Prevalence and predictors of radiographic pneumonia in children with wheeze: A systematic review and meta-analysis.

Background: Diagnostic uncertainty exists surrounding the identification of radiographic pneumonia in children with wheeze. It is important to determine the prevalence and clinical predictors of pneumonia in this population to limit chest radiography (CXR) and promote judicious antibiotic use.

Objectives: The objectives were to (1) estimate the prevalence of radiographic pneumonia in children with wheeze and (2) systematically review the diagnostic accuracy of clinical findings for the identification of radiographic pneumonia.

Methods: Data sources were MEDLINE, PubMed Central, Cochrane Library, CINAHL, and Web of Science (January 1995 to September 2023). For study selection, two reviewers identified high-quality studies reporting on clinical characteristics associated with radiographic pneumonia in wheezing children (age 0-21 years). Using Covidence software, data regarding study characteristics, methodologic quality, and results were extracted. Data were pooled using random-effects meta-analysis.

Results: A total of 8333 unique titles and abstracts were reviewed. Twelve studies, representing 7398 patients, were included. Fifteen percent of children with wheeze undergoing CXR had pneumonia. Findings associated with radiographic pneumonia included temperature ≥ 38.4°C (positive likelihood ratio [LR+] 2.1, 95% CI 1.2-3.6, specificity 85%), oxygen saturation < 92% (LR+ 3.6, 95% CI 1.4-8.9, specificity 89%), and grunting (LR+ 2.7, 95% CI 1.6-4.4, pooled specificity 91%). Factors associated with the absence of radiographic pneumonia included lack of fever (negative likelihood ratio [LR-] 0.67, 95% CI 0.52-0.85) and oxygen saturation ≥ 95% (LR- 0.64, 95% CI 0.42-0.98). Tachypnea and auscultatory findings were not associated with radiographic pneumonia.

Discussion: Heterogeneity across studies limits generalizability. Additionally, all included studies overestimate the rate of radiographic pneumonia given the fact that all subjects had a CXR performed due to clinical suspicion of pneumonia.

Conclusions: Radiographic pneumonia occurs in 15% of wheezing children undergoing CXR for pneumonia. Auscultatory findings and tachypnea do not differentiate children with and without pneumonia, and the rate of radiographic pneumonia is very low in the absence of fever and hypoxemia.