Epidemology

Question 1

What is Epidemiology?

Answer 1

WHO definition:
Epidemiology is the study of the distribution and determinants of health-related states or events (including disease), and the application of this study to the control of diseases and other health problems

Question 2

3 Methodologies used?

Answer 2

1. Surveillance/Descriptive
2. Analytical
3. Experimental

Question 3

What are surveillance studies used for?

Answer 3

Used to study distribution

Question 4

What are Analytical studies used for?

Answer 4

used to study determinants or cause (etiology) of disease

Question 5

What are experimental studies used for?

Answer 5

used as trials for a new drug or therapy

Question 6

What are the 5 stages of of epidemiology study?

Answer 6

1. Have a question to address
2. Design and conduct a study
3. Collect data
4. Analyse and describe the data/results
5. Interpret and assess data for use (policy making or health intervention)

Question 7

Uses of epidemiological data (6)

Answer 7

• Can be used to study etiology (cause) disease, disorders, conditions, injury, mortality…
• Determine primary agent responsible for disease or causative factors
• Can help to determine mode(s) of transmission of disease
• Can help to determine contributing factors to disease
• Can identify and determine geographic patterns, incidence and prevalence of disease
• Data can help to plan and develop public health services, programmes and strategies

Question 8

5 Sources of epidemiological data

Answer 8

1. Worldwide: WHO
2. UK: Office for National Statistics and Public Health England
3. Europe: ECDC – European Centre for Disease Control
4. USA: NCHS at CDC
5. Public Health Research Database: useful site explaining importance of access to this type of data for Public Health

Question 9

What are descriptive studies? and what are they good for?

Answer 9

Based on PPT
Person – Place – Time
Good for e.g. 
	allocating resource, 
	planning public health programmes,
	developing hypotheses about health/disease

Question 10

What are Analytical Studies?

Answer 10

Analytic Studies 
Can find what gives rise to disease
Epidemiological Triad – HAE
Host – Agent – Environment
Look for determinants or etiology of disease
Good for testing hypotheses

Question 11

Define epidemic

Answer 11

rapid spread of disease to a population in a short period above what is expected

Question 12

Define Pandemic

Answer 12

often affects larger number of people than epidemic and is a widespread epidemic across a wider geographical area (often a continent or worldwide.

Question 13

Define Disease prevalence

Answer 13

Proportion (P) of a specific population with a disease (number at a specified time over population at specified time)
Measures disease burden
P = 0 to 1 x100 gives a %

Question 14

What is period prevalence ?

Answer 14

during a period

Question 15

What is point prevalence?

Answer 15

at one point in time

Question 16

Define Disease Incidence

Answer 16

Proportion of specific disease-free population (at risk) developing a disease in a specific period – I

Question 17

What is incidence rate or density?

Answer 17

Incidence rate or density accounts for fact that different sub-populations of the whole have varying times of being ‘at risk’ of disease during the period

Question 18

What is the difference between crude and specific rates of disease

Answer 18

Crude: uses the whole population without stratification into sub-groups

Specific: Can help to subdivide populations to interpret data such as into age ranges. This may unmask hidden complexity in the data