A multicenter analysis of the ED diagnosis of pneumonia

The objective of this study was to describe the prevalence of pneumonia-like signs and symptoms in patients admitted from the emergency department (ED) with a diagnosis of community acquired pneumonia (CAP) but subsequently discharged from the hospital with a nonpneumonia diagnosis.

A retrospective, structured, chart review of ED patients with CAP at 3 academic hospitals was performed by trained extractors on all adult patients admitted for CAP. Demographic data, Pneumonia Patient Outcomes Research Team scores, and discharge diagnosis data (International Classification of Diseases, Ninth Revision [ICD-9] codes) were extracted using a predetermined case report form.

A total of 800 patients were admitted from the ED with a diagnosis of CAP from the 3 hospitals, and 219 (27.3%; 95% confidence interval [CI], 24-31) ultimately had a nonpneumonia diagnosis upon discharge. Characteristics of this group included a mean age of 62.6 years, 50% female, and a history of congestive heart failure (CHF) (14%) or cancer (12%). After excluding patients with missing data, 123 patients (65%) had an abnormal chest x-ray, and 13% had abnormal oxygen saturation. Cough, sputum production, fever, tachypnea, or leukocytosis were present in 91.5% of this cohort, and 63.8% had at least 2 of these findings. Twenty alternate ICD-9s were identified, including non-CAP pulmonary disease (18%; 95% CI, 13-24), renal disease (16%; 95% CI, 13-19), other infections (9%; 95% CI, 7-11), cardiovascular diseases (3%; 95% CI, 2-4), and other miscellaneous diagnosis (28%; 95% CI, 25-31).

Our data suggest that the ED diagnosis of CAP frequently differs from the discharge diagnosis. This may be due to the fact that a diagnosis of CAP relies on a combination of potentially nonspecific clinical and radiographic features. New diagnostic approaches and tools with better specificity are needed to improve ED diagnosis of CAP.