May 2017

  • How Valid is a Case Fatality Rate (CFR) When Monitoring Cholera Care?

    David A. Sack, MD

    Professor | Johns Hopkins Bloomberg School of Public Health
    Cholera Outbreak in Sierra Leone, Photo: Caroline Thomas, MSF, 2012

    Cholera Outbreak in Sierra Leone, Photo: Caroline Thomas, MSF, 2012

    This post originally appeared on the CORE Group M&E Working Group list serv.

    Many serious diseases report a case fatality rate (CFR) to illustrate the severity of the infection or to monitor the effectiveness of treatment. However, when examining a CFR, one may need to dig a bit deeper to understand how the rate is determined.  As with any rate, the CFR is calculated from a numerator and a denominator.  Generally, the denominator is the number of people with the disease who are diagnosed as having the disease, often counted at the hospital or clinic. The numerator is the number of people, among those who are diagnosed, who die: