World Library  
Flag as Inappropriate
Email this Article

Case fatality rate

Article Id: WHEBN0003560385
Reproduction Date:

Title: Case fatality rate  
Author: World Heritage Encyclopedia
Language: English
Subject: Ebola virus epidemic in West Africa, 2009 flu pandemic, Baux score, Mortality, 2009–10 flu pandemic in Norway
Collection: Epidemiology, Rates
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Case fatality rate

In epidemiology, a case fatality rate (CFR) — or case fatality risk, case fatality ratio or just fatality rate — is the proportion of deaths within a designated population of "cases" (people with a medical condition), over the course of the disease. A CFR is conventionally expressed as a percentage and represents a measure of risk. CFRs are most often used for diseases with discrete, limited time courses, such as outbreaks of acute infections.

For example: Assume 9 deaths among 100 people in a community all diagnosed with the same disease. This means that among the 100 people formally diagnosed with the disease, 9 died and 91 recovered. The CFR, therefore, would be 9%. If some of the cases have not yet resolved (either died or recovered) at the time of analysis, this could lead to bias in estimating the CFR.

A mortality rate — often confused with a CFR — is a measure of the number of deaths (in general, or due to a specific cause) in a population, scaled to the size of that population, per unit of time. (For example, a rate of 50 deaths per 10,000 population in a year resulting from diabetes. The mortality rate, therefore, would be 50:10,000 or 5:1,000.)

Technically, CFRs are actually risks (or "incidence proportions") and take values between 0 and 1. They are not rates, incidence rates, or ratios (none of which are limited to the range 0-1). If one wants to be very precise, the term "case fatality rate" is incorrect, because the time from disease onset to death is not taken into account. Nevertheless, the term case fatality rate (and the abbreviation "CFR") is often used in the scientific literature.

Contents

  • Examples 1
  • See also 2
  • Notes 3
  • External links 4

Examples

A half dozen examples will suggest the range of possible CFRs for diseases in the real world:

See also

Notes

  1. ^ a b Taubenberger, Jeffery K.; David M. Morens (January 2006). "1918 influenza: the mother of all pandemics". Emerging Infectious Diseases (Coordinating Center for Infectious Diseases, Centers for Disease Control and Prevention) 12 (1): 15–22.  
  2. ^ Li, F C K; B C K Choi; T Sly; A W P Pak (June 2008). "Finding the real case-fatality rate of H5N1 avian influenza". Journal of Epidemiology and Community Health 62 (6): 555–559.  
  3. ^ King, John W (April 2, 2008). "Ebola Virus". eMedicine. WebMd. Retrieved 2008-10-06. 

External links

  • Definitions of case fatality for coronary events in the WHO MONICA Project
  • Swine flu: what do CFR, virulence and mortality rate mean?
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.