Level III neonatal intensive care unit heterogeneity in patients, services, and outcomes

OBJECTIVES: Level III NICUs share one AAP level of care designation. We characterized variation, identified sub-classes, and compared sub-class outcomes. STUDY DESIGN: This retrospective cohort analysis of level III NICUs in Florida, Michigan, Oregon, Pennsylvania, and South Carolina used linked hospital discharge-vital statistics data (2010-2020). Included hospitals had ≥10 births annually and infants had gestational age <32 weeks and/or birth weight <1500 g. We characterized NICU-level heterogeneity; used latent class analysis (LCA) to obtain sub-classes; and compared risk-adjusted outcomes with multivariable Poisson regression. RESULTS: Among 163 NICUs (1518 hospital-years) there was significant variation. LCA identified five sub-classes (3a-e). Preterm volume and procedural intensity rose with acuity (3a lowest, 3d/3e highest). Higher acuity was associated with lower mortality but higher morbidity (3d vs. 3a: death: IRR 0.59 [95% CI 0.54-0.65]; morbidity: 2.84 [2.43-3.31]). CONCLUSIONS: Level III NICUs are heterogeneous and comprise five sub-classes with divergent outcomes. Sub-classification may facilitate risk-appropriate care.