Epidemiology Overview

Question 1

What are the 6 main elements of the Population Approach to epidemiological study?

Answer 1

1. What is the burden of a particular disease?
2. Who is at high risk of the disease?
3. What is the cause of a disease?
4. How can the disease be prevented?
5. What treatment is effective?
6. How should treatment services be organised for the population?

Question 2

Give an overview of the burden of disease and The Clinical Iceberg model

Answer 2

Burden of disease: Most commonly assessed through impact on Mortality and Morbidity

Iceberg Model: There is more unknown disease than known disease (like an iceberg, mainly below water level….)

Unknown disease tends to be milder than the known disease

Therefore:
Amount of disease underestimated
Overall severity overestimated

-to assess the total amount of disease, need a survey of the wider population, not just those seeking care…

Question 3

Give an overview of assessing who is at high risk (2)

Answer 3

Four common factors:

• Age
• Gender
• Social class
• Ethnic origin

Does it occur in particular:

PERSONS?

PLACES?

PERIODS (OVER TIME)?

NB: Make sure to always view in context of total sample size, causality vs correlation etc.

Question 4

Give an overview of identifying causes of disease (3)

Answer 4

Needs evidence that exposure (to something) is associated with disease….

Comparative studies (based in the population) ask:

1. Is exposure associated with increased risk of disease (compared with unexposed)?
2. Do people who have the disease have increased previous exposure (compared with people without disease)?

Effective identification and avoidance of causes and behaviours can lead to effective Prevention of Disease (4)

Question 5

What type of trials are used to Identify effective treatment of diseases? (5)

Answer 5

Randomized controlled trials (RCTs)

Question 6

Identify 4 key considerations in determining Optimal Disease management in the wider society (6)

Answer 6

1. How should health services be organised to provide effective treatment efficiently, fairly and at the lowest possible cost?
2. Are all the people who can benefit from a beneficial intervention receiving it? (if no, who is not doing so?)
3. Is anyone receiving ineffective or harmful interventions?
4. How can health provision be improved/optimised?

Question 7

Give a definition of Epidemiology:

Answer 7

• The study of the distribution and*
• determinants of health and disease in human*
• populations*

Question 8

Give a definition of Public Health (Donald Acheson 1988):

Answer 8

• The science and art of:*
• • prolonging life*
• • preventing disease*
• • promoting health*
• (in the population)*
• by the organised efforts of society*

Question 9

Explain how epidemiological study can inform and affect our understanding of

Answer 9

Diagnosis

• Is this the most likely cause of symptoms?
• Is a diagnostic test valid?

Cause

• Why did this patient get this diagnosis at this time in this society?

Consequences

• What is the prognosis, and what factors affect it?

Treatment

• What treatment is effective for this patient?

Question 10

What is the formula for determining disease rate?

Answer 10

Rate = #Number of Cases / #Population at Risk

Answer 11

Prevalence rate (proportion)

Number of cases (old and new)

Population at risk

Incidence rate

Number of new cases in a specified time

Population at risk

(per period (e.g. a year))

Mortality rate

Number of (new) deaths in a specified time Population at risk

(per period (e.g. a year))

Question 12

What is the difference between a disease rate and a disease risk?

Answer 12