OBJECTIVES: Congenital diaphragmatic hernia (CDH) continues to remain a significant cause of neonatal morbidity and mortality. Previous studies have suggested hospital volume is an independent predictor of in-hospital mortality. We sought to validate this effect using a large National database incorporating 38 free-standing Children’s Hospitals in the United States.
METHODS: Infants whom underwent repair of CDH from 2000-2008 at Pediatric Health Information Systems (PHIS)-member hospitals were evaluated. Using generalized linear mixed models with random effects, we computed the risk adjusted odds ratio of mortality by yearly hospital volume, after adjustment for salient patient and hospital characteristics.
RESULTS: There were 2231 infants whom underwent repair with an overall survival of 82%. Average yearly hospital volume varied from 1.4 to 17.5 cases per year. Smaller birthweight, year of birth, need for governmental assistance, chromosomal abnormalities, longer time to repair, and requirement for Extracorporeal Membrane Oxygenation (ECMO) or Nitric Oxide were all independently associated with mortality (Table). Compared to low volume, medium and high volume hospitals have a significantly lower mortality. The rate of ECMO use at each facility was not independently associated with mortality.
CONCLUSION: This large, population based study suggests that hospitals who perform high volumes of CDH repairs achieve lower in-hospital mortality. This data support the paradigm of regionalized centers of excellence for the management of infants with this morbid condition.

Independent Risk Factors for Mortality in Children with CDH

		Univariate Analysis	Multivariate Analysis
Risk Factor		Crude OR	Adjusted OR	p-Value
Birthweight	per Kg	0.63 (0.53-0.75)	0.49 (0.39-0.63)	<0.0001
Year of Birth	per year from 2000	0.99 (0.95-1.05)	0.89 (0.84-0.95)	0.0006
Payer Source	Government Insurance	1	1
	Private Insurance	0.60 (0.46-0.77)	0.60 (0.43-0.84)	0.004
	Self-Insured	0.55 (0.21-1.46)	0.76 (0.22-2.66)	0.6
	Other	0.69 (0.50-0.96)	0.93 (0.61-1.44)	0.8
Chromosomal Abnormalities	Present vs. Absent	2.34 (1.24-4.43)	4.60 (1.81-11.71)	0.001
Time To Repair	per Week	1.34 (1.24-1.46)	1.07 (1.00-1.23)	0.047
Need for ECMO	Present vs. Absent	18.27 (13.62-24.52)	10.54 (7.28-15.24)	<0.0001
Need for Nitric Oxide	Present vs. Absent	9.59 (7.11-12.92)	4.54 (3.02-6.84)	<0.0001
Hospital Volume	Low Volume (<6 cases/year)	1	1
	Medium Volume (6-13 cases/year)	0.75 (0.50-1.10)	0.55 (0.33-0.91)	0.02
	High Volume (>13 cases/year)	0.52 (0.30-0.89)	0.33 (0.14-0.74)	0.008
Hospital ECMO Rate	per 10%	1.34 (1.17-1.54)	1.10 (0.90-1.34)	0.25