Reference no: EM132699011
Epidemiology
Problem Set 11
Read the following article: (a direct link to the article is provided in blackboard)
Article - Hart, J. E., Puett, R. C., Rexrode, K. M., Albert, C. M., & Laden, F. (2015). Effect modification of long-term air pollution exposures and the risk of incident cardiovascular disease in us women. Journal of the American Heart Association, 4(12), e002301.
Question 1: Study Design and Methods
a) In your own words, describe the study design used and the enrollment criteria. Could the enrollment criteria result in bias? Why or why not?
b) How was exposure measured? What was the primary issue with exposure data, and how did the authors assess the validity of the exposure data (HINT: check out the statistical analyses section)?
c) What was the primary outcome of interest and how was this measured?
d) The authors included data on potential confounders and effect modifiers. In your own words, what is the difference between a confounder and an effect modifier?
Question 2: Review figure 15.6 in your text, and answer the three questions posed in the figure:
a. Is there an association?
b. If so, is it due to confounding?
c. Is there any association equally strong in strata formed on the basis of a third variable
d. In your own words, interpret what these findings mean using the Hazard Ratios (HRs) for diabetes show in Table 6. NOTE: We haven't covered HR's in this course, so this interpretation does not need to be perfect, but I expect that you will be able to review table 6 and compare the stratum-specific results for women with and without diabetes.