Total healthcare costs in the US for preterm infants with respiratory syncytial virus lower respiratory infection in the first year of life requiring medical attention

Background: Respiratory syncytial virus (RSV) lower respiratory infection (LRI) is the most common cause of hospitalization among infants 51 year of age. The healthcare costs of preterm infants with RSV LRI were compared with those without RSV LRI in the first year of life. Methods: This retrospective cohort study propensity-matched premature infants <= 36 weeks' gestational age (wGA) and/or <= 2499 g birth weight, born May 1, 2001 through April 30, 2006 (five RSV seasons) with RSV LRI to those without RSV LRI in a national United States health plan. The primary outcome was first-year healthcare costs and utilization excluding the birth hospitalization compared between the study cohorts. Subgroup analysis evaluated costs and healthcare resource utilization by GA (<= 32 wGA and 33-36 wGA) and hospitalization status (hospitalized and outpatient). Results: A total of 2995 infants with RSV LRI were matched to 2995 controls. Infants with RSV LRI had $9115 higher healthcare costs (RSV LRI group: $19 559; control group: $10 444; p < 0.001) in the first year of life. Late preterm infants (33-36 wGA) with an RSV hospitalization incurred $21 977 higher costs (p < 0.001) and those with an outpatient RSV LRI incurred $3898 higher costs (p < 0.001) compared to corresponding controls. Similar results were found among infants <= 32 wGA with higher costs in the RSV LRI group. Rates of all-cause hospitalizations, emergency department visits, and ambulatory visits were significantly higher among infants with RSV LRI compared to controls. Conclusion: Development of RSV LRI among preterm and late preterm infants is associated with significantly higher healthcare costs in the first year of life. These findings must be considered in the context of potential study limitations that may have over-or underestimated costs, such as unconfirmed RSV infection, unintentional omission of fatal cases, and unobserved imbalances between groups.