Epidemiology Methods
Homework: Case-Control Studies
Type your answers into the word document and be sure to show your work to.
A recent case-control study assessed the relationship of hepatitis C virus (HCV) infection to B-cell non-Hodgkin lymphoma (B-NHL). Cases of B-NHL were identified in the hematology department wards of 10 hospitals located in different cities throughout the United States. The control group consisted of on B-NHL patients admitted to other departments of the same hospitals. (e.g. ophthalmology, general surgery, internal medicine etc). For both cases and controls, only patients with newly diagnosed diseases were included in the study. Testing for HCV was done after cases and controls were hospitalized.
Cases Controls
Age (years) Number HCV Positive Number HCV Positive
<= 55 163 18 231 6
> 55 237 52 165 16
1) What type of case-control study have the authors conducted?
2)Calculate the exposure odds ratio reflecting the HCV/B-NHL association for each group.
3) Describe (in words) the meaning of the OR for the age group >55 yeas.
4) What is an important short coming of the study?
5) You are to conduct a case-control study of people exposed to S. aureus enterotoxin after a foodborne outbreak following a large program function that was catered. Answer each of the questions briefly (2-3 sentences)
a. Design the study
b. What is the control group?
c. What are the strengths and limitations of your deign?
d. How could you improve the design?
e. What are barriers to conducting the study?
f. When considering dissemination, what are some factors to be thoughtful about especially with regard to the study design?
g. When do you present to the public, if you do?
h. What agencies do you think you should partner with in discussing this?
i. Will you match? Why or Why not?