Epidemiology of Hospital-Onset Versus Community-Onset Sepsis in U.S. Hospitals and Association With Mortality: A Retrospective Analysis Using Electronic Clinical Data

Abstract

Objectives: Prior studies have reported that hospital-onset sepsis is associated with higher mortality rates than community-onset sepsis. Most studies, however, have used inconsistent case-finding methods and applied limited risk-adjustment for potential confounders. We used consistent sepsis criteria and detailed electronic clinical data to elucidate the epidemiology and mortality associated with hospital-onset sepsis.

Design: Retrospective cohort study.

Setting: 136 U.S. hospitals in the Cerner HealthFacts dataset.

Patients: Adults hospitalized in 2009-2015.

Interventions: None.

Measurements and main results: We identified sepsis using Centers for Disease Control and Prevention Adult Sepsis Event criteria and estimated the risk of in-hospital death for hospital-onset sepsis versus community-onset sepsis using logistic regression models. In patients admitted without community-onset sepsis, we estimated risk of death associated with hospital-onset sepsis using Cox regression models with sepsis as a time-varying covariate. Models were adjusted for baseline characteristics and severity of illness. Among 2.2 million hospitalizations, there were 95,154 sepsis cases: 83,620 (87.9%) community-onset sepsis and 11,534 (12.1%) hospital-onset sepsis (0.5% of hospitalized cohort). Compared to community-onset sepsis, hospital-onset sepsis patients were younger (median 66 vs 68 yr) but had more comorbidities (median Elixhauser score 14 vs 11), higher Sequential Organ Failure Assessment scores (median 4 vs 3), higher ICU admission rates (61% vs 44%), longer hospital length of stay (median 19 vs 8 d), and higher in-hospital mortality (33% vs 17%) (p < 0.001 for all comparisons). On multivariate analysis, hospital-onset sepsis was associated with higher mortality versus community-onset sepsis (odds ratio, 2.1; 95% CI, 2.0-2.2) and patients admitted without sepsis (hazard ratio, 3.0; 95% CI, 2.9-3.2).

Conclusions: Hospital-onset sepsis complicated one in 200 hospitalizations and accounted for one in eight sepsis cases, with one in three patients dying in-hospital. Hospital-onset sepsis preferentially afflicted ill patients but even after risk-adjustment, they were twice as likely to die as community-onset sepsis patients; in patients admitted without sepsis, hospital-onset sepsis tripled the risk of death. Hospital-onset sepsis is an important target for surveillance, prevention, and quality improvement initiatives.

Figure 1.

Study cohort derivation from Cerner HealthFacts dataset

Figure 2.. Comparison of major clinical characteristics in patients with hospital-onset sepsis, community-onset sepsis, and no sepsis.

A, Infectious diagnoses and syndromes in patients with hospital-onset vs community-onset sepsis vs no sepsis. All categories were identified by ICD-9-CM discharge diagnosis codes, except for positive blood cultures (obtained by microbiology data). B, Dysfunctional organs (by Centers for Disease Control and Prevention Adult Sepsis Event Criteria) at sepsis onset.