Changes in survival patterns of very low-birth-weight infants from 1980 to 1993
J. Roth, M. B. Resnick, M. Ariet, R. L. Carter, D. V. Eitzman, J. S. Curran, J. M. Cupoli, C. S. Mahan and R. L. Bucciarelli
Department of Pediatrics, University of Florida, USA.
OBJECTIVE: To determine changes in survival patterns among very
low-birth-weight ( < 1500 g) infants between 1980 and 1993. METHODS: The
records of 12,960 infants treated in nine perinatal intensive care centers
in Florida were analyzed on the basis of survival (discharged alive from
hospital) according to four independent variables: birth weight, race, sex,
and transport status. Survival curves were generated using log linear
regression techniques for each race by sex by transport status group.
RESULTS: Race, sex, and transport status correlated significantly with
survival: survival percentages were higher among black infants, female
infants, and infants transported to the perinatal intensive care centers
than among white infants, male infants, and those admitted initially to the
tertiary care centers. After 1985, 95% of neonates with birth weights
between 1200 and 1500 g survived. In addition, survival of 500- to 500-g
transported black male infants increased from zero to near 80% during the
13-year period; that of 500- to 550-g inborn white female infants rose from
35% to 70%. CONCLUSIONS: These results illustrate the value of taking into
account race, sex, and transport status in efforts to understand the
contribution that neonatal intensive care of extremely low-birth-weight
infants makes to the lowering of infant mortality, and of using
multivariable statistical procedures to generate predicted survival
probabilities for different subpopulations. These probabilities can be
applied to (1) predicting survival for specific subgroups of extremely
low-birth-weight infants, and (2) helping physicians develop clinical
guidelines for extending care to infants at the threshold of viability.
