Study Designs

Question 1

List our four studies from least to most valid.

Answer 1

1. Cross-sectional
2. Case-control
3. Cohort
4. Clinical Trials

Question 2

Only study that can tell you prevalence of disease?

Answer 2

cross-sectional

Question 3

Potential Bias in Cross-Sectional Studies?

Answer 3

volunteer, recall

Question 4

Benefits of Cross-Sectional Studies

Answer 4

inexpensive, fast, useful for common diseases

Question 5

Potential Bias in Case-Control Studies?

Answer 5

recall bias

Question 6

Two Ways to Use Multiple Controls in Case Control Studies

Answer 6

1. Multiple controls of same type to increase statistical power
2. Controls of different types to help control recall bias

Question 7

Pros of Case Control Studies

Answer 7

less expensive, lots of exposures, great first step, faster, useful for rare diseases

Question 8

Potential Bias in Cohort Studies?

Answer 8

information, loss to follow up, analytic

Question 9

placebo

Answer 9

can only be used if no known therapy exists