DESCRIPTIVE EPIDEMIOLOGY for Public Health Professionals Part 1 Ian R.H. Rockett, PhD, MPH Department of Community Medicine West Virginia University School of Medicine Prepared under the auspices of the Southeast Public Health Training Center, University of North Carolina, Chapel Hill,

Learning Objectives 1.To introduce some key historical contributors to the evolution of epidemiology 2.To present basic models of disease and injury 3.To address data sources, classification, and measurement 4.To build a bridge between descriptive and analytic epidemiology

Performance Objectives 1.To be sensitive to the history of epidemiology against the background of broad population change 2.To identify mortality and morbidity data sources 3.To calculate basic measures 4.To generate hypotheses from descriptive data

POPULATION TRANSITIONS and HISTORY

The Big Population Picture Source: Joseph A. McFalls, Jr. Population: A Lively Introduction. Third edition. Population Bulletin 53(3); 1998: 38.

The Demographic Transition The demographic transition framework illustrates population growth in terms of discrepancies and changes in two crude vital rates – mortality and fertility (ignores the third component of growth, migration)

Source: Joseph A. McFalls, Jr. Population: A Lively Introduction. Third edition. Population Bulletin 53(3); 1998: 39.

Top 10 Causes of Death in the U.S., 1900

Top 10 Causes of Death in the U.S., 2000

Source: Ian R.H. Rockett. Population and Health: An Introduction to Epidemiology. Second edition. Population Bulletin 54(4); 1999: 9.

EPIDEMIOLOGY epi – upon demos – people logos – study The scientific study of the distribution and determinants of health-related states or events in specified populations, and the application of resulting knowledge to the prevention and control of health problems

Epidemiology as a Liberal Art An accessible low-technology science, which incorporates the “scientific method, analogic thinking, deductive reasoning, problem solving within constraints, and concern for aesthetic values” David Fraser, New England Journal of Medicine, 316(6); 1987:

Some Epidemiologic History

Hippocrates On Airs, Waters, and Places (5 th century BCE On Airs, Waters, and Places (5 th century BCE)

Hippocrates spearheaded a move away from looking to blame demons for disease and injury

FAST FORWARD

Enter John Graunt ( )  vocation – haberdasher (seller of men’s accessories)  avocation – father/founder of demography and epidemiology

Graunt counted rather than considered (Major Greenwood) Among his observations, he noted:  regularity of biological phenomena in the mass  that more males are born than females and more males die than females (annually)

Partial Translation  Ague = Malaria  Purples & Spotted Feaver = Meningococcal Meningitis  King’s Evil = Tuberculosis of the lymph glands of the neck

Age 17 th century 2002 London, England United States Population Survivorship: Two Populations

Miasmatists Vs Contagionists miasm – pathogenic emanation dispersed in the atmosphere (malaria – bad ‘air’) contagion – vehicle of person-to- person disease transmission (forerunner of germ theory )

Enter John Snow ( )

Spot Map of Fatal Cholera Cases in London, 1854 Source: Ian R.H. Rockett. Population and Health: An Introduction to Epidemiology. Second edition. Population Bulletin 54(4); 1999: 6.

Filippo Pacini,