Clinical and epidemiological variability in severe sepsis: an ecological study.

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.