Predictors of death or bronchopulmonary dysplasia in preterm infants with respiratory failure

Abstract

Objectives: To identify the variables that predict death/physiologic bronchopulmonary dysplasia (BPD) in preterm infants with severe respiratory failure.

Study design: The study was a secondary analysis of data from the NICHD Neonatal Research Network trial of inhaled nitric oxide (iNO) in preterm infants. Stepwise logistic regression models and Classification and Regression Tree (CART) models were developed for the outcome of death or physiologic BPD (O(2) at 36 weeks post-menstrual age).

Result: Death and/or BPD was associated with lower birth weight, higher oxygen requirement, male gender, additional surfactant doses, higher oxygenation index and outborn status, but not the magnitude of response in PaO(2) to iNO. The positive predictive value of the CART model was 82% at 95% sensitivity.

Conclusions: The major factors associated with death/BPD were an increased severity of respiratory failure, lower birth weight, male gender and outborn status, but not the magnitude of initial response to iNO.

Figure 1. CART model for death/physiologic BPD

The dichotomous outcome of death or physiologic BPD at 36 weeks’ post-menstrual age is predicted by this decision tree. In each node (rectangle), the category “0” or “1” refers to the absence or presence of death/BPD, respectively, and the percentages and “n” refer to the infants in each of the categories. The increment in positive predictive value with the variable under consideration is shown as the “improvement” (e.g. 0.09 = a 9% increase in positive predictive value).