Reference no: EM132268871
Assignment
1. Here is an example of case-control study. You want to do a study to see if SUCRALOSE (artificial sugar) is a risk factor for pancreatic cancer. You assemble a sample of 1000 pancreatic cancer cases from a cancer registry and 1000 controls (people without the disease) using random digit dialing. Of the cases, 500 did not use SUCRALOSE; Of the controls, 800 did not use SUCRALOSE.
Questions:
1) Construct contingency table.
2) Answer the following questions:
Of people who had SUCRALOSE, what is percentage of them had pancreaticcancer?
Of people who do not take SUCRALOSE, what is percentage of them had pancreaticcancer?
3) Calculate odds ratio
4) Interpret odds ratio
2. In 2005, an investigator drew a random 1000 sample of all adults without a chronic disease in a community. At this time point, forty (40%) percent of people without the disease had a particular exposure, which is fixed.
Within the next five years, 55 cases of the disease occurred in the study population, and 40 of these cases were exposed. Assume steady state conditions and that the exposure is not a prognostic factor for the disease.
Questions:
5) Construct contingency table.
6) Estimate relative risk of exposure
7) Interpret relative risk of exposure
8) Estimate the attributable risk to exposure
9) Estimate the population risk difference
• Section 1. Short answer question.
1. Define the term descriptive epidemiology and take a specific example to discuss some of its use.
2. Define the term ecologic study design. Name and describe one advantage and one disadvantage of ecologic studies.
3. List four major characteristics of epidemiologic study designs and state in which ways that case control, cross-section study designs differ from one another.
• Section 2. Study design questions.
1-A case-control study was conducted among male veterans under age 60 to evaluate the association smoking, and oral cancer (Rothman & Keller, 1972). Smoking status was the primary exposure variable.
|
Smoker
|
Cases
|
Controls
|
Total
|
|
Yes
|
233
|
184
|
417
|
|
No
|
9
|
32
|
41
|
|
Total
|
242
|
216
|
458
|
a. Calculate percentage of smoker in cases
b. Calculate percentage of smoker in controls.
c. Compare the two percentage, and summarize your finding based on the comparison.
d. Calculate the odds ratio and provide brief interpretation about the odds ratio.
2- Suppose you do a study to see if benzene exposure causes leukemia. You match the 1970 employment records of Benzene, Inc. (a Kentucky company) for 3000 workers to the Kentucky Cancer Registry.
You use the employment records of 3000 UK workers as a comparison group. Of the workers at Benzene, Inc., 145 develop leukemia over a 30-year period compared to 10 from UK workers.
a. What kind of study is this?
b. Construct the contingency table
c. Calculating the risk of Leukemia for works exposing to Benzene.
d. Calculating the risk of Leukemia for works not exposing to Benzene.
e. What is the relative risk (RR) of exposing to Benzene and provide brief interpretation about the relative risk?