Predictors of hospital postdischarge infant mortality: implications for high-risk infant follow-up efforts.

The association between maternal/infant characteristics and postdischarge mortality was determined for 19,573 infants from a single regional perinatal center. Postdischarge mortality was not associated with infant sex or ethnicity, mother's marital status, education, method of delivery, or income status. Mortality risk was statistically increased for infants who were neonatal intensive care unit graduates, of low birth weight, preterm, or small for gestational age. Infants who were either of low birth weight, neonatal intensive care unit graduates, or preterm represented 38% of hospital discharges and 64% of postdischarge deaths. Mortality odds for low-birth-weight infants exceeded that of neonatal intensive care unit graduates or preterm infants. Within these high-risk groups, mortality was further increased for infants with pulmonary interstitial emphysema, patent ductus arteriosus, bronchopulmonary dysplasia, hyaline membrane disease, apnea, or intraventricular hemorrhage III/IV. There were no postdischarge deaths among infants with meconium aspiration, persistent fetal circulation, or necrotizing enterocolitis. Partitioning infant mortality attributable to a single tertiary center suggested that 73.5% of the deaths occurred in infants who were continuously hospitalized from birth; 1.7% of the deaths occurred after discharge in infants who had lethal anomalies and were not expected to survive; 9.0% of the deaths occurred after discharge in infants without a selected risk factor; and 15.8% of the deaths occurred after discharge in infants with at least one high-risk characteristic.