Articles
Clinical features for diagnosis of pneumonia in children younger than 5 years: a systematic review and meta-analysis

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Summary

Background

Pneumonia is the biggest cause of deaths in young children in developing countries, but early diagnosis and intervention can effectively reduce mortality. We aimed to assess the diagnostic value of clinical signs and symptoms to identify radiological pneumonia in children younger than 5 years and to review the accuracy of WHO criteria for diagnosis of clinical pneumonia.

Methods

We searched Medline (PubMed), Embase (Ovid), the Cochrane Database of Systematic Reviews, and reference lists of relevant studies, without date restrictions, to identify articles assessing clinical predictors of radiological pneumonia in children. Selection was based on: design (diagnostic accuracy studies), target disease (pneumonia), participants (children aged <5 years), setting (ambulatory or hospital care), index test (clinical features), and reference standard (chest radiography). Quality assessment was based on the 2011 Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. For each index test, we calculated sensitivity and specificity and, when the tests were assessed in four or more studies, calculated pooled estimates with use of bivariate model and hierarchical summary receiver operation characteristics plots for meta-analysis.

Findings

We included 18 articles in our analysis. WHO-approved signs age-related fast breathing (six studies; pooled sensitivity 0·62, 95% CI 0·26–0·89; specificity 0·59, 0·29–0·84) and lower chest wall indrawing (four studies; 0·48, 0·16–0·82; 0·72, 0·47–0·89) showed poor diagnostic performance in the meta-analysis. Features with the highest pooled positive likelihood ratios were respiratory rate higher than 50 breaths per min (1·90, 1·45–2·48), grunting (1·78, 1·10–2·88), chest indrawing (1·76, 0·86–3·58), and nasal flaring (1·75, 1·20–2·56). Features with the lowest pooled negative likelihood ratio were cough (0·30, 0·09–0·96), history of fever (0·53, 0·41–0·69), and respiratory rate higher than 40 breaths per min (0·43, 0·23–0·83).

Interpretation

Not one clinical feature was sufficient to diagnose pneumonia definitively. Combination of clinical features in a decision tree might improve diagnostic performance, but the addition of new point-of-care tests for diagnosis of bacterial pneumonia would help to attain an acceptable level of accuracy.

Funding

Swiss National Science Foundation.

Introduction

In developing countries, pneumonia is the largest cause of deaths in children younger than 5 years.1 Early identification and treatment of patients with pneumonia cases is fundamental to reduce mortality. Identification of which pneumonia cases need antibiotic treatment among the large number of children presenting with respiratory symptoms is a challenge because cough is reported in two thirds of children attending outpatient facilities in low-income countries.2 Chest radiograph, the current gold standard for pneumonia diagnosis,3 is not available in resource-poor settings where the burden of disease is the highest. Even when available, chest radiograph cannot be done for all coughing children because of the very high frequency of this complaint and the potential long-term effects of exposure to x-rays. Therefore, clinical predictors are used to identify children who should receive an antibiotic drug or undergo assessment by chest radiograph.

Since the late 1980s, pneumonia diagnosis in developing countries has relied on the presence of cough, fast breathing, and chest indrawing, as recommended by WHO.4, 5 This recommendation was based on studies published in the late 1980s and validated by other studies in the 1990s. Since then, no major innovation has been made in pneumonia diagnosis and no accurate point-of-care test is available to identify children who would benefit from antibiotics. With the rapid spread of antibiotic resistance worldwide, there is rising concern about overprescription of antibiotics resulting from insufficient specificity of the WHO criteria used to classify acute respiratory infections.6, 7

Here, we assess the diagnostic value of clinical signs and symptoms in identification of children younger than 5 years (excluding infants <2 months) with radiological pneumonia. This evaluation might help to generate more accurate clinical scores from which to make decisions about the necessity of further investigation by chest radiograph or antibiotic treatment for children presenting with respiratory symptoms in low-resource ambulatory care facilities.

Section snippets

Search strategy

We did a systematic literature search in Medline (PubMed), Embase (Ovid), and the Cochrane Database of Systematic Reviews (CDSR), without date or language restrictions. We did our first search on Sept 30, 2013, with an update on Nov 6, 2014. In Medline, we used the following search terms: “pneumonia”[MeSH terms] in combination with: “predictive value of tests”[MeSH terms] OR “sensitivity and specificity”[MeSH terms] OR “reproducibility of results”[MeSH terms] OR “diagnostic test” OR “diagnostic

Results

Our search identified 1839 papers. Through the study selection process (figure 1), 18 articles12, 13, 14, 15, 16, 17, 18, 19 were included in the review and underwent quality assessment using QUADAS-2 (detailed assessment of individual studies is available in the appendix). One of the included articles reported on two separate surveys done in different health facilities in the same country but using the same procedures;15 data were extracted separately and counted as two distinct studies. Table

Discussion

To our knowledge, our Article is the first systematic review with meta-analysis of clinical predictors of pneumonia in children. The comprehensive search, unimpeded by date, country, or language restrictions, allowed the consideration of large amounts of data, compared with previous reviews.7, 30, 34, 35 We considered only data from children aged younger than 5 years, allowing better targeting of the population of interest. Methodological quality was assessed in duplicate and based on a-priori

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