title: Can major systematic reviews influence practice patterns? A case study of episiotomy trends.
abstract: OBJECTIVE
  Episiotomy is one of the most commonly performed procedures among women of childbearing age in the United States. In 2005, a major systematic review conducted by Hartmann and colleagues recommended against routine use of episiotomy and was widely covered in the media. We assessed the impact of the Hartman et al. study on episiotomy trend.
  
  
  METHODS
  Based on 100% hospital discharge data from eight states in 2003-2008, we used interrupted time series regression models to estimate the impact of the Hartman et al. review on episiotomy rates. We used mixed-effects regression models to assess whether interhospital variation was reduced over time.
  
  
  RESULTS
  After controlling for underlying trend, episiotomy rates dropped by 1.4 percentage points after Hartman et al. publication (p < 0.01 for spontaneous delivery; p < 0.1 for operative delivery). The publication has smaller effect on government hospitals as compared to private hospitals. Mixed effects models estimated negative correlation between cross-time and cross-hospital variations in episiotomy rates, indicating reduced cross-hospital variation over time.
  
  
  CONCLUSIONS
  Our results suggested that there has been a gradual decline in episiotomy rates over the period 2003-2008, and that synthesis of evidence showing harms from routine episiotomy had limited impact on practice patterns in the case of episiotomy. The experience of episiotomy illustrates the challenge of using comparative effectiveness and evidenced-based medicine to reduce use of unnecessary procedures.
authors.affiliation: Graduate School of Business and Public Policy, Naval Postgraduate School, 555 Dyer Road, Code GB, Monterey, CA, 93943, USA, yshen@nps.edu.
authors.forename: Yu-Chu
authors.initials: YC
authors.lastname: Shen
authors.forename: Wee Chung
authors.initials: WC
authors.lastname: Sim
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Caughey
authors.forename: David H
authors.initials: DH
authors.lastname: Howard
mesh_terms: D000328:Adult; D036861:Delivery, Obstetric / Q000379:methods* / Q000639:trends; D004841:Episiotomy / Q000706:statistics & numerical data / Q000639:trends*; D005260:Female; D016304:Hospitals, Private; D006779:Hospitals, Public; D006801:Humans; D016015:Logistic Models; D010818:Practice Patterns, Physicians'; D011247:Pregnancy; D014481:United States