Types of observational studies

Question 1

Cross sectional

Answer 1

Collects data from a group of people to assess frequency of disease ( and related risk factors) at a particular point in time.

• Disease prevalence
• Can show risk factor associated with disease BUT cannot show incidence of disease

Question 2

Case-control study

Answer 2

Observational + Retrospective

Compares a group of people with disease to a group without disease.
Looks for prior exposures or risk factor

• Odds Ratio

Question 3

Cohort Study

Answer 3

Observationa + Retrospective/Prospective

Compares a group with a given exposure or risk factor to a group without such exposure
- Looks to see if exposure increase the likelihood of disease.

-Relative risk (RR)

Question 4

Twin Concordance Study

Answer 4

Compares the frequency with which both monozygotic twins or both dizygotic twins develop the same disease

• measures heritability and influence of environmental factors
• nature vs. nurture

Question 5

Adoption studies

Answer 5

Compares siblings raised by biological vs/ adoptive parents:

measures heritability and influence of environmental factors