Rates of emergency department visits due to pneumonia in the United States, July 2006-June 2009

Abstract

Objectives: Pneumonia hospitalization rates are frequently reported as a measure of pneumonia disease burden in the United States. However, a detailed understanding of pneumonia burden in all health care settings, including the emergency department (ED), is essential for measuring the full effect of this disease on the population and planning and evaluating interventions to reduce pneumonia-related morbidity. The aim of this study was to quantify pneumonia-attributable ED visits in the United States among children and adults during the 3-year period July 2006 through June 2009.

Methods: Rates of pneumonia ED visits were calculated using the Nationwide Emergency Department Sample (NEDS), the largest source of U.S. ED data. Pneumonia ED visits were identified using International Classification of Diseases (ICD) codes within NEDS. A pneumonia ED visit was defined by a primary (first-listed) pneumonia discharge diagnosis or a secondary pneumonia diagnosis with an accompanying primary diagnosis of respiratory failure, shock, septicemia, a sign or symptom consistent with pneumonia, another acute respiratory infection, or an acute exacerbation of a chronic pulmonary disease. Population-based annual rates of pneumonia ED visits stratified by age group and geographic region from July 2006 through June 2009 were calculated. The percentages of pneumonia ED visits resulting in treat-and-release outpatient ED visits were also calculated within each age stratum.

Results: During the study period, 6,917,025 ED visits for pneumonia were identified, representing 2.2% of all U.S. ED visits. During the 3 study years, defined as July through June of 2006-2007, 2007-2008, and 2008-2009, pneumonia ED visit rates per 1,000 person-years were 7.4 (95% confidence interval [CI] = 7.0 to 7.8), 7.8 (95% CI = 7.3 to 8.2), and 7.6 (95% CI = 7.1 to 8.0), respectively. Annual rates were stable over the 3 years within each age group and geographic region. Overall, 39.3% of pneumonia ED visits, including 74.5% of pediatric and 28.1% of adult visits, were managed as treat-and-release outpatient visits.

Conclusions: Pneumonia accounts for 2.2% of ED visits in the United States and results in approximately seven to eight ED visits per 1000 persons per year. A substantial proportion of pneumonia cases diagnosed in the ED are managed in treat-and-release ED outpatient visits, highlighting that enumeration of ED visit rates provides important complementary information to hospitalization rates for the assessment of pneumonia burden.