Hospital variation in admissions to neonatal intensive care units by diagnosis severity and category

Objective To examine interhospital variation in admissions to neonatal intensive care units (NICU) and reasons for the variation. Study design 2010–2012 linked birth certificate and hospital discharge data from 35 hospitals in California on live births at 35–42 weeks gestation and ≥1500 g birth weight were used. Hospital variation in NICU admission rates was assessed by coefficient of variation. Patient/hospital characteristics associated with NICU admissions were identified by multivariable regression. Results Among 276,489 newborns, 6.3% were admitted to NICU with 34.5% of them having mild diagnoses. There was high interhospital variation in overall risk-adjusted rate of NICU admission (coefficient of variation = 26.2) and NICU admission rates for mild diagnoses (coefficient of variation: 46.4–74.0), but lower variation for moderate/severe diagnoses (coefficient of variation: 8.8–14.1). Births at hospitals with more NICU beds had a higher likelihood of NICU admission. Conclusion Interhospital variation in NICU admissions is mostly driven by admissions for mild diagnoses, suggesting potential overuse.