Altitude and environmental climate effects on bronchiolitis severity among children presenting to the emergency department.

Bronchiolitis, a respiratory illness, is the leading cause of hospitalization for infants. The authors examined whether environmental factors contributed to the severity of the bronchiolitis illness. They compiled environmental data (temperature, dew point, wind speed, precipitation, altitude, and barometric pressure) to augment clinical data from a 30-center prospective cohort study of emergency department patients with bronchiolitis. They analyzed these data using multivariable logistic regression. Higher altitude was modestly associated with increased retractions (odds ratio [OR] = 1.6; 95% confidence interval [CI] = 1.1-2.1; p < .001) and decreased air entry (OR = 2.0; 95% CI = 1.6-2.6; p < .001). Increasing wind speed had a minor association with more severe retractions (OR = 1.3; 95% CI = 1.1-1.7; p = .02). Higher dew points had a minor association with lower admission rates (OR = 0.9; 95% CI = 0.8-0.996; p = .04). Altitude and environmental climate variables appear to have modest associations with the severity of bronchiolitis in the emergency department. Further studies need to be conducted, however, on limiting exposure to these environmental variables or increasing humidity before making broad recommendations.