Sepsis Visits and Antibiotic Utilization in U.S. Emergency Departments*

Abstract

To monitor the frequency of sepsis visits in U.S. emergency departments and assess the appropriateness of antibiotic utilization. We analyzed data from the National Hospital Ambulatory Medical Care Survey, defining sepsis as an explicit diagnosis of sepsis via International Classification of Diseases, 9th Revision, Clinical Modification codes 038, 995.91, 995.92, or 785.52. We also monitored trends using cases inferred by infection plus organ dysfunction without explicit diagnosis of sepsis, which we refer to as implicit sepsis cases. We assess changes in visit frequency and ascertain emergency department antibiotic administration rates. Four-stage probability sample of visits to U.S. emergency departments, excluding Federal/military. Adult emergency department visits, United States, 1994-2009. Sepsis was diagnosed explicitly at 260,000 visits per year in U.S. emergency departments (95% CI, 251,000-270,000) or 1.23 visits per 1,000 U.S. population. The visit rate remained stable from 1994 to 2009 (p for trend 0.42). By contrast, the rate of visits with an implicit diagnosis of sepsis increased by 0.07 every 2 years (95% CI, 0.04-0.10; p for trend 0.002). Antibiotics were prescribed in the emergency department during 61% (95% CI, 57-65) of explicit sepsis visits. This increased from 52% in 1994-1997 to 69% in 2006-2009 (difference, 17%; 95% CI, 16.8-17.2). Of antibiotic regimens, 18% covered methicillin-resistant Staphylococcus aureus, 27% Pseudomonas, and 10% extended-spectrum beta-lactamase-producing bacteria, without evidence of targeting according to known risk factors. Of explicit sepsis cases, 31% were admitted to the ICU with 40% mortality (95% CI, 30-51). Overall hospital mortality was 17% (95% CI, 11-22). Explicitly diagnosed sepsis visits did not become more common during 1994-2009. Our data suggest that many emergency department patients with sepsis do not receive antibiotics until they arrive on the inpatient unit. When antibiotics are used among septic emergency department patients, drug-resistant bacteria are covered infrequently. These methods provide a simple approach to tracking the frequency with which sepsis is diagnosed among emergency department patients and to monitoring antibiotic therapy.