title: Adoption of diagnostic technology and variation in caesarean section rates: a test of the practice style hypothesis in Norway.
abstract: OBJECTIVE
  To examine whether the introduction of advanced diagnostic technology in maternity care has led to less variation in type of delivery between hospitals in Norway.
  
  
  METHODS
  The Medical Birth Registry of Norway provided detailed medical information for 1.7 million deliveries from 1967 to 2005. Information about diagnostic technology was collected directly from the maternity units.
  
  
  METHODS
  The data were analyzed using a two-level binary logistic model with Caesarean section as the outcome measure. Level one contained variables that characterized the health status of the mother and child. Hospitals are level two. A heterogeneous variance structure was specified for the hospital level, where the error variance was allowed to vary according to the following types of diagnostic technology: two-dimensional ultrasound, cardiotocography, ST waveform analysis, and fetal blood analyses.
  
  
  RESULTS
  There was a marked variation in Caesarean section rates between hospitals up to 1973. After this the variation diminished markedly. This was due to the introduction of ultrasound and cardiotocography.
  
  
  CONCLUSIONS
  Diagnostic technology reduced clinical uncertainty about the diagnosis of risk factors of the mother and child during delivery, and variation in type of delivery between hospitals was reduced accordingly. The results support the practice style hypothesis.
authors.affiliation: Section of Community Dentistry, University of Oslo and Akershus University Hospital, Blindern, Oslo, Norway. josteing@odont.uio.no
authors.forename: Jostein
authors.initials: J
authors.lastname: Grytten
authors.forename: Lars
authors.initials: L
authors.lastname: Monkerud
authors.forename: Rune
authors.initials: R
authors.lastname: Sørensen
mesh_terms: D015148:Cardiotocography; D002585:Cesarean Section / Q000706:statistics & numerical data* / Q000639:trends; D019937:Diagnostic Techniques and Procedures / Q000706:statistics & numerical data*; D004562:Electrocardiography; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D009664:Norway; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data* / Q000639:trends; D011247:Pregnancy; D014463:Ultrasonography; D035501:Uncertainty