A Longitudinal Study on Early Hospitalized Airway Infections and Subsequent Childhood Asthma

BACKGROUND Acute airway infections, including bronchiolitis, are common causes of early childhood hospitalization. The development of later asthma may be related to early airway infections in young children. This study is to investigate the relationship between hospitalized airway infections (HAI) in young children (< 3 years old) and later childhood asthma. METHODS Hospitalized children (< 3 years old) with bronchiolitis or other acute airway infections (other HAI group) from 1997-2000 were retrieved from the National Health Insurance Research Database of Taiwan, and compared to age- and gender-matched subjects with regards to asthma until 10 years of age; and potential comorbidities and medical care conditions. RESULTS In total, 3,264 children (1,981 with bronchiolitis; 1,283 with other HAIs) were compared to 18,527 controls. The incidence of childhood asthma was higher in the study (16.2%) than the control (11.7%) group, and most cases were diagnosed between 3-5 years old. The hazard ratios were 1.583 (95% CI: 1.414-1.772) and 1.226 (95% CI: 1.053-1.428) for the bronchiolitis and other HAI subgroups, respectively, compared to the control group, and 1.228 (95% CI: 1.075-1.542) in the bronchiolitis subgroup compared to the other HAIs subgroup. A significantly higher odds ratio (1.973, 95% CI: 1.193-3.263) for the children with congenital heart disease (CHD) in the bronchiolitis subgroup was found at an age of 3-5 years compared to the control group. CONCLUSIONS AND CLINICAL RELEVANCE Young children (< 3 years old) hospitalized due to acute HAIs are at a higher risk of developing childhood asthma at age 3 to 10 years. The parents of children with HAIs at age 0 to 2 years should be informed for the higher risk of developing childhood asthma, especially in children with CHD and bronchiolitis.