Epidemiologic Analysis

Question 1

Subjects selected based on exposure (or not)
Usually prospective, but can be retrospective
Examine if different incidence of disease between exposed/not exposed

Answer 1

Cohort Studies

Question 2

Subjects selected based on whether or not they have disorder
Retrospective
Controls should be selected from same population as cases
Examine if exposure is different between cases and control

Answer 2

Case-Control Study Design

Question 3

= 1.0: Need to treat 1 patient to avoid one adverse outcome
= 10: Need to treat 10 patients to avoid one adverse outcome
= 2: We would need to treat 2 patients to prevent one adverse outcome
Smaller number is better

Answer 3

Number Needed to Treat (NNT)

Question 4

Measure of adverse treatment effect
Often relates to complications or side effects
= 1: We need to treat 1 patient to cause an adverse outcome
= 10: We would need to treat 10 patients to cause one adverse outcome
Larger number is better

Answer 4

Number Needed to Harm (NNH)