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.