1200 Caress: The Canadian Registry of Synagis (2006-2009)

Abstract

Background: Palivizumab is used for respiratory syncytial virus (RSV) prophylaxis in high risk children. Data on seasonality, risk factors, and outcomes are necessary to evaluate the impact of palivizumab on the incidence of RSV infections, minimize healthcare resources and identify which infant sub-sets are receiving prophylaxis. Objective: To evaluate the current management (utilization, compliance) of children at high-risk of RSV infection with palivizumab prophylaxis in tertiary care centers and community settings through the development of a Canadian Registry Database. Design/Methods: A prospective, observational, registry of infants who received at least 1 dose of palivizumab during the 2006-2009 RSV seasons from 26 Canadian sites. Neonatal and demographic data were collected from the parent/caregiver upon enrollment. Data on palivizumab utilization and compliance, including outcomes related to respiratory infection events were collected monthly. Results: 4926 infants aged 2 days to 47 months (mean=5.4 months) were enrolled. Participants were typically male (57.1%), Caucasian (71.5%) with an average gestational age (GA) of 32.2 ± 5.4 completed weeks. 3480 (70.6%) infants received palivizumab because they were premature only (i.e. =< 35 completed weeks GA), 397 (8.1%) required oxygen, 468 (9.5%) had congenital heart disease and 572 (11.6%) were prophylaxed for other risk factors such as CNS disorders, airway anomalies and cystic fibrosis. Patients received an average of 3.7 ± 1.5 injections, with 17,909 doses given overall. Only 6.2% of patients withdrew from the study. No directly, drug related serious adverse events were identified. 296 infants required a total of 351 hospitalizations for a spectrum of respiratory tract infections, resulting in a hospitalization rate of 6.0%. There were significant differences between indications for palivizumab (chi-square=32.7, p<0.005). The overall incidence of RSV positive hospitalization was 1.1%. Hospitalization rates were highest in non-Caucasian infants of aboriginal descent (17.9%, p<0.005). Hospitalized infants had a lower percentage of compliant injections (61.1% vs 67.7%, p=0.026). Conclusions: The RSV hospitalization rate observed in the 2006- 2009 RSV seasons was lower than that found in several published reports (range 1.3%-5.3%). The rates of RSV hospitalization may be decreasing for various reasons such as high compliance with palivizumab prophylaxis, variability in RSV epidemiology, hospital admission criteria and preventive education.