Figure 6.

Respiratory syncytial virus (RSV) as a proportion of total infant hospitalizations by age (in months) and by admission month, United States infants aged <1 year, National (Nationwide) Inpatient Sample, 2011. Age was available only in 2011. Proportions (%) in each cell were calculated using the total number of infant hospitalizations for chronological age and during each admission month as the denominator. Example interpretation: Of all infants aged 1 month and admitted to the hospital in January, 34.7% were hospitalized due to RSV. RSV was defined by International Classification of Diseases, Ninth and Tenth Revision (ICD-9 and ICD-10) diagnosis codes: RSV (ICD-9: 079.6, 466.11, 480.1; ICD-10: B97.4, J12.1, J20.5, J21.0). Excludes newborn birth hospitalizations (ICD-9: V30.XX–V39.XX; ICD-10: Z38.XX). Sample sizes ≤10 were not reported, in accordance with the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project.