L-Tryptophan and Eosinophilia-Myalgia Syndrome ("EMS")

Edit original node
Author(s)
Leslie Swygert and Richard Dicker
Date published
Jan, 2011
Last updated
21 Jan 2020

Summary

National epidemic of new syndrome in 1989 quickly traced to a commercial product. Case study addresses surveillance, bias, criteria for causation.

Objectives:

  • Discuss issues related to rapid establishment of national surveillance for a newly recognized and little understood disorder
  • Discuss development of case definitions
  • Describe the elements of design and the advantages and disadvantages of case‑control versus cohort studies
  • Discuss some of the biases that might have affected these studies
  • Calculate and interpret a relative risk, odds ratio, and attributable risk percent
  • List and evaluate the criteria for causation