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Updated: May 5, 2026
Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Association between risk-adjusted mortality and severe morbidity in very low birth weight infants: a multicenter
Guillermo Marshall1,2, Jose Luis Tapia3,4, Angélica Dominguez5
1School of Public Health, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile. guillermo.marshall@uc.cl.
Background:
Very low birth weight infants (VLBWI) are at high risk of mortality and severe morbidities. While many neonatal networks monitor risk-adjusted outcomes separately, the relationship between mortality and major morbidities across centers remains unclear.
Objective:
To evaluate the association between risk-adjusted in-hospital mortality and six major morbidities in VLBWI across 20 South American NICUs participating in the NEOCOSUR Network between 2011 and 2023.
Methods:
Retrospective cohort study including 14,100 VLBWI (500-1500 g) from 20 NICUs in Argentina, Chile, Paraguay, Peru, and Uruguay. Observed-to-expected (O/E) ratios for mortality and for each morbidity-late-onset sepsis, bronchopulmonary dysplasia at 36 weeks (BPD), severe intraventricular hemorrhage (IVH grade III-IV), retinopathy of prematurity (ROP ≥ stage III), necrotizing enterocolitis (NEC ≥ stage II), and periventricular leukomalacia (PVL)-were calculated using logistic regression models adjusted for perinatal risk factors. Center-level associations were evaluated using Poisson regression models.
Results:
O/E mortality varied widely across centers (range from 0.62 to 1.48), with 7 centers showing significantly lower-than-expected mortality and 4 with higher-than-expected values. Significant positive associations were found between mortality O/E and O/E of late-onset sepsis (χ² = 53.6, p < 0.01), severe IVH (χ² = 18.0, p < 0.01), ROP (χ² = 38.0, p < 0.01), and PVL (χ² = 23.4, p < 0.01). An inverse association was observed between mortality and BPD (χ² = 36.2, p < 0.01). No significant association was found for NEC.
Conclusions:
Centers with higher-than-expected mortality also showed excess rates of several severe morbidities, suggesting that shared care practices may be associated with multiple outcomes. The inverse association with BPD may reflect a survival bias. These findings support the integration of multiple adjusted outcomes in quality benchmarking across NICUs.
