Basic Epidemiology (32 mins)
Scroll down and read pages 99 to 110 in "Chapter 6: Epidemiology and Prevention: Chronic Noncommunicable Diseases" in order to learn about the application of the four stages of disease prevention.
Click http://apps.who.int/iris/bitstream/handle/10665/43541/9241547073_eng.pdf link to open resource.