Types of Studies

Question 1

Case Control Study

Answer 1

compares a group of people with disease to a group without disease.
looks for prior exposure or risk factor.
measures the odds ratio.

Question 2

Cohort Study

Answer 2

compares a group with a given exposure or risk factor to a group without such exposure.
Looks to see if exposure increases the likelihood of disease.
measures relative risk.

Question 3

Cross-sectional study

Answer 3

collects data from a group of people to assess frequency of disease at a particular point in time.
Measures disease prevalence.
Can show risk factor association but does not establish causality.

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.

Question 5

Adoption Study

Answer 5

compares siblings raised by biological vs. adoptive parents.

measures heritability and influence of environmental factors

Question 6

Phase I Clinical Trial

Answer 6

study a small number of healthy volunteers.

Assesses safety, toxicity, and pharmacokinetics

Question 7

Phase II Clinical Trial

Answer 7

Study a small number of patients with disease of interest.

Assesses treatment efficacy, optimal dosing and adverse effects

Question 8

Phase III Clinical Trial

Answer 8

Study a large number of patients randomly assigned either to the treatment under investigation or to the best available treatment (or placebo).
Compares the new treatment to the standard of care.

Question 9

Phase IV Clinical Trial

Answer 9

Postmarketing surveillance trial of patients after approval.

Detects rare or long-term adverse effects.