Early Deaths in Chicago and New England

To the Editor.

We applaud Meadow, Reimshisel, and Lantos'¹attention to mortality risk in extremely low birth weight (ELBW) infants and its ethical implications. The authors have emphasized that illness severity and risk of mortality among ELBW infants are not static. This has important implications for clinical decision-making, ethics, and health policy.

We have a number of concerns about the authors' analyses. The study population is drawn from 5 to 7 years ago in an era when surfactant was still an investigational therapy and high-frequency ventilation was not widely used. These and perhaps other technologies have resulted in significantly enhanced survival of ELBW infants in the current era. If there is better survival in this era, has there been a change in the timing of death and the evolution of mortality risk? Such changes would substantially alter the conclusions reached by Meadow et al. Furthermore, our review of data presented in the article indicates that birth weight remains a potent determinant of mortality risk for ELBW infants through at least the first 2 weeks of life. The authors stated, “Once an infant had survived to day of life 4, the likelihood of subsequent survival to discharge was similar whether the birth weight was 690 or 960 g.” An analysis of the authors' own graph (Figure 3—page 638) by χ² (survival ∼72% vs 88%) is significantly different (P = .02). Similarly, using a χ² trend analysis, there was a significant decrease in mortality (P < .005) …