Benchmarking the Incidence and Mortality of Severe Sepsis in the United States*

TLDR

The first consensus definition of severe sepsis was published in 1992, yet administrative data have yielded widely varying epidemiologic estimates due to inconsistent definitions. The study aims to quantify how four database abstraction methods affect reported incidence and mortality of severe sepsis in the United States. The authors applied four established abstraction algorithms and compared them to ICD‑9 sepsis codes across 2004‑2009 national data. Incidence estimates ranged from 300 to 1,031 per 100,000 and increased ~13% annually, while mortality varied from 14.7% to 29.9% and fell from 35.2% to 12.1% over six years, underscoring the substantial variability driven by abstraction method and the need for a standardized approach.

Abstract

In 1992, the first consensus definition of severe sepsis was published. Subsequent epidemiologic estimates were collected using administrative data, but ongoing discrepancies in the definition of severe sepsis produced large differences in estimates.We seek to describe the variations in incidence and mortality of severe sepsis in the United States using four methods of database abstraction. We hypothesized that different methodologies of capturing cases of severe sepsis would result in disparate estimates of incidence and mortality.Using a nationally representative sample, four previously published methods (Angus et al, Martin et al, Dombrovskiy et al, and Wang et al) were used to gather cases of severe sepsis over a 6-year period (2004-2009). In addition, the use of new International Statistical Classification of Diseases, 9th Edition (ICD-9), sepsis codes was compared with previous methods.Annual national incidence and in-hospital mortality of severe sepsis.The average annual incidence varied by as much as 3.5-fold depending on method used and ranged from 894,013 (300/100,000 population) to 3,110,630 (1,031/100,000) using the methods of Dombrovskiy et al and Wang et al, respectively. Average annual increase in the incidence of severe sepsis was similar (13.0% to 13.3%) across all methods. In-hospital mortality ranged from 14.7% to 29.9% using abstraction methods of Wang et al and Dombrovskiy et al. Using all methods, there was a decrease in in-hospital mortality across the 6-year period (35.2% to 25.6% [Dombrovskiy et al] and 17.8% to 12.1% [Wang et al]). Use of ICD-9 sepsis codes more than doubled over the 6-year period (158,722 - 489,632 [995.92 severe sepsis], 131,719 - 303,615 [785.52 septic shock]).There is substantial variability in incidence and mortality of severe sepsis depending on the method of database abstraction used. A uniform, consistent method is needed for use in national registries to facilitate accurate assessment of clinical interventions and outcome comparisons between hospitals and regions.