Blood culture use in the emergency department in patients hospitalized with respiratory symptoms due to a nonpneumonia illness

BACKGROUND: Guidelines and performance measures recommend obtaining blood cultures in selected patients hospitalized with community-acquired pneumonia (CAP). Due to inherent diagnostic uncertainty, there may be spillover effects of these recommendations on other conditions that resemble pneumonia. METHODS: Using data from the 2002 to 2010 National Hospital Ambulatory Medical Care Survey, a nationally representative sample of emergency department (ED) visits in the United States, we analyzed trends in obtaining cultures in patients hospitalized with respiratory symptoms due to a nonpneumonia illness using linear regression. RESULTS: The most common primary admission diagnoses for these visits included heart failure (16%), chronic obstructive pulmonary disease (13%), and chest pain (12%). The proportion of cultures collected in the ED during these visits increased from 10% (95% confidence interval [CI]: 7%-14%) in 2002 to 20% (95% CI: 16%-26%) in 2010 (P<0.001 for the trend). This represented a parallel increase compared to patients hospitalized with CAP (P=0.12 for the difference in trends). CONCLUSIONS: The increase in collecting cultures in the ED in patients hospitalized with respiratory symptoms due to a nonpneumonia illness suggests an important potential unintended consequence of blood culture recommendations for CAP. More attention to the judicious use of blood cultures to reduce harm and costs is needed.