CHEST Guidelines-Pneumonia-in-Infancy-and-Risk-for-Asthma_2021

Pneumonia-in-Infancy-and-Risk-for-Asthma_2021_ches

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The study explores the link between pneumonia in infancy and the risk of developing asthma by age 4, alongside examining familial confounding and the influence of pneumococcal vaccination. Researchers conducted a nationwide cohort analysis of 900,000 Swedish children, utilizing a family design approach to control for shared environmental and genetic factors.<br /><br />Key findings indicated a strong association, with those having pneumonia in infancy presenting over three times the risk of asthma at age 4. The data showed adjusted odds ratios (OR) of 3.38 and 2.81 in general and sibling analyses, respectively. There was a notable effect from nationwide pneumococcal conjugate vaccine (PCV) implementation, resulting in an increased relative risk of asthma in the PCV era, possibly due to a heightened proportion of viral pneumonia cases.<br /><br />The study highlights that residual familial confounding and familial environment influenced the association, as evidenced by slightly attenuated ORs in the sibling analyses. However, the analysis suggests, though does not confirm, a causal relationship between early pneumonia and the subsequent risk of asthma, which was stronger among viral pneumonia cases post-PCV introduction.<br /><br />The study acknowledges the complexity of asthma diagnosis and confounding factors such as reverse causation, where respiratory issues may predate pneumonia or result jointly from environmental and genetic predispositions. The authors call for future investigation into the long-term asthma risk post-pneumonia in infancy, the benefit of pneumonia preventive measures, and studies involving low-income countries, where data is limited but the impact could be significant.<br /><br />Overall, the findings emphasize potential implications on public health strategies around managing childhood pneumonia and asthma risk, considering genetic, environmental, and vaccination status. The study suggests that interventions focusing on reducing pneumonia incidence could also offer additional benefits in preventing childhood asthma development.

Keywords

pneumonia

asthma

infancy

familial confounding

pneumococcal vaccination

cohort analysis

genetic factors

public health

childhood asthma

environmental factors