Clinical and epidemiological variability in severe sepsis: an ecological study

J Epidemiol Community Health. 2018 Aug;72(8):741-745. doi: 10.1136/jech-2018-210501. Epub 2018 Apr 10.


Background: To assess clinical and epidemiological trends of severe sepsis.

Methods: Ecological study of patients presenting to the emergency department with severe sepsis or septic shock between 2005 and 2013. Patients were identified using the state-wide hospital administrative database. Key outcomes included incidence rates (IRs) and mortality rates (per 1000 population) by age and medically underserved areas (MUAs), sepsis case fatality rate (deaths per 100 sepsis cases), and proportions of transfer and comorbidities.

Results: There were 154 019 sepsis cases identified. In 2005, 85+ yo in non-MUAs had a 44% increase in IR compared with those in MUAs, and this difference rose to 74% by 2013. Mortality rates were 1.6 (95% CI 1.3 to 1.8) times greater among 85+ yo in non-MUAs. Mortality rates increased by 1.8% annually, while the sepsis case fatality rate decreased by 7.7%. The proportion of transfer among sepsis cases decreased by 2.1% per year (3.8% in non-MUAs, 0.7% in MUAs).

Conclusions: Sepsis incidence varies geographically, and access to healthcare is one proposed mechanism that may explain heterogeneity. Over time, we may be capturing higher acuity sepsis cases with better recognition and management, as well as observing differential diagnostic coding documentation by location.

Keywords: epidemiology of aging; geography; inequalities; infection; mortality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Databases, Factual
  • Emergency Service, Hospital
  • Humans
  • Incidence
  • Iowa / epidemiology
  • Middle Aged
  • Retrospective Studies
  • Sepsis / epidemiology*
  • Sepsis / mortality
  • Sepsis / physiopathology*