PASS Cross Sectional Studies

Question 1

Advantages in cross sectional studies

Answer 1

• Inexpensive
• Good for studying prevalence of a condition
• Data no different exposure + outcomes can e collected at one point
• Generating study hypotheses

Question 2

Disadvantages of cross sectional study

Answer 2

Causality cannot be assessed
Findings may be time sensitive
Selection bias
Generalisability
Issues with definition of exposure + outcome

Question 3

Selection bias vs generalisability

Answer 3

Selection bias - findings are incorrect (internal validity)

Generalisability - findings are correct but applying these findings to other situations may be problematic (external validity)

Question 4

What is a cross sectional study?

Answer 4

Exposure and outcome are assessed at same point in time

Exposure and outcome occur before research starts

Question 5

What biases need to be considered in cross sectional studies?

Answer 5

• Selection bias - how representative is the sample of the population?
• Responder bias - who agrees to be in the study? Who stays and who drops out? Is the end sample still representative?
• Measurement bias - how accurate are the measurements?

Question 6

Examples of cross sectional studies

Answer 6

Prevalence study
Seroprevalence study
Genome-wide association study
Environmental health

Question 7

When does research start in a cross sectional study

Answer 7

After exposure + event occurrence

Question 8

How is a cross sectional study conducted?

Answer 8

Data of exposure + event observed at the same time