Q1. You are asked to examine the 11 cases of breast cancer found in the last 8 years in the ABC building in Brisbane. This situation was described as follows:...

Q1. You are asked to examine the 11 cases of breast cancer found in the last 8 years in the ABC building in Brisbane. This situation was described as follows:
http://www.smh.com.au/news/National/ABC-investigates-breast-cancer-scare/2005/04/05/1112489489868.html
Some additional information about this situation:
•    10 women fulfilled the case definition (one woman had not invasive breast cancer)
•    Seven cases had worked in the same newsroom.

•    Five were under 40 years of age, 4 were 40-49 years and one older than 50 years.
•    Your investigation of employment records indicates that in that time period 550 women had been employed at ABC Toowong.

•    Their median length of employment was 11 years.
•    The average duration of employment was 3.3 years.
•    Distribution of invasive breast cancer cases according age group at diagnosis and person years at risk is shown in the following table. The age-specific incidence is also provided:
Q2. As epidemiologist, you have identified that smoking prevalence in your country is increasing, particularly in young people. You decide to review the literature to determine what kind of intervention has been found to be the most effective as preventative program.
You collect at least 10 original publications (no reviews) and report your results in no more than three pages (1.5 space, any font but 12 size, normal margins).
Your report need to include the following items: Introduction (to show the rationale of your report); Methods (how the selection of papers was done); Results (what you found. Include at least 2 tables: one to show the general characteristic of the studies, and another showing and comparing the efficacy measures); and Discussion (based on your results need to decide which program you have chosen, and the implications of this selection).
This question is worth 10 marks.


Q3. These questions come from the study (attached) (total 13 marks):
Knuiman, M. Serum Ferritin and Cardiovascular Disease: A 17-Year Follow-up Study in Busselton, Western Australia. Am J Epidemiol 2003; 158:144-149


http://aje.oxfordjournals.org/content/158/2/144.full.pdf+html
a.    How many years were followed up a person who had an incident stroke the 15 of July 1990 and died the 31 of December 1992? (0.5 mark)
b.    How many years were followed up a person that only reported arthritis on the 30 of August 2000? (0.5 mark)
c.    List at least two advantages of using “case-cohort sampling” in this study (1 mark)
d.     “The target population was all adults on the electoral roll (registration to vote is compulsory in Australia) in the Shire of Busselton; the overall response rate for the 1981 survey was 64 percent.”

i.    Identify at least a potential bias, and discuss implications for the internal validity of the study (1 mark).

ii.    Identify at least a potential bias, and discuss implications for the external validity of the study (1 mark).

e.     “A viable blood serum sample was available for about 75 percent of the eligible disease-free cohort.”  List at least two measures the authors did to avoid potential bias because of this (1 mark)
f.    What was the statistical rationale to select a random subset of 450 individuals (1 marks)
g.    If each measurement of ferritin cost UD$10. How much money would be saved in this study, compared to a typical prospective cohort study? (1 mark)
h.    From table 1, discuss the implications for one potential bias (1 mark) and a potential confounding (1 mark)

i.    How did the authors check for the quality of the ferritin values from serum taken in 1981? What limitation to this strategy? (1 mark)
j.    From Figure 1 and Table 2, explain whether gender may statistically interact in the association ferritin-outcome. Why was not tested in the study? (1 mark)
k.    Consider a “nested-case control” study, instead of this “case-cohort’ study. Describe cases and controls in this “nested-case control” study (2 marks)