Try to use this articles each with a DIFFERENT study design. (i.e. cross-sectional, case-control, etc.)  Do not use case-control all three times.
answer these questions; 

2 pages

1. What is the study design?
2. Justify why you believe it is the study design you stated in #1 above. Use information you learned in this course to explain the study design.
3. What data set or data source was used? Did the authors collect their own data (primary data collection) or use pre-existing data (secondary data analysis)?

In order to receive full credit, your responses to questions #2 and #3 should be detailed and show that you have read and critically thought through the epidemiological articles you have selected.