Chapter 1: Introduction

Question 1

What are the four common features among definitions of epidemiology?

Answer 1

1. Focus on populations, not individuals
2. Distribution of disease
3. Causes (determinants/factors)
4. Intervention/prevention

Question 2

What are the objectives of epidemiology?

Answer 2

1. Identify the etiology or cause of a disease and the relevant risk factors
2. Determine the extent of disease found in the community
3. Study the natural history of disease
4. Evaluate new and existing preventative and therapeutic measures and modes of health care delivery
5. Provide the foundation for developing public policy

Question 3

What is the typical pattern of disease occurrence seen in developing countries?

Answer 3

Infectious disease

Question 4

What is the typical pattern of disease occurrence seen in industrialized countries?

Answer 4

Chronic disease

Question 5

Why is it important to identify subgroups in the population who are at high risk?

Answer 5

1. to help direct prevention efforts

2. to identify specific factors or characteristics that put them at high risk and then try to modify those factors

Question 6

What is primary prevention

Answer 6

Preventing the initial development of disease

Question 7

What is an example of primary prevention?

Answer 7

Immunization, reducing exposure to modifiable risk factors

Question 8

What is secondary prevention

Answer 8

Early detection of existing disease to reduce severity and complications

Question 9

What is an example of secondary prevention?

Answer 9

Screening for cancer

Question 10

What is tertiary prevention

Answer 10

Reducing the impact of the disease

Question 11

What is an example of tertiary prevention?

Answer 11

Rehabilitation following a stroke

Question 12

What are the two approaches to prevention?

Answer 12

Population-based and high-risk

Question 13

What is the population-based approach?

Answer 13

Applying a preventative measure is widely applied to an entire population

Question 14

What is the high-risk approach?

Answer 14

Applying a preventative measure to a high risk subgroup

Question 15

How do the two approaches to prevention compare logistically?

Answer 15

Population-based: typically inexpensive and non-invasive

High-risk: typically more expensive and invasive or inconvenient

Question 16

What are the two major steps in the epidemiological approach to identifying the causes of disease?

Answer 16

1. Determine whether an association exists between exposure to a risk factor and development of the disease
2. Determine possible causal relationship from patterns of the association

Question 17

Briefly describe the contribution of Ignaz Semmelweis to epidemiology.

Answer 17

He was the first to hypothesize that childbed fever was the result of poor hygiene on the part of physicians and students delivering children.

Question 18

Briefly describe the contribution of Edward Jenner to epidemiology.

Answer 18

He is credited with taking the first steps in smallpox vaccination through observation that milkmaids who contracted cowpox were immune to smallpox.

Question 19

Briefly describe the contribution of John Snow to epidemiology.

Answer 19

He made the connection between the quality of drinking water and the incidence of cholera.

Question 20

Static/Stationary Population

Answer 20

Membership eligibility is fixed; individuals cannot enter or leave the population once it is defined.

Question 21

Dynamic Population

Answer 21

membership eligibility is not fixed, individuals can enter or leave the population once it is defined.

Question 22

List some examples of defining characteristics of populations.

Answer 22

1. geographic location
2. time period
3. characteristics of people (e.g. age, sex, occupation)

Question 23

Total Population

Answer 23

all persons sharing a particular set of characteristics

Question 24

Reference/Source/Defined Population

Answer 24

all persons sharing a particular set of characteristics about whom you want to make inferences and from which you will sample for your study

Question 25

Study Population

Answer 25

all persons in your study

Question 26

External Validity

Answer 26

Generalizability; ability to apply the results of our study to the reference population