Epidemiology 2

These questions refer to the paper by Velicer, C. M., et al. (2004). “Antibiotic use in relation to the risk of breast cancer.” Jama 291 (7): 827-35.

Question 1

a)      What was the aim of this study?  (1 mark)

b)      Provide one reason why a case-control design was suitable for this study.   (1 mark)

c)   Provide one limitation of using a case-control design in this study? (1 mark)

Question 2

a)      How were the cases defined?  (2 marks)

b)      Explain how the cases were selected      (2 marks)

c)      Explain how the controls were selected  (2 marks)

d)     Define the meaning of  “frequency matching” (2 marks)

e)      What is the purpose of “frequency matching”? (1 mark)

f)       Identify the reference population from which the study population was obtained (2 marks)

g)      Describe 2 potential selection biases that might be relevant to the selection of the study population from the reference population.  (2 marks)

h)      Discuss what consequences of these potential selection bias (from previous question) (2 marks)

Question 3

a)      Describe in detail how the main exposure of this study was measured? (2 marks)

b)      Identify 3 errors and/or biases that might have occurred during the measurement of exposure? (3 marks)

c)      List two actions the authors did to reduce error or bias in the measurement of exposure (2 marks)

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