Background: The World Health Organization (WHO) established guidelines that rely on simple clinical signs for the diagnosis of childhood pneumonia in resource-limited settings. Our objective was to evaluate the test characteristics of the WHO criteria for the diagnosis of radiographic pneumonia in the emergency department setting.
Methods: We prospectively collected clinical information from children ≤5 years of age presenting to a US-based pediatric emergency department who had a chest radiograph performed for suspicion of pneumonia. Patients were classified as meeting the WHO case definition of pneumonia if they had both 1) cough or difficulty breathing and 2) age-specific WHO-defined tachypnea. The primary outcome was radiographic pneumonia based on the final radiology report. Among children with cough or with difficulty breathing, receiver operator characteristic curve analysis was used to evaluate the test characteristics of triage respiratory rate, temperature and oxygen saturation for the diagnosis of radiographic pneumonia.
Results: Two thousand eight children were enrolled. Median age was 19 months, and 28.5% had tachypnea based upon age-specific respiratory rate thresholds. Of the 324 children with radiographic pneumonia, 111 met the WHO case definition of pneumonia (sensitivity = 34.3%, 95% confidence interval: 29.1-39.7). Triage respiratory rate demonstrated an area under the curve of 0.54 for the diagnosis of radiographic pneumonia. The area under the curve for triage temperature and oxygen saturation was 0.56 and 0.60, respectively.
Conclusions: The WHO criteria demonstrated poor sensitivity for the diagnosis of radiographic pneumonia in a US-based pediatric emergency department. Compared with respiratory rate, oxygen saturation offered slightly improved test characteristics. Although applied to a different target population, these findings suggest the WHO criteria may not be a sensitive screening tool for the diagnosis of pneumonia in children.