Association between bronchopulmonary dysplasia severity and its risk factors and long-term outcomes in three definitions: a historical cohort study

Objective To compare the association of the severity categories of the 2001-National Institutes of Health (NIH), the 2018-NIH and the 2019-Jensen bronchopulmonary dysplasia (BPD) definitions with neurodevelopmental and respiratory outcomes at 2 and 5 years' corrected age (CA), and several BPD risk factors. Design Single-centre historical cohort study with retrospective data collection. Setting Infants born between 2009 and 2015 at the Amsterdam University Medical Centers, location Amsterdam Medical Center. Patients Preterm infants born at gestational age (GA) <30 weeks and surviving up to 36 weeks' postmenstrual age. Interventions Perinatal characteristics, (social) demographics and comorbidities were collected from the electronic patient records. Main outcome measures The primary outcomes were neurodevelopmental impairment (NDI) or late death, and respiratory morbidity at 2 and 5 years' CA. Using logistic regression and Brier scores, we investigated if the ordinal grade severity is associated with incremental increase of adverse long-term outcomes. Results 584 preterm infants (median GA: 28.1 weeks) were included and classified according to the three BPD definitions. None of the definitions showed a clear ordinal incremental increase of risk for any of the outcomes with increasing severity classification. No significant differences were found between the three BPD definitions (Brier scores 0.169-0.230). Respiratory interventions, but not GA, birth weight or small for GA, showed an ordinal relationship with BPD severity in all three BPD definitions. Conclusion The severity classification of three BPD definitions showed low accuracy of the probability forecast on NDI or late death and respiratory morbidity at 2 and 5 years' CA, with no differences between the definitions.