title: Hospital of Delivery and the Racial Differences in Late Preterm and Early-Term Labor Induction.
abstract: OBJECTIVE
  To estimate the interhospital differences in induction of labor (IOL) from 34(0/7) to 38(6/7) weeks' gestation by race/ethnicity.
  
  
  METHODS
  Women between 34 and 42 weeks' gestation during 1995 and 2009 in three states were identified using linked maternal and infant records. Women with prior cesarean delivery, premature rupture of membranes, gestational hypertension, who delivered at hospitals with < 100 annual births, or who had missing data were excluded. The outcomes were inductions at early-term (ETI: between 37(0/7) and 38(6/7) weeks') and late preterm (LPI: from 34(0/7)-36(6/7) weeks') gestations. Cox proportional hazard ratios (HR) were used to estimate the independent associations between race/ethnicity and hospital of delivery on ETI and LPI.
  
  
  RESULTS
  A total of 6.98 million eligible women delivered at 469 hospitals. ETI and LPI occurred in 3.20 and 0.40% of women, respectively. Non-Hispanic white women (3.99%) received ETI most commonly; conversely, LPI was highest among non-Hispanic black women (0.50%). In multivariable analyses, non-Hispanic black race was protective for ETI (HR = 0.89; p < 0.01) and was a risk factor for LPI (HR = 1.26; p < 0.01) after adjusting for patient factors and the delivery hospital.
  
  
  CONCLUSIONS
  Racial differences in ETI and LPI appear to be pervasive. Much of the unaccounted racial/ethnic variation remains seems secondary to within-hospital differences in selecting women for IOL.
authors.affiliation: Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois.
authors.forename: Karna
authors.initials: K
authors.lastname: Murthy
authors.affiliation: Division of Neonatology, Department of Pediatrics, Children's Hospital of Philadelphia and the Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Michelle
authors.initials: M
authors.lastname: Macheras
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: William A
authors.initials: WA
authors.lastname: Grobman
authors.affiliation: Division of Neonatology, Department of Pediatrics, Children's Hospital of Philadelphia and the Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lorch
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D002140:California / Q000453:epidemiology; D002821:Chorioamnionitis / Q000453:epidemiology; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D016640:Diabetes, Gestational / Q000453:epidemiology; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007674:Kidney Diseases / Q000453:epidemiology; D007751:Labor, Induced / Q000706:statistics & numerical data*; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D010414:Pennsylvania / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011254:Pregnancy in Diabetics / Q000453:epidemiology; D047928:Premature Birth; D016016:Proportional Hazards Models; D047929:Term Birth; D013959:Thyroid Diseases / Q000453:epidemiology; D014552:Urinary Tract Infections / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data*; D055815:Young Adult