O0700 Oct.3: 4:40pm - Hospital Variation in Admissions to Neonatal Intensive Care Units by Diagnosis Severity and Category

Background: Trends toward increasing neonatal intensive care unit (NICU) admissions of neonates with higher gestational age, greater birth weight, and lower illness acuity over time have raised concern for potential misuse of NICUs. Studying variation in practices of NICU admissions across hospitals can provide a unique opportunity to inform reasons for potential overuse and identify areas for improvement.

Objective: To examine NICU admission rates by diagnosis severity and category and to evaluate inter-hospital variation in NICU admissions.

DESIGN/

Methods: Data from the 2010-2012 linked birth certificate and hospital discharge records from 35 hospitals in California were used to identify inborn live births at 35-42 weeks gestation and ≥1500 grams birthweight. Diagnoses of each infant were classified as severe, moderate or mild conditions, with mild conditions further subcategorized by mild respiratory, suspected infection, hypoglycemia, drug exposure/neonatal abstinence syndrome, and hyperbilirubinemia. Hospital variation in NICU admission rates (overall and by diagnosis category) was assessed using coefficient of variation (CV). Patient and hospital characteristics that were associated with the likelihood of NICU admission were identified using multivariable regression.

Results: Among 276,489 newborns meeting eligibility criteria, 6.3% were admitted to NICU with 34.5% of them having mild diagnoses. Across the 35 hospitals, there was high inter-hospital variation in overall risk-adjusted NICU admission rate (CV=26.2) and NICU admission rates for mild diagnoses (with CV ranging from 46.4 for hypoglycemia to 74.0 for suspected infection). In contrast, there was substantially lower variation in NICU admission rates for severe (CV=8.8) and moderate (CV=14.1) diagnoses. Births at hospitals with more NICU beds had a higher likelihood of NICU admission (adjusted odds ratio=1.97, 95% confidence interval: 1.06-3.65, for newborns at hospitals with higher versus lower than the median number of NICU beds per 1000 live inborn births). A hospital’s risk-adjusted rate of overall NICU admissions was positively correlated with the proportion of its NICU admissions for mild conditions (Spearman correlation coefficient=0.36, p=0.03).

Conclusions: Among infants born between 35 to 42 weeks gestation with a birth weight ≥1500 grams that were admitted to the NICU, one-third had mild conditions. There was high inter-hospital variation in overall NICU admission rates as well as in NICU admission rates for mild conditions. These findings suggest potential overuse of NICUs at some hospitals for mild conditions, calling for further efforts to identify strategies for reducing unnecessary NICU admissions.