Epidemiology and social causation of diseases

Question 1

What is epidemiology?

Answer 1

Epidemiology is the study of the frequency, distribution and determinants of disease and risk of disease in populations.

Question 2

What in particular are epidemiologists interested in?

Answer 2

Occurrence of disease categorized by time, place and person

Question 3

What do epidemiologists do?

Answer 3

Look at

• Trends over time and determine eg if number of cases has increased/decreased over time and the possible cause
• They look and see if particular areas have higher frequencies of a disease than others or if people with specific characteristics are more likely to get a disease
• Identify risk factors

Question 4

What is a risk factor?

Answer 4

An attribute or exposure (e.g. aspect of personal lifestyle, environmental exposure or inherited characteristic) that is associated with an increased risk of disease.

Question 5

Examples of risk factors?

Answer 5

XS alcohol intake= risk of cirrhosis, hypertension
Radiation leaks= thyroid cancer
BRCA1 mutation= Breast cancer

Question 6

Why is it important from an epidemiological perspective to identify, understand and characterize the relationship between exposure to a risk factor and subsequent risk of disease?

Answer 6

• It can provide the evidence for disease causation
• Important to quantify the potential exposure to risk factors in a population, in order to determine how best to mitigate exposure risk.

Question 7

What 2 terms are used to describe disease occurrence?

Answer 7

Prevalence

Incidence

Question 8

Incidence Rate?

Answer 8

The number of new cases of a particular disease, arising within a population, over a set period of time

Question 9

Incidence rate Equation?

Answer 9

Number of persons exposed to risk of developing that disease during that period of time

Question 10

Prevalence Rate?

Answer 10

Measures the number of cases that are already present in the population at, or a particular point in time, or over a predefined period of time.

Question 11

Prevalence Rate Equation?

Answer 11

Number of persons at risk of having the disease at that specified time

Question 12

How are both incidence and prevalence rate usually expressed?

Answer 12

Per 1000

Question 13

What does incidence not tell you about?

Answer 13

Number of people living with disease

‘Current level of disease in population’

Question 14

What essentially is prevalence?

Answer 14

A snapshot

It describes the number of people who are known to be living with the condition/illness at a certain point in time.

Question 15

What does Demography study?

Answer 15

Populations and their:

• Size and density
• Growth
• Age distribution
• Fertility
• Mortality
• Migration
• Vital statistics

Question 16

What is demography?

Answer 16

Study of populations

Question 17

Why is it important to understand population dynamics?

Answer 17

In order to plan and deliver health and social care services to a population in a way that best serves the population’s needs.

Question 18

What is population size dependent on?

Answer 18

Births, deaths and migration

Question 19

Population size equation?

Answer 19

P2= P1 + births+ deaths+ net migration

P2 is size of population at a given time
(P1 is size of population at start of period)

Question 20

What do population pyramids provide?

Answer 20

Summary of the age and sex composition of a country and captures information about current birth and death rate trends

Question 21

What kind of pyramid would a LEDC have?

Answer 21

A spike- high birth and death rate, high infant mortality

Question 22

What kind of population pyramid would a country have once conditions start improving?

Answer 22

A wedge- still a high birth rate but lower death rate due to better healthcare and sanitation- population size increases

Question 23

Population pyramid for a MEDC?

Answer 23

Barrel- low birth and death rate, population static in size, population in equilibrium

Question 24

Why are rates referred to and not numbers?

Answer 24

Both statistics are similar when considered per head of population.

Question 25

Equation to calculate crude birth rate?

Answer 25

Total mid-year population

Question 26

Crude death rate equation?

Answer 26

Total mid-year population

Question 27

How are birth and death rates expressed?

Answer 27

Per 1000 people

Question 28

Crude death rate?

Answer 28

Mortality rate for a whole population - does not take into account the composition of a population

Question 29

Why is standardization used?

Answer 29

To enable comparison of rates across populations.

Question 30

What do standardized rates of mortality permit?

Answer 30

Standardised rates of mortality permit comparisons of mortality between populations with different age profiles.

Question 31

What else can standardization be applied to?

Answer 31

Incidence and Prevalence rates

Question 32

Most common standardization methods?

Answer 32

Sex and age

Can either be direct or indirect

Question 33

Indirect standardization?

Answer 33

A common set of age-specific rates is applied to the populations whose rates are to be standardized. It essentially compares the expected rate with the observed rate. The simplest and most useful form of indirect adjustment is the Standardised Mortality Ratio.

Question 34

Direct Standardization?

Answer 34

A common age-structured population is used as standard e.g. that of the European Union.

Question 35

Health inequalities?

Answer 35

Differences in health outcomes

Question 36

What best summarized internal, external and physical well-being?

Answer 36

Dahlgren and Whitehead in 1992 using the determinants of health diagram

Question 37

What to remember as a doctor?

Answer 37

The population dimension when caring for your patients

How social and cultural context can help to explain disease distribution

Importance of public health in achieving disease prevention