Variability in 28-Day Outcomes for Very Low Birth Weight Infants: An Analysis of 11 Neonatal Intensive Care Units
A retrospective study of all infants weighing 701 to 1,500 g born at 11 neonatal intensive care centers during 1983 and 1984 was performed to determine whether two specific 28-day outcomes, survival and survival without the need for supplemental oxygen, varied among the centers. Survival without the need for supplemental oxygen was chosen as a reflection of infants surviving without chronic lung disease. There were 1,776 live-born infants delivered during the 2-year study period. Of these infants, 85% (1,512) survived 28 days, a range of 80% to 92% at the individual centers. A total of 60% (1,056) of the infants were alive without supplemental oxygen on day 28, a range of 5l% to 70% at the individual centers. Multivariate analysis demonstrated that both survival on day 28 (χ2 = 23.9, P < .01) and survival without supplemental oxygen on day 28 (χ2 = 44.2, P < .0001) varied significantly among centers after the effects of birth weight, gender, and race were taken into account. Female gender, nonwhite race, and increased birth weight were factors associated with improved rates of survival and survival without supplemental oxygen. The magnitude of outcome variation among centers was estimated by using the logistic regression models to predict what the outcomes would be if each center were to treat a standardized population consisting of all 1,776 study infants. Predicted survival rates varied by as much as 15% and the predicted rates for survival without supplemental oxygen varied by nearly 17% between centers with the highest and lowest rates. The differences in outcomes observed at the centers did not correlate with the number of live births at the centers or with the scores on a simple respiratory practices questionnaire. It was concluded that 28-day outcomes for very low birth weight infants vary significantly among different neonatal intensive care centers. Potential sources of this variation include undetected population differences in neonatal disease severity and differences in the techniques of both obstetrical and neonatal care.
- Received May 26, 1987.
- Accepted November 30, 1987.
- Copyright © 1988 by the American Academy of Pediatrics