Abstract 1467 Neonatal Epidemiology and Follow-up Poster Symposium, Monday, 5/3

Objective: To review the trends in Respiratory Distress Syndrome (RDS) related mortality since the introduction of surfactant into the care of infants. Methods: We used U.S. Vital Statistic data for the years 1987 to 1995. Linked birth and infant death file data were available for the years 1987 to 1991 and 1995. U.S. Natality and Mortality files were used for the years 1992 to 1994. Results: While overall infant mortality decreased 25% over the 9 year period from a rate of 979 deaths/100,000 live births (LB) to a rate of 736, mortality attributed to RDS decreased 56% from a rate of 84 to 37. The drop in RDS mortality accounted for 19% of the drop in the overall infant mortality rate during this period. There was a significant drop in RDS mortality for both black and white populations, however, the crude black:white relative risk for RDS related mortality increased from 2.02 in 1987 to 2.76 in 1995. The largest and most consistent drop in RDS related mortality occurred in the 2000 to 2499 gram weight category, average annual decrease of 20%, while the smallest decrease occurred in the less than 500 gram birth weight category, average annual decline of 3%. Postneonatal RDS mortality rates dropped from 5.19/100,000LB to 2.51. There was a change in the distribution of the underlying causes of death over the 9 year period with an increase in the proportion of mortality attributed to prematurity. The proportion of mortality attributed to categories of respiratory disorders including RDS, bronchopulmonary dysplasia, respiratory insufficiency, and respiratory failure decreased. Conclusion: Since the advent of surfactant there has been a marked reduction in mortality attributed to RDS. However, the decline in RDS mortality began in the larger birth weight groups prior to 1990, suggesting that other improvements in care, besides the introduction of surfactant, contributed to the decline. The largest reductions in RDS mortality occurred in birth weights of greater than 1000 grams. Of concern is the increasing disparity between black and white RDS related mortality.