Nationwide trends of severe sepsis in the 21st century (2000-2007)

Severe sepsis is common and often fatal. The expanding armamentarium of evidence-based therapies has improved the outcomes of persons with this disease. However, the existing national estimates of the frequency and outcomes of severe sepsis were made before many of the recent therapeutic advances. Therefore, it is important to study the outcomes of this disease in an aging US population with rising comorbidities.

We used the Healthcare Costs and Utilization Project's Nationwide Inpatient Sample (NIS) to estimate the frequency and outcomes of severe sepsis hospitalizations between 2000 and 2007. We identified hospitalizations for severe sepsis using International Classification of Diseases, Ninth Revision, Clinical Modification codes indicating the presence of sepsis and organ system failure. Using weights from NIS, we estimated the number of hospitalizations for severe sepsis in each year. We combined these with census data to determine the number of severe sepsis hospitalizations per 100,000 persons. We used discharge status to identify in-hospital mortality and compared mortality rates in 2000 with those in 2007 after adjusting for demographics, number of organ systems failing, and presence of comorbid conditions.

The number of severe sepsis hospitalizations per 100,000 persons increased from 143 in 2000 to 343 in 2007. The mean number of organ system failures during admission increased from 1.6 to 1.9 (P < .001). The mean length of hospital stay decreased from 17.3 to 14.9 days. The mortality rate decreased from 39% to 27%. However, more admissions ended with discharge to a long-term care facility in 2007 than in 2000 (35% vs 27%, P < .001).

An increasing number of admissions for severe sepsis combined with declining mortality rates contribute to more individuals surviving to hospital discharge. Importantly, this leads to more survivors being discharged to skilled nursing facilities and home with in-home care. Increased attention to this phenomenon is warranted.