8440.01 Introduction to Epidemiology

Question 1

What is epidemiology?

Answer 1

• Distribution and determinants of disease frequency in human populations and the application of this study to control health problems
• allows us to solve problems, answer questions, and make decisions
• focus on making comparisons to establish cause-effect relationships
  
  • evaluate info
  • make good decisions to improve outcomes

Question 2

Determinants

Answer 2

• factors that influence if a disease occurs or not
  
  • healthy person to become sick
    
    • OR sick person to recover

Question 3

Disease frequency

Answer 3

• quantify disease occurrences in a population

Question 4

What should disease frequency take into account?

Answer 4

• # of people affected by the disease
• size of source population
• length of time population was followed

Question 5

What are the fundamental assumptions of epidemiology?

Answer 5

• Human disease does not occur at random
  
  • factors or determinants that can increase or decrease the likelihood of disease
• Factors or determinants (casual or preventative) can be identified by systemic investigations of populations or subgroups within populations

Question 6

Define a population

Answer 6

• group of people with common characteristics
  
  • ex: age, race, sex

Question 7

Define fixed population

Answer 7

• Permanent membership
• defined by an event
  
  • ex: Atomic bomb survivors

Question 8

Define Dynamic population

Answer 8

• transient membership
• defined by being in or out of a “state”
  
  • ex: residents of the city of greenville

Question 9

Characterize Proportions

Answer 9

• Proportion=A/(A+B)
• not dependent on time
• expressed as fraction or percentage

Question 10

characterize ratios

Answer 10

• Ratio=A/B
  
  • Numerator-meet criteria
  • Denominator-do not meet criteria
• ex: 2 female cases of major depression to 1 male case of major depression

Question 11

Characterize rate

Answer 11

• numerator:
  
  • only people who meet case definition
• Denominator:
  
  • people who do or do not meet case definition
• dependent on time

Question 12

Prevalence

Answer 12

• # of affected people present in the population divided by the # of people in the population