Lesson 4: Descriptive Studies (1) Surveillance, Standardization

Overview Section

Disease surveillance is the basic process by which epidemiologists answer questions about who, where and when.

  • Who is getting the disease? Are there differences in the rates of disease by age? sex? race?
  • Where is the disease happening? Are there geographic areas with particularly high rates? especially low rates?
  • Is the occurrence of the disease changing over time? Is the disease becoming more frequent? less frequent?

Not only can we address important questions for one population, we may also want to compare disease frequency in two populations


Upon completion of this lesson, you should be able to:

  • State at least 5 uses of disease surveillance information.
  • Identify some public sources of disease surveillance data.
  • Recognize situations in which direct or indirect standardization should be considered.
  • Given the required data, standardize a rate with a direct and indirect method.
  • Confidently interpret rate ratios.
  • Evaluate the effectiveness of a disease surveillance system.