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Question 1

What is epidemiology in public health?

Answer 1

Prevention, health promoting, social, behaviour

Question 2

What is epidemiology in academic setting?

Answer 2

Causal factors, biomedical, health and disease

Question 3

What characterizes preformal epidemiology?

Answer 3

Hygiene +sanitation, travelling: import/export disease, infectious diseases

Question 4

What characterizes early epi?

Answer 4

First prof in epi, non-communicable diseases (pellagra, vitamins)

Question 5

What characterizes classical epi?

Answer 5

Academice field, tabacco, study designs (case-control, cohort..)

Question 6

What characterizes modern epi?

Answer 6

• Theoretical basis in RCT
• Differentiation of expertise

Question 7

Some major triumphs in epi?

Answer 7

• Identification of water as reservoir and vehicle of diseases
• Identification of vectors (flies, mosquitos)
• Cigarette smoking
• AIDS syndrome caused by sexually-transmitted virus

Question 8

What is prevalence proportion? How do you calculate this?

Answer 8

proportion of people in a population who have the disease at a given point in time: No of people with disease/total no of people in population

Question 9

How do you call no of adults with disease in specific time point vs period?

Answer 9

Point/period prevalence

Question 10

What is the incidence proportion (IP)? How do you calculate this?

Answer 10

Proportion of population that develops a disease in a specified period. No of people who develop disease in a specified period/No of people at risk at the START of the period

Question 11

How do you calculate the incidence rate (IR)?

Answer 11

No of people who develop the disease in a specified period/total PERSON-TIME when people were at risk of getting the disease

Question 12

Characteristics of closed population?

Answer 12

• Fixed membership
• No-one can be added
• People may die, lost to follow-up
• Becomes smaller with time
• Everyone is followed
• Incidence proportion + incidence rate
• Prevalence

Question 13

Characteristics of open population?

Answer 13

• New members with time
• Move in and out of the area
• No remain about the same
• No follow-up when leaving
• Incidence rate
• Prevalence often not?

Question 14

How is prevalence related to incidence and duration?

Answer 14

● If incidence is low, and duration is long (chronic),
prevalence will be large in relation to incidence.
● If duration is short (due to recovery, migration or
death), prevalence will be small in relation to
incidence.

As a formula: P = IR x D
(assuming that incidence is low: stationary population)

Question 15

When is incidence used vs prevalence?

Answer 15

1. Incidence is generally
   used for acutely
   acquired diseases…

… prevalence is used for
more permanent states,
conditions or attributes of
ill-health

2. Incidence is more
   important when thinking
   of etiology of the
   disorder…

… prevalence when
thinking of societal
burden of the disorder
including the costs and
resources consumed as a
result of the disorder.

Question 16

IP (Incidence proportion) can only be calculated in a(n) …… population. Why? And what is a synonym for IP?

Answer 16

Closed. Because IP = onset/people @ risk. The persons in the numerator, those who develop disease, are all included in the denominator (the entire population). It is the risk, or average risk or attack rate.

Question 17

IR (Incidence rate) can be calculated in a(n) … population

Answer 17

Closed & open.