The Changing Epidemiology and Definitions of Sepsis

Abstract

This article describes the trends in the incidence of and mortality from sepsis in the United States and globally. The article then discusses the known factors associated with increased risk for developing sepsis and the limitations of the current clinical definition and the clinical correlations of the current epidemiology.

Keywords: Epidemiology; Sepsis; Septic shock; Severe sepsis.

Figure 1. Abbreviated Timeline of the Conceptual Definition of Sepsis

Figure 2. Comparison of Epidemiological Trends of Severe Sepsis in the United States Between Three Case Definitions

From Gaieski DF, Edwards JM, Kallan MJ, et al. Benchmarking the incidence and mortality of severe sepsis in the United States. Critical care medicine 2013;41(5):1167–74; with permission.

Figure 3. Crude Mortality from Lower Respiratory Tract Infections by World Health Organization Region and World Bank Income Group

Data from World Health Organization. Global Health Data Repository: Death Rates [August 12, 2015]. Available from: http://apps.who.int/gho/data/node.main.CODRATE?lang=en.

Figure 4. Average Annual Age-Adjusted Incidence of Sepsis-Related Mortality per 100,000 over 1999–2013 by State in the United States

Data pulled from Centers for Disease Control and Prevention, National Center for Health Statistics. Multiple Cause of Death 1999–2013 on CDC WONDER Online Database, released 2015. Data are from the Multiple Cause of Death Files, 1999–2013, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program. Accessed at http://wonder.cdc.gov/mcd-icd10.html on Aug 27, 2015 7:00:28 PM

Figure 5. Total Sample Size Required to Show a Relative Risk Difference of 10% Based on Mortality From Control Arms of Randomized Controlled Trials of Severe Sepsis and Septic Shock

The y-axis corresponds to the years of publication of respective randomized control trials. The left-side y-axis corresponds to the reported case-fatality of the control arms of trials enrolling patients with severe sepsis or septic shock; with dots representing individual trials and the blue line representing a simple unweighted linear regression of case-fatality by year. The right-side y-axis represents the total sample size (both experimental and control arms) that would be required to show a relative mortality risk difference of 10% with a power of 90% at an alpha of 0.05 for a hypothetical experimental trial with the control arm’s mortality rate estimated from the aforementioned regression of that given year. The red line is a simple plot of this total sample size calculated from the control arm’s mortality estimated from the blue regression line for each year. Data from supplement of Stevenson EK, Rubenstein AR, Radin GT, Wiener RS, Walkey AJ. Two decades of mortality trends among patients with severe sepsis: a comparative meta-analysis*. Critical care medicine. 2014;42(3):625–31.