Negative Chest Radiography and Risk of Pneumonia

BACKGROUND AND OBJECTIVES: The ability of the chest radiograph (CXR) to exclude the diagnosis of pneumonia in children is unclear. We sought to determine the negative predictive value of CXR in children with suspected pneumonia. METHODS: Children 3 months to 18 years of age undergoing CXRs for suspected pneumonia in a tertiary-care pediatric emergency department (ED) were prospectively enrolled. Children currently receiving antibiotics and those with underlying chronic medical conditions were excluded. The primary outcome was defined as a physician-ascribed diagnosis of pneumonia independent of radiographic findings. CXR results were classified as positive, equivocal, or negative according to radiologist interpretation. Children with negative CXRs and without a clinical diagnosis of pneumonia were managed for 2 weeks after the ED visit. Children subsequently diagnosed with pneumonia during the follow-up period were considered to have had false-negative CXRs at the ED visit. RESULTS: There were 683 children enrolled during the 2-year study period, with a median age of 3.1 years (interquartile range 1.4-5.9 years). There were 457 children (72.8%) with negative CXRs; 44 of these children (8.9%) were clinically diagnosed with pneumonia, and 42 (9.3%) were given antibiotics for other bacterial syndromes. Of the 411 children with negative CXRs who were managed without antibiotics, 5 were subsequently diagnosed with pneumonia within 2 weeks (negative predictive value of CXR 98.8%; 95% confidence interval 97.0%-99.6%). CONCLUSIONS: A negative CXR excludes pneumonia in the majority of children. Children with negative CXRs and low clinical suspicion for pneumonia can be safely observed without antibiotic therapy.