title: Examining caesarean section rates in Canada using the Robson classification system.
abstract: OBJECTIVE
  To determine the groups within the obstetric population contributing most substantially to the Caesarean section rate in five Canadian provinces.
  
  
  METHODS
  Hospital births from five participating provinces were grouped into Robson's 10 mutually exclusive and totally inclusive classification categories. The relative contribution of each group to the overall CS rate, relative size of group, and CS rate were calculated for British Columbia, Alberta, Ontario, Nova Scotia, and Newfoundland and Labrador for the four-year period from 2007-2008 to 2010-2011.
  
  
  RESULTS
  In all five provinces (accounting for approximately 64% of births in Canada), and for all years examined, the group making the largest relative contribution to the CS rate was women with at least one previous CS and a term, singleton, cephalic-presenting pregnancy (Robson Group 5). The CS rate for this group ranged from 76.1% in Alberta to 89.9% in Newfoundland and Labrador in 2010 to 2011, accounting for 11.3% of all deliveries. The rate of CS for Group 5 decreased slightly over the four years, except in Ontario. The next largest contributing group was nulliparous women with a term, singleton, cephalic-presenting pregnancy. Those with induced labour or Caesarean section before labour (Robson Group 2) had CS rates ranging from 34.4% in Nova Scotia to 44.6% in British Columbia (accounting for 13.1% of all deliveries), and those with spontaneous onset of labour (Robson Group 1) had CS rates of 14.5% to 20.3% in 2010 to 2011 (accounting for 23.6% of all deliveries).
  
  
  CONCLUSIONS
  All hospitals and health authorities can use this standardized classification system as part of a quality improvement initiative to monitor Caesarean section rates. This classification system identifies relevant areas for interventions and resources to reduce rates of Caesarean section.
authors.affiliation: Better Outcomes Registry & Network (BORN) Ontario, Ottawa ON; Children's Hospital of Eastern Ontario Research Institute, Ottawa ON.
authors.forename: Sherrie
authors.initials: S
authors.lastname: Kelly
authors.affiliation: Better Outcomes Registry & Network (BORN) Ontario, Ottawa ON; Children's Hospital of Eastern Ontario Research Institute, Ottawa ON.
authors.forename: Ann
authors.initials: A
authors.lastname: Sprague
authors.affiliation: Better Outcomes Registry & Network (BORN) Ontario, Ottawa ON; Children's Hospital of Eastern Ontario Research Institute, Ottawa ON.
authors.forename: Deshayne B
authors.initials: DB
authors.lastname: Fell
authors.affiliation: Newfoundland and Labrador Provincial Perinatal Program, St. John's NL.
authors.forename: Phil
authors.initials: P
authors.lastname: Murphy
authors.affiliation: Alberta Perinatal Health Program, Edmonton AB.
authors.forename: Nancy
authors.initials: N
authors.lastname: Aelicks
authors.affiliation: Ottawa Hospital Research Institute, Ottawa ON.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Reproductive Care Program of Nova Scotia, Halifax NS.
authors.forename: John
authors.initials: J
authors.lastname: Fahey
authors.affiliation: Reproductive Care Program of Nova Scotia, Halifax NS.
authors.forename: Leeanne
authors.initials: L
authors.lastname: Lauzon
authors.affiliation: Perinatal Services British Columbia, Vancouver BC.
authors.forename: Heather
authors.initials: H
authors.lastname: Scott
authors.affiliation: Faculty of Medicine, University of Ottawa, Ottawa ON.
authors.forename: Lily
authors.initials: L
authors.lastname: Lee
authors.affiliation: Faculty of Medicine, University of Ottawa, Ottawa ON.
authors.forename: Brooke
authors.initials: B
authors.lastname: Kinniburgh
authors.affiliation: Better Outcomes Registry & Network (BORN) Ontario, Ottawa ON; Children's Hospital of Eastern Ontario Research Institute, Ottawa ON.
authors.forename: Monica
authors.initials: M
authors.lastname: Prince
authors.affiliation: Better Outcomes Registry & Network (BORN) Ontario, Ottawa ON; Children's Hospital of Eastern Ontario Research Institute, Ottawa ON; Ottawa Hospital Research Institute, Ottawa ON; Faculty of Medicine, University of Ottawa, Ottawa ON.
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
mesh_terms: D002170:Canada; D002585:Cesarean Section / Q000706:statistics & numerical data*; D017604:Cesarean Section, Repeat; D005260:Female; D005865:Gestational Age; D006801:Humans; D007746:Labor Presentation; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D058996:Quality Improvement