Readmission with respiratory syncytial virus (RSV) infection among graduates from a neonatal intensive care unit.

We evaluated the incidence of readmission with respiratory syncytial virus (RSV) infection among the graduates of a regional Neonatal Intensive Care Unit (NICU), and characterized those who were rehospitalized. These data were used as a predictive tool to estimate the number of babies likely to suffer readmission with RSV for the year 2000 cohort. Using the published efficacies of palivizumab, the costs and benefits of protecting this cohort were assessed. Retrospective analysis of 2,507 NICU inpatient records from January 1, 1994-December 31, 1999 from the Royal Maternity Hospital, Belfast, were compared with data on positive RSV samples from 1,790 patients between January 1, 1995-December 31, 1999 from the Northern Ireland Regional Virus Laboratory. The analysis yielded 136 (7.6%) ex-NICU patients among the positive RSV samples over this 5-year period. Characteristic seasonal peaks of RSV infection with interseasonal variability were observed. Of those readmitted, 86.9% were hospitalized with RSV before their first birthday. A calculated readmission rate of 5.4% for all NICU graduates, and 6.4% for those <or=35 weeks, was found, leading to an expectation of 36 readmissions from the 668 NICU graduates in the year 2000 over the next 1-2 years, 20 of whom would be <or=35 weeks and 12 would be <or=32 weeks. A cost of pound 1.3 million would be required to protect the <or=35-week year 2000 cohort and prevent 11 readmissions. This equals pound 120,000 per admission prevented, or 28.2 patients treated to prevent 1 readmission. A readmission rate of 6.4% may differ from other studies, as it represents analysis of a greater number of RSV seasons. Using economic arguments alone, the cost of routine administration of Palivizumab to ex-NICU <or=35-week infants is prohibitive. A selective practice of immunizing those with chronic lung disease with a background of extreme prematurity over the November to March RSV season may be more cost-effective.