Assignment:
1. Describe the main differences between prevalence and incidence.
For each measure of disease frequency below in questions 2-4, indicate BOTH the type of mathematical parameter and the type of measure of disease frequency:
2. 10% of men have findings of Hepatitis C upon autopsy.
3. There were 6 new cases of melanoma per 100,000 residents in NYC during 2007
4. In a study, 4.3 new cases of cancer per 100,000 person-months were noted.
5. An astute physician diagnoses a 20 year old Caucasian male with an unusual case of a rare cancer usually seen only elderly women of Eastern European descent. She writes up this case and publishes it in the New England Journal of Medicine. This is an example of what type of study?
a. Case Report
b. Case Series
c. Cross-Sectional
d. Correlational
e. None of the above
6. At the beginning of entry to graduate school, students were assessed for level of exercise as well as the presence of cardiovascular disease. This is an example of what type of study?
a. Case Report
b. Case Series
c. Cross-Sectional
d. Correlational
e. None of the above
7. At the beginning of entry to graduate school, students were assessed for level of exercise. Six months later and twelve months later they were evaluated for the presence of cardiovascular disease. This is an example of what type of study?
a. Case Report
b. Case Series
c. Cross-Sectional
d. Correlational
e. None of the above
8. Discuss the advantages and disadvantages of cross sectional studies.
You are conducting a cohort study looking at exposure to chemicals used to make artificial butter flavoring and the risk of developing a rare form of lung cancer.
For your answers to 9-20, show the formula used and your substitutions; state your final answer in sentence form.
In the exposed group, you follow 100 people for the year 2000.
4 were determined to have this form of cancer at the beginning of the study
2 develop this form of cancer on Feb 1
2 develop this form of cancer on Aug 1 and one of these die on Oct 1
7 develop this form of cancer on November 1
5 people (who had never developed disease) were lost to follow-up on June 1
In the unexposed group, you follow 100 people for the year 2000.
2 were determined to have this form of cancer at the beginning of the study
2 develop this form of cancer on July 1.
7 are lost to follow-up on August 1 (not ones with disease)
1 more develops this disease on November 1 and dies on Dec 1
PLEASE NOTE FOR QUESTIONS 9-20, show the formula you are using, the numbers you are substituting into the formula and your final answer in a sentence:
For example:
P (on 2/15)=#existing cases(on2/15)/Total pop (2/15)=8/100=8% The prevalence of ___ on 2/15 is 8% in the ____ group.
9. What is the prevalence of lung cancer in the exposed group on July 15th?
10. What is the prevalence of lung cancer in the exposed group on October 15th?
11. What is the CI of lung cancer in the exposed group during 2000?
12. What is the ID of lung cancer in the exposed group during 2000?
13. What is the case fatality rate of lung cancer in the exposed group during 2000?
14. What is the prevalence of lung cancer in the unexposed group on June 15th?
15. What is the prevalence of lung cancer in the unexposed group on August 15th?
16. What is the CI of lung cancer in the unexposed group during 2000?
17. What is the ID of lung cancer in the unexposed group during 2000?
18. Using ID, calculate the Relative Risk of developing cancer.
19. Using CI, calculate the Risk Difference of developing this form of cancer.
20. Calculate the Population Attributable Risk of developing this form of cancer.