Background: Down syndrome (DS) is a risk factor for respiratory syncytial virus (RSV) hospitalization, but little is known about prophylaxis in these children.
Methods: CARESS is a prospective registry of children who received ≥1 dose of palivizumab during the 2006–2012 RSV seasons across 32 sites in Canada. The objective was to compare respiratory illness hospitalization and RSV hospitalization (RSVH) hazard ratios in DS children aged <2 years who received palivizumab versus children who received prophylaxis for standard indications (SI) and for other medical illnesses (MI).
Results: 13,310 children were enrolled; DS (600; 4.5%), SI (11,081; 83.3%) and MI (1629, 12.2%), with DS children increasing over the duration from 0.1% (2006) to 4.5% (2012). Participants were significantly different in mean birth weight, gestational and enrollment age and risk factors. Children in each group received an average of 4.3 ± 1.4 (DS), 4.1 ± 1.6 (SI) and 4.5 ± 1.4 (MI) palivizumab injections per RSV season, with DS, differing significantly from SI [F(2, 13,307) = 43.6, P = 0.01] but not MI [F(2, 13 307) = 43.6, P = 0.07]. Compliance rates were similar across the groups. While a significantly greater proportion of SI children had RIHs compared with DS, [hazard ratio: 0.64 (0.48–0.84); P = 0.001] hazard ratios were similar for DS and MI. RSVH incidence rates were: 1.53%, 1.45% and 2.27% for DS, SI and MI, respectively. Neither group nor compliance affected time to RSVH.
Conclusions: The proportion of DS children who received palivizumab in CARESS has increased almost 45-fold. RSVH rates were low in DS following prophylaxis and hazards were similar to those found in SI and MI.
From the *Department of Pediatrics, McMaster University, Hamilton, Ontario; †Department of Pediatrics, University of Calgary, Calgary, Alberta; and ‡Medical Outcomes and Research in Economics (MORE®) Research Group, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Accepted for publication August 21, 2013.
B.P., I.M. and K.L. received investigator-initiated research funding from Abbvie Inc. for this study and have been compensated as advisors and/or lecturers for Abbvie and MedImmune. I.M. has received a research grant from MedImmune. A.L. has received a speaker’s honorarium from Abbvie. H.Y. has no conflicts of interest to declare. B.P. wrote the first draft of the article and no honorarium, grant or other form of payment was given to anyone to produce the article. The authors have no other funding or conflicts of interest to disclose.
Address for correspondence: Krista L. Lanctôt, PhD, MORE® Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Room FG-08, Toronto, Ontario M4N 3M5, Canada. E-mail: firstname.lastname@example.org.