Cumulative incidence of post‐infection asthma or wheezing among young children clinically diagnosed with respiratory syncytial virus infection in the United States: A retrospective database analysis

BACKGROUND: Respiratory syncytial virus (RSV) infection is implicated in subsequent development of asthma/wheezing (AW) among term and pre‐term infants. We describe the cumulative incidence of AW among hospitalized and ambulatory neonates/infants/toddlers following RSV infection diagnosis over three independent follow‐up periods. METHODS: Between January 1, 2007 and March 31, 2016, patients aged 0‐2 years old with first clinical diagnosis of RSV infection were identified using the Optum(®) integrated electronic health records and claims database. Patients diagnosed with AW ≤ 30 days post‐RSV diagnosis were excluded. Three cohorts with 1, 3, and 5 years of follow‐up were stratified by presence or absence of specific RSV high‐risk factors, including pre‐term birth and pre‐defined, pre‐existing comorbidities. Descriptive statistics and logistic regression results were reported. RESULTS: Overall, 9811, 4524, and 1788 RSV‐infected high‐risk factor negative patients were included in 1, 3, and 5‐year independent cohorts, respectively. Of these, 6.5%, 6.9%, and 5.8%, respectively had RSV‐related hospitalization. By the end of follow‐up, 14.9%, 28.2%, and 36.3% had AW events. Overall, 3030, 1378, and 552 RSV‐infected high‐risk factor positive patients were included in the respective cohorts. Of these, 11.4%, 11.1%, and 11.6%, respectively were hospitalized with initial RSV infection and 18.1%, 32.9%, and 37.9% had subsequent AW events within the follow‐up period. Logistic regression confirmed RSV‐related hospitalization significantly increased the likelihood of developing AW (P < .05) in high‐risk factor positive and negative patients. CONCLUSIONS: In infants diagnosed with RSV infection, RSV‐related hospitalization was associated with a significantly increased likelihood of AW development for at least 5 years, compared with non‐hospitalized patients.