Objective: Healthcare use and costs within 1 year of a respiratory syncytial virus lower respiratory tract infection (RSV-LRI) among Medicaid early-preterm and late-preterm infants compared with full-term infants were evaluated.
Methods: Infants born during 2003-2005 were identified from the Thomson Reuters MarketScan Multi-State Medicaid Database. Infants <1 year of age were grouped based on RSV-LRI and unspecified bronchiolitis/pneumonia (UBP) diagnosis codes and stratified by inpatient or outpatient setting. Infants without RSV-LRI/UBP were selected for comparison. Economic and clinical outcomes were analyzed descriptively; the relationship between RSV-LRI/UBP and costs incurred within 1 year of infection were analyzed using logged ordinary least squares models. Results were stratified by gestational age.
Results: Most infants were diagnosed with RSV-LRI/UBP after 90 days of chronologic age. Early-preterm infants had the greatest mean number of inpatient, outpatient, and emergency department visits after an RSV-LRI/UBP episode. The marginal costs among infants with RSV-LRI compared with controls were $34,132 (p < 0.001) and $3869 (p = 0.115) among inpatients and outpatients, respectively. Among late-preterm infants, the marginal costs were $17,465 (p < 0.001) and $2158 (p < 0.001) among inpatients and outpatients, respectively. Full-term infants had the lowest marginal costs (inpatients, $9151 [p < 0.001]; outpatients, $1428 [p < 0.001]). Overall, inpatient infants with RSV-LRI/UBP had higher costs than outpatients, suggesting that increased downstream costs are associated with severity of RSV-LRI/UBP disease.
Limitations: Infants with unknown etiology for bronchiolitis were assigned to the UBP group, which may underestimate the costs of the comparison group.
Conclusions: The burden of RSV-LRI was substantial among early-preterm Medicaid infants. Costs were also higher among late-preterm relative to full-term infants.