Skip navigation and go directly to content.
Agency for Toxic Substances and Disease Registry Search  |  Index  |  Home  |  Glossary  |  Contact Us  
 module banner.  
  Previous PageMain MenuPHA HomeFeedbackNext Page

PHA home.
Health Data
Conclusions
Help




Step 2. Characterizing the Limitations of Health Data

bullet Epidemiologic Studies

The ability of an epidemiologic study to detect an increased incidence of disease is dependent on the increased risk level and on the size of the affected population. For example, if an estimated exposure results in an increased cancer incidence of 1 in 10,000 over background (a high risk level), it would not be detectable in a study population of several thousand people (a very large cohort.)

Additional epidemiologic study limitations might include

bullet

exposure variability over time (past and present) and populations

bullet

latency periods between exposure and health outcome (cancer, for example)

bullet

confounding factors (such as smoking or alcohol use)

bullet

different measurement points for exposure (for example, average or lifetime)

bullet

incomplete or inaccurate monitoring systems

bullet

small study size

bullet

people moving into and out of the study area

 
< Previous | Next >


spacer Last updated: May 30, 2007 bullet ATSDR EPH Training Coordinator
spacer
DHAC Home


spacer
  ATSDR Home  |  Search  |  Index  |  Contact Us
About ATSDR  |  News Archive  |  ToxFAQs  |  Public Health Assessments
Privacy Policy  |  External Links Disclaimer |  Accessibility
U.S. Department of Health and Human Services