The Scope of Epidemiology
Study Questions and Exercises
- Using your own words, give a definition of epidemiology.
- Before you read Chapter 1, what were your impressions regarding the scope of epidemiology? Based on the material presented in this chapter, what topics are covered by epidemiology? That is, to what extent does epidemiology focus exclusively on the study of infectious diseases or on other types of diseases and conditions?
- How would the clinical and epidemiologic descriptions of disease differ, and how would they be similar? Relate epidemiology to the term population medicine.
- To what extent does epidemiology rely on medical disciplines for its content, and to what extent does it draw on other disciplines? Explain the statement that epidemiology is interdisciplinary.
- Describe the significance for the epidemiology of the following historical developments:
- associating the environment with disease causality
- use of vital statistics
- use of natural experiments
- identification of specific agents of disease
Explain what is meant by the following components of the definition of epidemiology:
- determinants
- distribution
- morbidity and mortality
6. The following questions pertain to the term epidemic.
- What is meant by an epidemic? Give a definition in your own words.
- Describe a scenario in which only one or two cases of disease may represent an epidemic.
- What is the purpose of surveillance?
- Give an example of a disease that has cyclic patterns.
- What is the epidemic threshold for a disease? In what sense is it possible to conceive of the epidemic threshold as a statistical concept?
7. Epidemiologic research and findings often receive dramatic media coverage. Find an article in a media source (e.g., from the Internet or in a specific publication such as The New York Times) on a topic related to epidemiology. In a one-page essay, summarize the findings and discuss how the article illustrates the approach of epidemiology to the study of diseases (health conditions) in populations.
8. During the next week, read and review health-related articles available on the Internet or in your local or national newspaper. Try to find the following terms used in newspaper articles; keep a record of them and describe how they are used:
- epidemiology
- epidemiologist
- infectious disease
- chronic disease
- clinical trial
- increased risk of mortality associated with a new medication
9. What is the definition of a natural experiment? Identify any recent examples of natural experiments. To what extent might changes in legislation to limit smoking in public places or to increase the speed limit on highways be considered natural experiments?
10. Review Exhibit 1-2, Snow on Cholera. What do you believe was the purpose of each of the following observations by Snow?
- “small white, flocculent particles” in the water from the Broad Street pump
- the location of cholera deaths as shown in Figure 1-18
- people who died avoided the pump on Marlborough Street and instead had the water from the Broad Street pump
- “the greatest number of attacks in any one day occurred on the 1st of September . . .”
- “On September 8th—the day when the handle of the pump was removed . . .” To what extent do you think removing the pump handle was effective in stopping the disease outbreak?
