Epidemiology
PH 384: Introduction of Epidemiology:
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 pancreatic cancer?
Of people who do not take SUCRALOSE, what is percentage of them had pancreatic cancer?
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
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