Objectives: Asthma is the leading cause of emergency room visits in children, and those with asthma tend to suffer from more severe consequences of respiratory tract infections. The aims of this study were among children who required hospitalization, compare differences between those admitted with or without respiratory infection, describe changes in yearly proportion of asthma among the children admitted with a respiratory infection in New York City from 2006 to 2012 and ascertain how asthma affected the average length of hospital stay for those with respiratory infection.
Methods: We conducted an historical prospective study using data obtained from multiple electronic sources of patients discharged from a 200-bed pediatric hospital in a major metropolitan healthcare system between 2006 and 2012. Patient characteristics were obtained from electronic health records and billing codes.
Results: Among 83,348 patient discharges, there were 5057 (6.1%) with a respiratory infection. In the multivariable model, children with the following characteristics were significantly more likely to be admitted with a respiratory infection as compared with other diagnoses: asthma [odds ratio (OR) 4.68 (95% confidence limits (CL): 4.31, 5.08], male sex [OR:1.11 (1.05, 1.18)], prior hospitalization [OR: 3.65 (3.43, 3.89)], renal failure [(OR: 2.14 (1.70, 2.70)] and Medicaid coverage [OR: 1.93 (1.81, 2.05)]. Children aged ≥ 5 years (OR: 0.44 (0.41, 0.47) and those with diabetes (OR: 0.32 (0.21, 0.51) were less likely to be admitted with a respiratory infection. Hospitalized patients with respiratory infection and asthma, identified by ICD-9 codes, had significantly shorter lengths of stay than patients without asthma, 5.3 and 9.0 days, respectively, p < 0.001. Asthma in patients admitted with a respiratory infection increased from 19.2% in 2006 to 28.2% in 2012, peaking at 34.1% in 2010 (p < 0.001).
Conclusion: This study suggests that asthma is a significant risk factor for hospitalization of children with respiratory infection, and suggests that the prevalence of asthma is increasing over time among children hospitalized with respiratory infection in this urban setting.
Keywords: Acute bronchitis and bronchiolitis; asthma; human metapneumovirus; influenza; pneumonia; respiratory syncytial virus; rhinovirus.