Week 3

Question 1

What do experimental investigations involve?

Answer 1

Involve an intervention (treatment), generating quantitative data and testing hypotheses.

Question 2

By what methods can data be collected for observational studies?

Answer 2

In these studies, data can be collected using qualitative and quantitative methods.

Question 3

What is a cross-sectional study?

Answer 3

A type of observational study involving the analysis of data collected from a population at a specific point in time where the investigator has no control over the exposure of interest.

Question 4

What is the aim of a cross-sectional study?

Answer 4

• Aim to provide data on the entire population under study.

Question 5

When is a cross-sectional study likely to be used?

Answer 5

• The purpose of the study is descriptive, often in the form of a survey.
• Usually there is no hypothesis as such, but the aim is to describe a population with respect to an outcome and a set of risk factors.
• The purpose of the study is to find the prevalence of the outcome of interest, for the population at a given timepoint. – Provides a ‘snapshot’ of the outcome and the characteristics associated with it, at a specific point in time.
• To investigate associations between risk factors and the outcome of interest

Question 6

What does a cross-sectional study involve?

Answer 6

– Identifying a defined population at a particular point in time
– Measuring a range of variables on an individual basis
– At the same time measuring outcome of interest
– They are carried out at one time point or over a short period

Question 7

When may a study including only individuals with a specific characteristic be used for?

Answer 7

These are often used to assess the prevalence of acute or chronic conditions, or to answer questions about the causes of disease or the results of intervention at a defined time (suvery or census).

Question 8

What is a cohort study?

Answer 8

Any group of people who are linked in some way and followed over time.

Question 9

How does a cohort study work?

Answer 9

• Two groups of people followed over time
• One group has received an intervention or exposure
• Groups otherwise closely matched
• Groups followed over time

Question 10

What are cohort studies used for?

Answer 10

• Can be used for causation, diagnostic, risk and therapeutic studies

Question 11

What is a case-control study?

Answer 11

“Case” is someone with a condition matched with a “control” who doesn’t have the condition.

Question 12

Explain how a case-control study works

Answer 12

• Case-control studies used mainly for causation studies
• Patient with outcome matched to control
• Investigations made into possible causes in both patients
• May be only option in rare conditions
• Here researchers use existing records to identify people with a certain health problem (“cases”) and a similar group without the problem (“controls”).

Question 13

Are randomised control trials quantitative or qualitative ?

Answer 13

Quantitative