title: Factors associated with readmission in late-preterm infants: a matched case-control study.
abstract: OBJECTIVE
  The goal of this study was to evaluate risk factors for readmission among late-preterm (34-36 weeks' gestation) infants in clinical practice.
  
  
  METHODS
  This was a retrospective, matched case-control study of late-preterm infants receiving care across 8 regional hospitals in 2009 in the United States. Those readmitted within 28 days of birth were matched to non-readmitted infants at a ratio of 1:3 according to birth hospital, birth month, and gestational age. Step-wise modeling with likelihood ratio tests were used to develop a multivariable logistic regression model. A subgroup analysis of hyperbilirubinemia readmissions was also performed.
  
  
  RESULTS
  Of 1861 late-preterm infants delivered during the study period, 67 (3.6%) were readmitted within 28 days of birth. These were matched to 201 control infants, for a final sample of 268 infants. In multivariable regression, each additional day in length of stay was associated with a significantly reduced odds ratio (OR) for readmission (0.57, P = .004); however, for those infants delivered vaginally, there was no significant association between length of stay and readmission (adjusted OR: 1.08, P = .16). A stronger inverse relationship was observed in subgroup analysis for hyperbilirubinemia readmissions, with the adjusted OR associated with increased length of stay 0.40 (P = .002) for infants born by cesarean delivery but 1.14 (P = .27) for those delivered vaginally.
  
  
  CONCLUSIONS
  Infants born via cesarean delivery with longer length of hospital stay have a decreased risk for readmission. As hospitals implement protocols to standardize length of stay, mode of delivery may be a useful factor to identify late-preterm infants at higher risk for readmission.
authors.affiliation: Divisions of Neonatology and Perinatal Institute laurel.moyer@cchmc.org.
authors.forename: Laurel B
authors.initials: LB
authors.lastname: Moyer
authors.affiliation: Divisions of Neonatology and Perinatal Institute Hospital Medicine, Cincinnati Children's Research Foundation and Department of Pediatrics.
authors.forename: Neera K
authors.initials: NK
authors.lastname: Goyal
authors.affiliation: Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio; and.
authors.forename: Jareen
authors.initials: J
authors.lastname: Meinzen-Derr
authors.affiliation: Divisions of Neonatology and Perinatal Institute.
authors.forename: Laura P
authors.initials: LP
authors.lastname: Ward
authors.affiliation: Department of Obstetrics, St. Elizabeth's Healthcare.
authors.forename: Christina L
authors.initials: CL
authors.lastname: Rust
authors.affiliation: Divisions of Neonatology and Perinatal Institute.
authors.forename: Scott L
authors.initials: SL
authors.lastname: Wexelblatt
authors.affiliation: Divisions of Neonatology and Perinatal Institute.
authors.forename: James M
authors.initials: JM
authors.lastname: Greenberg
mesh_terms: D016022:Case-Control Studies; D002585:Cesarean Section; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D006932:Hyperbilirubinemia / Q000628:therapy; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000628:therapy*; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D016017:Odds Ratio; D010359:Patient Readmission / Q000706:statistics & numerical data*
keywords: cesarean delivery; delivery; hyperbilirubinemia; late preterm; length of stay; readmission