Epidemiology

Question 1

Objectives of Epidemiology

Answer 1

• Identify the etiology or the cause of a disease and the risk factors (that which increases a persons risk for a disease)
• Determine the extent of disease found in the community
• Study the natural history and prognosis of the disease
• Evaluate both existing and new preventative and therapeutic measures and modes of health care delivery
• Provide the foundations for developing public policy and making regulatory decisions relating to environmental problems

Question 2

Epidemiology

Answer 2

study of the distribution and determinants of states of health and illness in human populations

Question 3

Rates

Answer 3

Primary measurement. Describes either the occurrence or the existence of a specific state of health or illness (incidence, prevalence, mortality)

Question 4

Endemic

Answer 4

Transmission occur, but the number of cases remains constant

Question 5

Epidemic

Answer 5

The number of cases increases (sharp rise)

Question 6

Pandemic

Answer 6

When epidemics occur at several continents - global epidemic

Question 7

Wheel of Causation

Answer 7

de-emphasizes agent/host, focuses more on genetic core, interplay of physical, biological, and social environments

Question 8

Epidemiological Triad

Answer 8

Classic model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, environment, not by any single factor

Question 9

Behavioral Risk Factor Surveillance Systems (BRFSS)

Answer 9

• CDC, telephonic survey
• measures diet, obesity, heart disease, etc.
• Healthy People 2020
• obesigenic neighborhoods, stores, workability, neighborhood safety, pollution - nurses use BRFSS to assess neighborhood

Question 10

How to calculate rates?

Answer 10

• All the events being measured should be included in the numerator
• Everyone included in the denominator should be at risk for the event in the numerator
• A specific period of time for the observations must be clearly indicated
• A rate is a fraction or a proportion (percent); MUST multiply by a rate, this removes the decimal points and makes the comparison of rates easier to interpret.

Question 11

Adjusted rate

Answer 11

measurement of the occurrence of the health problem or condition being investigated in the entire population - adjusting for confounding #s, age, race, etc.

Question 12

Crude rate

Answer 12

measurement of the occurrence of the health problem or condition being investigated in the entire population

Question 13

Incidence rate

Answer 13

measure of the probability that people without a certain condition will develop that condition over a period of time - think occurrence

Question 14

Prevalence rate

Answer 14

measures the number of people in a given population who have an existing condition at a given point in time - think existence

Question 15

Period Prevalence

Answer 15

indicates existence of a disease during a specific period of time, i.e. who has asthma within the last month

Question 16

Point Prevalence

Answer 16

refers to existence of a disease at a specific point in time, i.e. those who currently have asthma

Question 17

Specific rates

Answer 17

small subgroups; indices of the health of the community, region, or country include comparisons of general mortality rates and maternal infant rates

Question 18

Ratio

Answer 18

a fraction that represents the relationship between two numbers

Question 19

Relative risk ratio

Answer 19

ratio of the incidence rate in the exposed group and the incidence rate in the nonexposed group; i.e. smokers versus non-smokers

Question 20

Sensitivity

Answer 20

ability of the test to detect cases of a disease correctly

Question 21

Specificity

Answer 21

how good is the test at detecting the absence of a disease correctly

Question 22

Sensitivity and Specificity Calculation (box)

Answer 22

Top left corner: True positives (have the disease)
Bottom left corner: False negatives (have a false negative - they have the disease)
Top right corner: False positive (test positive without the disease)
Bottom right corner - True negative (do not have the disease)

Sensitivity: Number of true positives/(number of true positives + number of false negatives)

Specificity: Number of true negatives/(Number of true negatives + number of false positives)