749. Healthcare Utilization After Hospitalization for Respiratory Syncytial Virus or Unspecified Bronchiolitis in the First Year of Life

Abstract

BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of infant hospitalizations, and infants born preterm are at elevated risk. Data on healthcare resource utilization (HRU) and costs after hospitalizations for RSV (RSVH) or unspecified bronchiolitis (UBH) are limited. OBJECTIVE: To quantify HRU and costs across weeks gestational age (wGA) groups 12 months after an RSVH or UBH in the first year of life. METHODS: Infants born 7/1/2009 to 6/30/2015 were identified in the MarketScan Commercial (COM) and Multistate Medicaid (MED) databases and assigned to wGA groups using DRG and ICD codes. Three index hospitalization cohorts were created from inpatient diagnoses in the first year of life: RSVH, UBH without RSVH, or COMP (a comparator without RSVH or UBH). Index dates were randomly assigned to COMP using birth-to-index-admission dates in RSVH. HRU (hospitalizations [HOSP], emergency department visits [ED], outpatient pharmacy fills, other outpatient care) were assessed from 14 days post-index HOSP (or discharge if later) through 12 months post-index HOSP. Propensity score weighting balanced pre-index characteristics (age, sex, region, wGA, birth HOSP characteristics) across cohorts. For each wGA group, models estimated weighted all-cause costs (2016 US$) adjusted for the probability of non-zero costs. RESULTS: Post-index HOSP/ED proportions in RSVH/UBH exceeded COMP (P < 0.05) for combined wGA groups: HOSP: COM, + 5.8%, + 9.3%; MED, + 9.1%, + 12.0; ED: COM, + 15.8%, + 16.2%; MED, + 14.4%, + 17.1%. HOSP (COM and MED) and ED (COM) declined as wGA increased. Other outpatient HRU was greater among RSVH or UBH infants vs. COMP for nearly all COM and MED wGA groups (P < 0.05). MED and COM costs generally increased as wGA decreased. Mean costs in the RSVH/UBH cohorts were lowest in healthy term infants with RSVH (MED $2,018; COM $4,040) and highest in infants < 29 wGA (MED UBH $43,317; COM RSVH $68,838). MED marginal costs (RSVH/UBH less COMP costs) were lowest for term infants (RSVH: $804) and highest for < 29 wGA infants (UBH: $19,896). COM marginal costs, excluding the UBH 29-30 wGA group (n = 45), which had negative marginal costs, were lowest in term infants with RSVH ($1403) and highest in < 29 wGA infants with RSVH ($37,417). CONCLUSIONS: Infants with first-year-of-life RSVH or UBH had greater HRU in the following 12 months vs. nonhospitalized infants. HRU and costs generally increased with decreasing wGA. With one exception, costs were higher in hospitalized infants than comparator infants in all wGA groups.