Risk Factors for Severe Bronchiolitis in Australian and Aotearoa New Zealand Infants: A Systematic Review
Kate Loveys1, Meredith L Borland2,3, Ed Oakley4,5,6,7
1Department of Paediatrics: Child and Youth Health, School of Medicine, The University of Auckland, Auckland, New Zealand.
Insights
This systematic review identified key risk factors for severe bronchiolitis in Australasian infants, including younger age, prematurity, and comorbidities. Understanding these factors aids in targeted prevention and respiratory syncytial virus immunisation programs.
Area of Science:
- Pediatrics
- Infectious Diseases
- Public Health
Background:
- Bronchiolitis is a primary cause of infant hospitalizations in Australasia.
- Infants with specific risk factors face increased likelihood of severe disease, prolonged hospitalization, and intensive care unit (ICU) admission.
Purpose of the Study:
- To systematically review and synthesize existing literature on risk factors associated with severe bronchiolitis in infants under 12 months in Australasia.
- To identify factors that may predict severe outcomes and guide preventative strategies.
Main Methods:
- A systematic review of observational studies published from 2000 onwards was conducted.
- Databases searched included MEDLINE, EMBASE, PubMed, Cochrane Library, and CINAHL.
- Risk of bias and evidence quality were assessed using the Newcastle-Ottawa Scale and GRADE, respectively, with narrative synthesis of results.
Main Results:
- Ten studies involving 895,276 infants were included, mostly with low risk of bias.
- Identified risk factors include younger chronological age, prematurity, plural birth, comorbidities (e.g., chronic lung disease, congenital heart disease), Indigenous ethnicity, economic disadvantage, tobacco smoke exposure, and illness onset timing.
- Moderate-quality evidence supports most identified risk factors; evidence gaps exist for factors like breastfeeding and faltering growth, and some international risk factors (e.g., trisomy-21) were not reported in Australasian infants.
Conclusions:
- Risk factors for severe bronchiolitis in Australasian infants largely align with international findings, though some data gaps persist.
- Knowledge of these risk factors is crucial for clinicians assessing infants and for optimizing the delivery of respiratory syncytial virus (RSV) immunisation and other preventive measures.
Aim:
Bronchiolitis is the leading cause of hospital admission in Australasian infants. Infants with risk factors for severe disease may have a greater likelihood of prolonged hospitalisation and intensive care admission. This study aimed to synthesise the literature on risk factors for severe bronchiolitis in Australasian infants.
Methods:
Systematic review including observational studies of risk factors for severe bronchiolitis in Australasian infants (< 12 months), published from 2000. Databases were searched (24 January 2024): MEDLINE, EMBASE, PubMed, Cochrane Library and CINAHL. Risk of bias (RoB) was assessed using the Newcastle-Ottawa Scale for cohort studies, and evidence quality was evaluated using GRADE. Results were narratively synthesised.
Results:
Ten out of 26 467 articles were included (N = 895 276; 12 cohorts, prospective = 5, retrospective = 7). Studies were mostly rated low RoB. There was evidence for the following risk factors: younger chronological age, prematurity, plural birth, comorbidity (chronic lung disease, congenital heart disease, chronic neurological disease, any genetic disorder, any comorbidity), Indigenous ethnicity, economic disadvantage, tobacco smoke exposure and timing of illness onset at presentation. Most risk factors had moderate-quality evidence (range high to very low). Evidence was lacking for the following risk factors present in international literature: breastfeeding exposure and faltering growth. The following risk factors have not been reported in Australasian infants: trisomy-21, congenital diaphragmatic hernia and environmental pollutants.
Conclusions:
Risk factors for severe bronchiolitis in Australasian infants are largely consistent with the international literature, although evidence is lacking for some. Knowledge of these risk factors is highly relevant to those assessing infants with bronchiolitis, and in guiding targeted delivery of respiratory syncytial virus immunisation and other preventative programmes.
Trial Registration:
PROSPERO (CRD42023463917).
More Related Videos
05:31Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels
Published on: August 7, 2017
06:15Protocol and Guidelines for Point-of-Care Lung Ultrasound in Diagnosing Neonatal Pulmonary Diseases Based on International Expert Consensus
Published on: March 6, 2019
Related Concept Videos
01:17Pulmonary Cycle: Exhalation
01:29Asthma-I: Introduction
01:19Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
01:05Breathing
01:26Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
01:20Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.