title: A 'busy day' effect on perinatal complications of delivery on weekends: a retrospective cohort study.
abstract: To evaluate whether busy days on a labour and delivery unit are associated with maternal and neonatal complications of childbirth in California hospitals, accounting for weekday/weekend births.
  
  
  
  This is a population-based retrospective cohort study.
  
  
  
  Linked vital statistics/patient discharge data for California births between 2009 and 2010 from the Office of Statewide Health Planning and Development.
  
  
  
  All singleton, cephalic, non-anomalous California births between 2009 and 2010 (N=724 967).
  
  
  
  The key exposure was high daily obstetric volume, defined as giving birth on a day when the number of births exceeded the hospital-specific 75th percentile of daily delivery volume. Outcomes were a range of maternal and neonatal complications.
  
  
  
  Several maternal and neonatal complications were increased on high-volume days and weekends following adjustment for maternal demographics, annual hospital birth volume and teaching hospital status. For example, compared with low-volume weekdays, the odds of Apgar <7 on low-volume weekend days and high-volume weekend days were 11% (adjusted OR (aOR) 1.11, CI 1.03 to 1.21) and 29% higher (aOR 1.29, CI 1.10 to 1.52), respectively. High volume was associated with increased odds of neonatal seizures on weekdays (aOR 1.33, CI 1.01 to 1.71) and haemorrhage on weekends (aOR 1.11, CI 1.01 to 1.22). After accounting for between-hospital variation, weekend delivery remained significantly associated with increased odds of Apgar score <7, neonatal intensive care unit admission, prolonged maternal length of stay and the odds of neonatal seizures remained increased on high-volume weekdays.
  
  
  
  Our findings suggest that weekend delivery is a consistent risk factor for a range of perinatal complications and there may be variability in how well hospitals handle surges in volume.
authors.affiliation: Department of Obstetrics & Gynecology/Public Health & Preventive Medicine, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Snowden
authors.affiliation: Division of Health Policy and Management, University of Minnesota School of Public Health, Minneapolis, Minnesota, USA.
authors.forename: Katy Backes
authors.initials: KB
authors.lastname: Kozhimannil
authors.affiliation: Department of Obstetrics & Gynecology, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Ifeoma
authors.initials: I
authors.lastname: Muoto
authors.affiliation: Department of Obstetrics & Gynecology, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Caughey
authors.affiliation: Emergency Medicine, Oregon Health and Science University, Portland, Oregon, USA.
authors.forename: K John
authors.initials: KJ
authors.lastname: McConnell
mesh_terms: D000328:Adult; D039602:After-Hours Care / Q000706:statistics & numerical data*; D002140:California / Q000453:epidemiology; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: Health services research; Obstetrics and gynecology; Quality improvement