Trends in Utilization of Outpatient Respiratory Syncytial Virus Prophylaxis with Palivizumab among Medicaid- and Commercially Insured Infants.

Introduction: Palivizumab is indicated for the prevention of respiratory syncytial virus (RSV) infection in high-risk children. Previous palivizumab utilization studies examined prior authorization claims but did not examine utilization within insured populations as a whole. This study describes outpatient palivizumab utilization trends and characterizes high-risk infants receiving palivizumab within Medicaid- and commercially insured populations.

Methods: Infants born July 1, 2003 through June 30, 2013 were identified in the MarketScan Multistate Medicaid and Commercial claims databases. Infants with ≥ 18 months of continuous medical insurance enrollment with pharmacy benefits after birth and evidence of chronic lung disease of prematurity (CLDP), congenital heart disease (CHD), or preterm birth without CLDP or CHD were studied. Palivizumab use and demographic and clinical characteristics were measured in infant subgroups. Outpatient palivizumab utilization rates were calculated for each seasonal year (July-June) and for each infant subgroup.

Results: In total, 29,350 (2.1%) Medicaid-insured and 9589 (2.5%) commercially insured infants received palivizumab and had CLDP, CHD, or were born at < 37 weeks gestational age (wGA). Infants with CLDP (82%) and those < 29 wGA (78%) had the highest utilization. Decreases in utilization rates between the 2003-2004 and 2012-2013 seasons were seen among Medicaid-insured infants born at 29-36 wGA (all P < .0001), and commercially insured infants born at 31-32 wGA (P < .0001), 33-34 wGA (P = .055), 35-36 wGA (P < .0001), and with CHD (P = .003). Utilization by month was consistent across subgroups among Medicaid- and commercially insured infants, with most doses administered from November to March.

Conclusion: Palivizumab use is targeted to a small percentage of infants who are at highest risk of hospitalization for RSV disease. Utilization declined in recent years in both Medicaid- and commercially insured infant groups. Most palivizumab doses were administered from November to March, with most infants receiving ≤ 5 doses.

Funding: AstraZeneca.