Summary of Analysis of RSV Hospitalization
| Placebo | Palivizumab | % Reduction (95% CI) | P Value | |
|---|---|---|---|---|
| Primary analysis (incidence of RSV hospitalizations)* | 53 /500 (10.6%) | 48 /1002 (4.8%) | 55% (38, 72) | <.001 |
| Alternative analysis (Kaplan-Meier†) | 53 /500 (10.6%) | 48 /1002 (4.8%) | 55% (38, 72) | <.001 |
| Sensitivity analyses | ||||
| Dropout before 150 days and no endpoint‡ | 53 /500 (10.6%) | 49 /1002 (4.9%) | 55% (38, 72) | <.001 |
| Respiratory hospitalization but no RSV test done§ | 56 /500 (11.2%) | 54 /1002 (5.4%) | 52% (35, 69) | <.001 |
| Primary inclusion populations | ||||
| Premature (no BPD) | 19 /234 (8.1%) | 9 /506 (1.8%) | 78% (66, 90) | <.001 |
| BPD | 34 /266 (12.8%) | 39 /496 (7.9%) | 39% (20, 58) | .038 |
Abbreviations: RSV, respiratory syncytial virus; CI, confidence interval; BPD, bronchopulmonary dysplasia.
↵* Fisher's exact test.
↵† Kaplan-Meier estimate of the proportion at 150 days. Deaths before RSV hospitalization, withdrawals, and lost events were treated as censored.
↵‡ The number of children who stopped follow-up before day 150 and had no endpoint through the last follow-up visit and would have been hospitalized if the proportion hospitalized was equal to that of the other treatment group added to observed incidence of RSV hospitalization. For placebo 5 children × 0.048 (RSV hospitalization rate in palivizumab group) = 0.24 (0 added events); for palivizumab 11 children × 0.106 (RSV hospitalization in placebo) = 1.17 (1 added event).
↵§ Number of children with respiratory hospitalizations and evidence of infection (coryza, fever) who had no alternative etiology added to observed incidence of RSV hospitalization. Three no antigen respiratory hospitalizations (0.6%) in the placebo group and 6 (0.6%) in the palizivumab group.