Asthma and pneumonia are 2 of the most common reasons children visit the emergency department.1 These conditions have overlapping features and can occur concomitantly. Subsequently, physicians often obtain chest radiographs to diagnose pneumonia in children with asthma, although less than 5% of children have pneumonia that can be radiographically confirmed (hereafter referred to as radiographic pneumonia).2 The consequences of the overuse of radiography include increased time in the hospital, unnecessary radiation exposure, increased costs, and inappropriate antibiotic use due to equivocal imaging findings.3 Given the high rate of normal chest radiographs and the consequences of unnecessary radiographs, more accurate criteria are needed to identify children with asthma who are at increased risk for pneumonia. This study aims to identify risk factors for pneumonia in children with asthma exacerbations.
This is a retrospective cohort study of children 2 to 18 years of age who presented to the emergency department of the Cincinnati Children’s Hospital Medical Center between January 1, 2010, and December 31, 2013, with an asthma exacerbation. Children were identified using a validated algorithm of an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code for asthma (code 493.X) in the first 3 diagnosis positions and receipt of 1 or more doses of albuterol sulfate in the emergency department.4 We excluded children who were younger than 2 years of age to minimize including infants with bronchiolitis. The Cincinnati Children’s Hospital Medical Center institutional review board approved this study. Informed consent was not required because the data were deidentified.
Data were abstracted from the electronic health record (Epic Systems Corporation). Potential factors associated with pneumonia included demographics, medical history, medications, and vital signs (Table 1). The primary outcome was radiographic pneumonia as determined by 2 investigators who manually reviewed the final radiologist reports using a coding manual. Meetings to clarify disagreements occurred weekly. Abnormal radiographs were classified as definite atelectasis, favoring atelectasis, atelectasis vs pneumonia, favoring pneumonia, and definite pneumonia. Radiographic pneumonia was present if the radiologist favored or definitively diagnosed pneumonia.2 Less than 1.9% of data were missing from any variable, so a complete case analysis was performed.
The t test and the χ2 test were performed to examine the relationship between each potential risk factor and radiographic pneumonia. Variables with P ≤ .20 in the univariable analysis were included in a multivariable logistic regression model to determine the association of risk factors with radiographic pneumonia.
There were 14 007 emergency department visits for asthma exacerbation; chest radiography was performed during 4708 of 14 007 emergency department visits (33.6%). Radiographic pneumonia was present in 280 of the 4708 children who underwent chest radiography (5.9%). Factors independently associated with pneumonia included an age of 5 years or older, female sex, fever, and an oxygen saturation of less than 90% (Table 1 and Table 2).
Less than 2% of patients with an asthma exacerbation had radiographic pneumonia, yet one-third underwent chest radiography. Being 5 years of age or older, female, febrile, and/or hypoxic was statistically associated with radiographic pneumonia. A previous study reported that 4.9% of children with wheezing (many <2 years of age) had pneumonia; fever and hypoxia were the strongest pneumonia predictors.2 Our study specifically examines pneumonia in older children with an asthma exacerbation.
Our study is limited by its retrospective nature; however, prior studies found that many of the variables that we did not include (eg, auscultatory findings) were not associated with pneumonia in wheezing children.2 The validated algorithm that we used to identify children may lead to misclassification because we are excluding children with asthma but no active wheezing by requiring albuterol use.4 This will bias our results toward the null because we are underestimating the total burden of asthma, thus likely underestimating the magnitude of effect. In the final models, we only included children who underwent radiography of the chest, which may result in an overestimation of pneumonia. The use of radiographic readings from clinical care may introduce variability and bias, but knowledge of clinical history represents real-world application and does not influence a radiologist’s interpretation.6 Our results suggest that routine use of radiography for younger children with asthma who are not febrile or hypoxic should be discouraged.
Corresponding Author: Todd A. Florin, MD, MSCE, Division of Emergency Medicine, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, ML 2008, Cincinnati, OH 45229 (email@example.com).
Published Online: June 6, 2016. doi:10.1001/jamapediatrics.2016.0310.
Author Contributions: Dr Florin had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Florin, Carron, Ruddy, Ambroggio.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Florin.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Florin, Carron, Huang, Ambroggio.
Obtained funding: Ambroggio.
Administrative, technical, or material support: Ambroggio.
Study supervision: Florin, Shah, Ruddy, Ambroggio.
Conflict of Interest Disclosures: None reported.
Funding/Support: Dr Florin received support from the National Center for Research Resources and the National Center for Advancing Translational Sciences/National Institutes of Health (grant 5KL2TR000078-05). This study was also funded in part by National Institutes of Health grant 1T35HL113229-01 (Ms Carron).
Role of the Funder/Sponsor: The funding agencies played no role in the design and conduct of the study; collection, management, analysis, or interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Disclaimer: Dr Shah is the JAMA Pediatrics Clinical Challenge Editor but was not involved in the editorial review or decision to accept the manuscript for publication.
Additional Contributions: We acknowledge John G. Filcik, BS, for assistance in the review of the radiograph reports and Mona Ho, MS, for statistical assistance. No compensation from a funding sponsor was received by either.
Todd A. Florin, Hannah Carron, Guixia Huang, Samir S. Shah, Richard Ruddy, Lilliam Ambroggio. Pneumonia in Children Presenting to the Emergency Department With an Asthma Exacerbation. JAMA Pediatr. 2016;170(8):803–805. doi:10.1001/jamapediatrics.2016.0310