Rehospitalization for respiratory syncytial virus among premature infants

Objectives. New interventions to prevent respiratory syncytial virus (RSV) have recently become available. Clinical decisions about the use of these i nterventions require a better understanding of the incidence of and risk fa ctors for RSV. We sought to characterize the epidemiology of severe RSV dis ease among premature infants and to identify high-risk subgroups. Design. Retrospective cohort. Setting. Kaiser Permanente Northern California, July 1992 to April 1996. Participants. One thousand seven hundred twenty-one premature infants born at 23 to 36 weeks who were discharged from a neonatal intensive care nurser y (NICU) within 12 months before the December to March RSV season. A second ary analysis included 769 infants discharged during the RSV season. Outcome Measures. Hospitalization for RSV. Results. Of 1721 infants already home from the NICU at the start of the sea son, 3.2% were rehospitalized for RSV. In a multivariate model, risk factor s for RSV hospitalization included gestation less than or equal to 32 weeks (odds ratio [OR], 2.6), greater than or equal to 28 days of perinatal oxyg en (OR, 3.7), and NICU discharge during September to November (OR, 2.7). Pr edicted risk of hospitalization varied by subgroup, ranging from 1.2% to 24 .6%. Among 769 infants discharged from the NICU during the RSV season, 3.5% were rehospitalized for RSV during the same season; gestation and perinata l oxygen were not associated with admission. Conclusions. Most premature infants in this population were at less risk of severe RSV disease than previous studies in other populations have suggest ed. Preterm infants with a lower gestational age, a prolonged perinatal oxy gen requirement, and NICU discharge within 3 months of the RSV season were most likely to require hospitalization for RSV disease. Cost-effectiveness analyses are needed to help define the role of available prophylactic inter ventions.