Clinical predictors and institutional variation in home oxygen use in preterm infants.

To assess home oxygen use in preterm infants, identify risk factors predicting home oxygen use, and quantify the extent of institutional variation in home oxygen use across neonatal intensive care units. We conducted a retrospective cohort analysis of surviving infants of 23- to 31-week gestational age discharged home in 2009, with de-identified electronic medical record information from the Pediatrix Clinical Data Warehouse. Mixed-effects logistic regression quantified clinical risk factors and institutional variation affecting home oxygen use. A total of 8167 infants were identified. Home oxygen use varied by gestational age, from 59% of infants 23 to 24 weeks gestational age to 7% of infants 29 to 31 weeks gestational age. Other risk factors included small for gestational age, congenital anomalies, mechanical ventilation in the first 72 hours, fraction of inhaled oxygen >0.4 in the first 72 hours, and patent ductus arteriosus. After adjusting for clinical risk factors, there was still a 4- to 5-fold difference in institutions' odds of home oxygen use. Home oxygen use was common in infants of earlier gestational ages and infants with more severe respiratory illness. Institutional variation accounted for 4- to 5-fold variation in home oxygen use. Families should be counseled about the likelihood of home oxygen use, and prospective research must identify optimal treatment strategies for high-risk infants.