Introduction

Question 1

What is the main task of Epidemiology?

Answer 1

To study the distribution, causation and preventability of states of health and disease within different populations

Question 2

What are the primary units of concern in epidemiology? How does this differ from clinical practice?

Answer 2

Groups of people (populations) rather than individuals.
In clinical practice, the main concern is patients whereas in epidemiology, the main concern is both patients and non patients, the populations they both come from and how they differ.

Question 3

What are some common questions that epidemiologists are seeking to answer in their studies?

Answer 3

which type of people are at higher risk?
How does disease frequency change over time?
How does disease frequency change from place to place?

Question 4

How can epidemiological questions be summarised best?

Answer 4

Who, what, when, where and most importantly why.

Question 5

What are the two components of an epidemiological study known as?

Answer 5

1. The risk factor or the exposure

2. The outcome

Question 6

What is the exposure or the risk factor?

Answer 6

A variable associated with increased or decreased incidence of disease.

Question 7

What is the outcome in epidemiology?

Answer 7

Any defined disease or state of health or health related event or death.

Question 8

In terms of the two components of epidemiology, what is the task of the epidemiologist?

Answer 8

To examine whether there is an association between a risk factor and an outcome and to decide whether this relationship is causal.

Question 9

In order to investigate the relationship between the risk factor and the outcome, what do epidemiologists measure?

Answer 9

They measure the strength of association between the association between the risk factor and the outcome

Question 10

why is epidemiology particularly useful in situations which are time sensitive?

Answer 10

Epidemiology can be used to identify the cause of a disease and design prevention strategies even when the biology is not fully understood.

Question 11

Why are biological mechanism understandings not required to develop prevention strategies?

Answer 11

Complete biological mechanism knowledge is not required to implement prevention strategies as if we identify an association between a risk factor and an outcome with confidence, then we can design strategies to reduce the risk factor without needing to know why the risk factor is associated with the outcome.

Question 12

Give an example of why biological mechanism information is not required in order to design a prevention strategy.

Answer 12

We know that we can reduce our risk of developing lung cancer if we do not smoke cigarettes without knowing what is in cigarettes that cause the cancer.

Question 13

What is the epidemiologists role in society?

Answer 13

They make up the foundations of public health, the measure the occurrence of disease within the community and they determine whether there is a need for an intervention.

Question 14

What is the very basic strategy of epidemiological research?

Answer 14

The comparison of different groups of people in terms of their characteristics and health experiences to identify exposure-outcome associations which may reflect the disease causation.

Question 15

What are the names of the two basic approaches to asses whether an exposure is associated with an outcome?

Answer 15

1. Experimental

2. Observational

Question 16

Briefly describe the experimental method of epidemiological research.

Answer 16

Investigators study the impact of varying some factor that they control.

Question 17

Briefly describe the observational method of epidemiological research.

Answer 17

Epidemiologists observe the exposure and disease status of individuals in their studies, they don’t manipulate any variables, but observe and compare incidences to determine associations.

Question 18

Describe an example of a very basic observational study.

Answer 18

Follow up on people who are smokers or non smokers and determine whether their risks of lung cancer are different.

Question 19

What is the major problem with observational studies in epidemiology?

Answer 19

We are comparing the differences between groups in terms of their exposure and their incidence of outcome, however the groups will differ in many other characteristics other than their exposure, and these are called confounding factors.

Question 20

How do confounding factors impact a study?

Answer 20

Makes it more difficult to properly establish a relationship between exposure and outcome of interest.

Question 21

Give a brief example of how a confounding effect affects epidemiological research.

Answer 21

Observed that lung cancer occurs more often in men working in one particular factory. We cannot conclude from this if there is a causal relationship between the workplace and cancer because we do not know if confounding effects mean that the cancer is caused by the fact that all these men working in this factory are more reliant on smoking.

Question 22

How can epidemiologists easily strengthen their confidence in their findings?

Answer 22

The degree of confidence in an epidemiological finding can be strengthened if they are consistent with the findings from other studies conducted in other populations using other study designs.

Question 23

What must happen for epidemiology to be effective on a population level?

Answer 23

Epidemiological findings must be able to influence health policy.

Question 24

In terms of their role within public health, where do epidemiologists tend to disagree?

Answer 24

Some epidemiologists believe that they should be limited to epidemiological research whilst others believe that they should be involved with the application of these findings to public policy and deciding whether or not to implement interventions