Background: The risks of long term sequelae from childhood pneumonia have not been systematically assessed. The aims of this study were to: (i) estimate the risks of respiratory sequelae after pneumonia in children under five years; (ii) estimate the distribution of the different types of respiratory sequelae; and (iii) compare sequelae risk by hospitalisation status and pathogen.
Methods: We systematically reviewed published papers from 1970 to 2011. Standard global burden of disease categories (restrictive lung disease, obstructive lung disease, bronchiectasis) were labelled as major sequelae. 'Minor' sequelae (chronic bronchitis, asthma, other abnormal pulmonary function, other respiratory disease), and multiple impairments were also included. Thirteen papers were selected for inclusion. Synthesis was by random effects meta-analysis and meta-regression.
Results: Risk of at least one major sequelae was 5.5% (95% confidence interval [95% CI] 2.8-8.3%) in non hospitalised children and 13.6% [6.2-21.1%]) in hospitalised children. Adenovirus pneumonia was associated with the highest sequelae risk (54.8% [39.2-70.5%]) but children hospitalised with no pathogen isolated also had high risk (17.6% [10.9-24.3%]). The most common type of major sequela was restrictive lung disease (5.4% [2.5-10.2%]) . Potential confounders such as loss to follow up and median age at infection were not associated with sequelae risk in the final models.
Conclusions: All children with pneumonia diagnosed by a health professional should be considered at risk of long term sequelae. Evaluation of childhood pneumonia interventions should include potential impact on long term respiratory sequelae.