-44 Accidents CHD CA Age 45-54 If one looks that the most productive segments of society in developing and developed countries, the causes of death are virtually the same.

Conclusion The epidemiologic transition ties together fertility with rise in SES. The Second component is that it present the idea that disease appears in populations like a symphony with disease rising and falling, all in relationship to each other

Review Questions (Developed by the Supercourse team) What might the epidemiologic transition tell us about the evolution of chronic diseases? Over the past 100 years, life expectancy and causes of death have become homogenous world wide. Why is this important? We would appreciate your help with evaluating the content of this course. Please send completed Evaluation Form to super1@pitt.edu  with the subject "chronic disease supercourse evaluation"    If you have any comments or questions, please send a message to super1@pitt.edu