Epidemiology

Question 1

What is epidemiology

Answer 1

Research that would look at the the more detailed questions
This would be on a whole population and not just an individual

Question 2

What is incidence

Answer 2

The amount of new people that would have been diagnosed with a disease

Question 3

What is prevalence

Answer 3

The amount of people who would have been diagnosed with the disease and are living with the disease

Question 4

What is a case study

Answer 4

Investigation in an individual or a group

Question 5

What is a case series

Answer 5

A study that would be looking at a group of people who would have the same disease

Question 6

What is an ecological case study

Answer 6

Would look at the association between an exposure and a disease

Question 7

What is a cross sectional study

Answer 7

Would look at the prevalence
Provides a snapshot of the population at a specific time
This would not been good if a disease would have a short duration

Question 8

What is a randomised control study and what are its features

Answer 8

The factors of allocation would be random
Random sampling
Single blind or a Double blind study
Crossover or matching can also be used

Question 9

What is crossover and matching in a RCT

Answer 9

Crossover: group given one medication and then would have it switched later on
Matching: matching patients in the trail based on there certain characteristics

Question 10

What is a case control study

Answer 10

START WITH THE DISEASE
Look backwards and would see if there would be any exposure and then if you can associate this with the disease

Question 11

What are the issues with the case control study’s

Answer 11

Involves retrospective so could lead to recall bias
Hard to establish the time of exposure in relation to the disease
Can’t determine causality

Question 12

What is a cohort study

Answer 12

HAVE THE EXPOSURE AND LOOK TO SEE IF CAUSES THE DISEASE
Need to follow up the patients over a long period of time
Have prospective and retrospective

Question 13

What is a prospective cohort study

Answer 13

Look forward intime
Cohort - exposure- disease

Question 14

What is a retrospective cohort study

Answer 14

Look back in time
Look for the exposure (start with this)
Look back to see if they had previously been diagnosed with the disease (look at the history)

Question 15

What is in the Bradford hill criteria for the causality

Answer 15

Plausible
Consistency
Temporal relationship
Strength
Specificity
Change in the risk factor

Question 16

What is meant by plausiblilty

Answer 16

Do the factors agree with what is already known about the disease

Question 17

What is meant by consistency

Answer 17

Are the results consistent with other groups who have done this study

Question 18

What is meant by a temporal relationship

Answer 18

Did the risk factor appear before the disease developed
If not this may not show cause

Question 19

What is meant by strength

Answer 19

Do those who have been exposed to the risk develop the disease more frequently then the people who have not been exposed

Question 20

What is meant by specificity

Answer 20

Is the risk factor mainly only associated with the disease mentioned or would it connect to many diseased

Question 21

What is meant by change in the risk factor for the criteria

Answer 21

Does the incidence fall or rise when there would be changes in the risk factor

Question 22

What are the types of selection bias

Answer 22

Sampling bias - not representative
Responder bias - only a certain type of people may respond, those who would have time on their hands or those who want a change to be made

Question 23

What are the types of information bias

Answer 23

Follow-up bias - not all people would come to the follow up appointments, this would then mean that some information would be missing
Recording bias - more complete data for some then others

Recall bias - respondents can’t remember details

Social acceptability bias - only answer if they think they won’t be judged or if the factor would be social acceptable (if not would lie)

Interviewer bias - interviewer would right down incorrect information or have their own interpretation

Question 24

What is a confounding factor

Answer 24

Something other then the risk factor in question that could cause the disease

Question 25

How could you deal with confounding factors

Answer 25

Randomisation
Stratified analysis
Matching some of the people in the case

Question 26

What is relative risk

Answer 26

Used when a study is REPRESENTATIVE, so the cohort study
RR = 1 no risk
RR < 1 = decreased risk in developing the disease
RR > 1 = increased risk in developing the disease

Question 27

What is odds ratio

Answer 27

Used when less representative, CASE CONTROL STUDY
OR = 1 = no difference in the odds
OR < 1 = decreased odds
OR > 1 = Increased odds

Question 28

What is ‘number needed to treat’

Answer 28

The number of people that would be needed to be treated for the drug or the intervention to have an effect

Question 29

What is meta analysis

Answer 29

When would take a lot of study’s and compile all the data
This would then give a large study
This would then allow more results

Question 30

What is a systematic review

Answer 30

Using data that would be appraised and summarised
Could also use some that would not be published and then use this to look for correlation

Question 31

What is a mediator

Answer 31

Similar to a confounding factor
Something more natural that would lead to the risk
Sex, age, ethnicity
And less smoking, drinking etc…

Question 32

What is the difference between the cohort and case control study’s

Answer 32

Case control would look at only those who would have the disease
The cohort would look at the exposure and sees if they get the disease
Cohort would also be more representative then the case control study