Prevalence of respiratory syncytial virus (RSV) risk factors and cost implications of immunoprophylaxis to infants 32 to 35 weeks gestation for health plans in the United States.

Background: During the period of this study, the American Academy of Pediatrics (AAP) 2006 guidelines recommended respiratory syncytial virus (RSV) prophylaxis for infants 32 to 35 weeks gestation age (wGA) with two or more of five risk factors (RFs). New recommendations have recently been published in 2009. The cost implications of expanding this list of RFs to include other evidence-based RFs like passive smoke exposure (PSE), crowded living conditions (CLCs), and young chronological age (YCA) are unclear.
Methods: We estimated the prevalence of RSV RFs in a US sample of infants 32 to 35 wGA referred for prophylaxis from nine specialty pharmacy providers during the 2007-2008 season. We estimated the percent eligible for RSV prophylaxis under various potential RF coverage policies. Using a budget impact model, we calculated the per-member-per-month (PMPM) cost for each policy in 2007 USD for a hypothetical one million member plan.
Results: Infants 32 to 35 wGA represented 0.08% of the plan. Approximately 20.2% of these infants met at least two or more of five AAP RFs. Expanding this list to include one additional RF of PSE, CLC, or YCA increased the percent of infants potentially prophylaxed to 29.9%, 23.9%, and 47%, respectively. Adding all three RFs to the list (two or more of eight) increased the percent of infants potentially prophylaxed to 55.6%, and increased payer costs by 9 cents PMPM.
Conclusion: Expanding the AAP RF criteria to include PSE, CLC, and YCA would identify more 32 to 35 wGA infants at high risk for severe RSV disease at an acceptable budget impact.