PUBH 401 Final Exam Questions And All
Correct Answers.
confounder (confounding) - Answer a variable that distorts the true association between
exposure and disease.
1. The variable is a known risk factor for disease
2.The variable is associated with exposure but it isn't a result of the exposure)
How do you design a randomized trial / experiment? - Answer 1. Begin with a defined
population.
2. Randomly assign people to new treatment or current treatment.
3. Follow the subjects in each group through time.
4. At the end of the study compare how many improved with new treatment to how many
improved with current treatment.
5. Can also compare a treatment group to a group with no treatment.
What is a cohort study? - Answer preplanned study following a population over a period of
time
How do you design a cohort study? - Answer 1. Start with group of people by either
2. Record information on exposure status. Gather other relevant information.
3. Follow the group over a defined time period.
4. Assess disease status.
5. Perform data analysis and calculate appropriate measures of risk.
When is it appropriate to use a cohort study design? - Answer 1. When there is good evidence
suggesting an association of a disease with a certain exposure.
2. When you can minimize loss to follow-up (attrition) of the study population.
3. When you can ethically conduct an study
What are the 2 quantitative measures for a cohort study? - Answer 1.Incidence rate in
exposed group = A/ (A+B) x Base
2.Incidence rate in unexposed group= C/ (C+D) x Base
, 2.If incidence in the exposed group < (less than) incidence in the unexposed group, then
NEGATIVE ASSOCIATION
What are the advantages of cohort studies? - Answer 1.You get exposure status before the
occurrence of disease
2.Less Bias
What are the disadvantages of cohort studies? - Answer 1. Expensive
2. Time Consuming
How do you design a case-control study? - Answer 1. Start with a population of interest.
2. Identify a group of people with the disease of interest (cases).
3. Identify a group of people without the disease of interest who will serve as a comparison
group (controls).
4. Gather exposure information and other relevant information.
5. Perform data analysis and calculate appropriate measures of risk.
When should you use a case-control study design? - Answer 1. When searching for a cause of
an adverse health outcome.
2. When the disease being investigated is rare
How can you select cases? - Answer 1. Hospital database
2. Physician practices
3. Clinic patients
4. Registry
How can you select controls? - Answer 1. Non-hospitalized persons living in the community
2. Hospitalized patients admitted for diseases other than the disease of interest
What are the quantitative measures for a case-control study? - Answer 1. Exposed= A/ (A+C)
2. Non-Exposed= B/ (B+D)
Correct Answers.
confounder (confounding) - Answer a variable that distorts the true association between
exposure and disease.
1. The variable is a known risk factor for disease
2.The variable is associated with exposure but it isn't a result of the exposure)
How do you design a randomized trial / experiment? - Answer 1. Begin with a defined
population.
2. Randomly assign people to new treatment or current treatment.
3. Follow the subjects in each group through time.
4. At the end of the study compare how many improved with new treatment to how many
improved with current treatment.
5. Can also compare a treatment group to a group with no treatment.
What is a cohort study? - Answer preplanned study following a population over a period of
time
How do you design a cohort study? - Answer 1. Start with group of people by either
2. Record information on exposure status. Gather other relevant information.
3. Follow the group over a defined time period.
4. Assess disease status.
5. Perform data analysis and calculate appropriate measures of risk.
When is it appropriate to use a cohort study design? - Answer 1. When there is good evidence
suggesting an association of a disease with a certain exposure.
2. When you can minimize loss to follow-up (attrition) of the study population.
3. When you can ethically conduct an study
What are the 2 quantitative measures for a cohort study? - Answer 1.Incidence rate in
exposed group = A/ (A+B) x Base
2.Incidence rate in unexposed group= C/ (C+D) x Base
, 2.If incidence in the exposed group < (less than) incidence in the unexposed group, then
NEGATIVE ASSOCIATION
What are the advantages of cohort studies? - Answer 1.You get exposure status before the
occurrence of disease
2.Less Bias
What are the disadvantages of cohort studies? - Answer 1. Expensive
2. Time Consuming
How do you design a case-control study? - Answer 1. Start with a population of interest.
2. Identify a group of people with the disease of interest (cases).
3. Identify a group of people without the disease of interest who will serve as a comparison
group (controls).
4. Gather exposure information and other relevant information.
5. Perform data analysis and calculate appropriate measures of risk.
When should you use a case-control study design? - Answer 1. When searching for a cause of
an adverse health outcome.
2. When the disease being investigated is rare
How can you select cases? - Answer 1. Hospital database
2. Physician practices
3. Clinic patients
4. Registry
How can you select controls? - Answer 1. Non-hospitalized persons living in the community
2. Hospitalized patients admitted for diseases other than the disease of interest
What are the quantitative measures for a case-control study? - Answer 1. Exposed= A/ (A+C)
2. Non-Exposed= B/ (B+D)
