Direct cost analyses of palivizumab treatment in a cohort of at-risk children: evidence from the North Carolina Medicaid Program.

Objective: Use of palivizumab prophylactic therapy reduces the occurrence of hospitalizations for serious respiratory syncytial virus (RSV) lower respiratory tract infections in at-risk infants. The direct cost-benefit of palivizumab prophylaxis for infants who are born at 32 to 35 weeks' estimated gestational age (EGA) during their first year of life has not been systematically examined. The objective of this study was to compare the direct costs of palivizumab prophylaxis and RSV treatment in infants who were born at 32 to 35 weeks EGA and received and did not receive palivizumab.

Methods: A cohort study was performed of infants who were younger than 1 year and were enrolled in an enhanced primary care case management model within the North Carolina Medicaid Program. Comparisons were made between infants who received (Synagis prophylaxis group) and did not receive palivizumab (nonprophylaxis group) during the study period. Cost was examined using the sum of Medicaid paid services for prophylaxis with palivizumab and treatment for RSV infections that occurred between October 1, 2002, and May 31, 2003. The Anderson framework was used to specify the regression cost models to compare the participants who received (Synagis prophylaxis) and did not receive (nonprophylaxis group) palivizumab. The primary outcomes were actual 7-month seasonal costs and standardized seasonal costs adjusting for the varied months of infant participation.

Results: The study sample included 185 Synagis prophylaxis and 182 nonprophylaxis participants who met the inclusion criteria. The average per-person total cost of RSV care and prophylaxis was 5117 dollars for the Synagis prophylaxis group and 371 dollars for the nonprophylaxis group. Five hospitalizations occurred in the prophylaxis group, and 12 occurred in the nonprophylaxis group (odds ratio: 0.27). No deaths occurred in either group.

Conclusions: Palivizumab administered to infants who were born at 32 to 35 weeks' EGA did not provide direct cost savings related to hospitalization or ambulatory care in a Medicaid population. The primary difference in cost between the groups was attributable to the palivizumab prophylaxis.