Key Features of Quantitative Research

Question 1

What type of data is collected and how can it be collected?

Answer 1

(Measureable data)

1) Survey
2) Observation
3) Experiment

Question 2

Prior to carrying out quantitative research, what things need to be collected?

Answer 2

1) Aim
2) Objectives
3) Hypothesis

Question 3

What is an aim?

Answer 3

Broad statement of what will occur in the research

Question 4

What is the objective and what can sometimes be made from the objective?

Answer 4

The aim in more detail and a research question can be dervived from the objective

Question 5

What is a hypothesis?

Answer 5

A statement about the relationship between the variables

Question 6

What are variables?

Answer 6

Characteristics of people or of situations

Question 7

What must quantitative procedures be and why?

Answer 7

Standardised procedures - so that they can be repeated

Question 8

What 2 things must the outcome measure be?

Answer 8

1) Valid - it must measure what it intends to measure

2) Reliable - if it was measured again, under the same conditions, it would give the same results

Question 9

How should the results be presented?

Answer 9

Statistically (e.g. numbers)

Question 10

When analysing the data what 3 things should be focused on?

Answer 10

1) Falsification
2) Establishing casual relationships
3) Establishing the relationship between variables

Question 11

What is falsification?

Answer 11

Hypothesis Testing

Question 12

What does establishing causal relationships mean?

Answer 12

The result of the study must be caused by the effect tested

Question 13

What does establishing the relationship between variables mean?

Answer 13

A statistical relationship between variables must be shown.

Question 14

The Hierarchy of Quantitative Research Designs?

Answer 14

1) Random control trails (RCT’S)
2) Cohort studies
3) Case Control studies
4) Descriptive studies (case series/case reports)
5) Expert Opinion

Question 15

How is a RCT carried out?

Answer 15

Randomly allocate participants into 2 groups and give the intervention to 1 group and then compare

Question 16

Benefits and limitations of RCT’s?

Answer 16

Benefit - simple design

Limitation - Couldn’t be carried out in a healthcare setting due to ethical issues.

Question 17

What are case cohort studies and case control?

Answer 17

Observational studies that do not involve interventions but instead look for the association between 1 entity and another

Question 18

What is the main advantage of cohort studies over case control studies?

Answer 18

Data is collected prospectively (forwardly) which allows for:

1) The data to be collected that you want rather than what is available in a historical context.
2) Allows for data to be collected more accurately

Question 19

What occurs in a cohort study?

Answer 19

Data is collected prospectively (forward)
A group which display risk factors (e.g. smoking) are matched with those that don’t display risk factors (don’t smoke) and then you would see over time who displays a condition (e.g lung cancer)

Question 20

What occurs in a case control study?

Answer 20

Data is collected retrospectively (backwards)

A group who already has the condition (e.g. lung cancer) is matched with those that don’t have the condition

Question 21

If an association is seen between 1 entity and another in case control studies, why is it hard to establish causality between the entities?

Answer 21

As case control studies do not fulfil all of Bradford-Hill’s criteria for causality

Question 22

What is Bradford-Hill’s criteria for causality?

Answer 22

Lists 8 different criterias for causality that must all be fulfilled in order for a causal relationship to be confirmed between 2 entities.

Question 23

The 8 Bradford-Hill’s criteria for causality?

Answer 23

1) Temporal = did the condition occur after being exposed to the risk factor?
2) Strength = The stronger the association between the entities, the more likely the relationships is causal.
3) Dose relationship = If the risk factor exposure increases and the liklihood of the condition increases with it
4) Replication of findings = someone else getting the same results in a different setting
5) Biological Plausibility = do the results fit in with what we already know about biology?
6) Consideration of alternative explanations = Have other possible causes been considered and if so have these been shown to be ruled out?
7) Experiment = Has there been evidence to show that if the risk factor is removed, does it lead to improved health?
8) Coherence with established facts = do the results fit in with past knowledge?

Question 24

What do descriptive studies measure (case reports/case series)?

Answer 24

They measure the progression of a disease. As the sample size of both descriptive studies are small - they only collect Pilot data.
Pilot data will give a general direction of the effects and so will convince researchers that a larger scale study would be worthwhile.

Question 25

Sample size of case reports?

Answer 25

Less than 10 participants

Question 26

Sample size of case series?

Answer 26

More than 10 participants

Question 27

What is the disadvantage of expert opinion and why is it included in the quantitative hierarchy of research designs?

Answer 27

Expert opinion is subjective and so there is a high chance of bias. It is still included in the hierarchy because in some areas of study there has been little quantitative research being carried out and so the only information available is from experts within the area.