title: PP087. Multicenter external validation and recalibration of a model for preconceptional prediction of recurrent early-onset preeclampsia.
abstract: In an earlier paper we reported on the development of a model aimed at the prediction of preeclampsia recurrence, based on variables obtained before the next pregnancy (fasting glucose, BMI, previous birth of a small-for-gestational-age infant, duration of the previous pregnancy, and the presence of hypertension).
  
  
  
  To externally validate and recalibrate the prediction model for the risk of recurrence of early-onset preeclampsia.
  
  
  
  We collected data about course and outcome of the next ongoing pregnancy in 229 women with a history of early-onset preeclampsia. Recurrence was defined as preeclampsia requiring delivery before 34 weeks. We computed risk of recurrence and assessed model performance. In addition, we constructed a table comparing sensitivity, specificity, and predictive values for different suggested risk-thresholds.
  
  
  
  Early-onset preeclampsia recurred in 6.6% of women. The model systematically underestimated recurrence risk. The model's discriminative ability was modest, the area under the receiver operating characteristic curve was 58.9% (95% CI: 45.1 - 72.7). Using relevant risk-thresholds, the model created groups that were only moderately different in terms of their average risk of recurrent preeclampsia (Table 1).
  
  
  
  Compared to an AUC of 65% in the development cohort, the discriminate ability of the model was diminished. It had inadequate performance to classify women into clinically relevant risk groups.
authors.forename: Sander
authors.initials: S
authors.lastname: van Kuijk
authors.forename: Denise
authors.initials: D
authors.lastname: Delahaije
authors.forename: Carmen
authors.initials: C
authors.lastname: Dirksen
authors.forename: Hubertina C J
authors.initials: HC
authors.lastname: Scheepers
authors.forename: Marc
authors.initials: M
authors.lastname: Spaanderman
authors.forename: W
authors.initials: W
authors.lastname: Ganzevoort
authors.forename: Hans
authors.initials: H
authors.lastname: Duvekot
authors.forename: M A
authors.initials: MA
authors.lastname: Oudijk
authors.forename: M G
authors.initials: MG
authors.lastname: van Pampus
authors.forename: Peter
authors.initials: P
authors.lastname: von Dadelszen
authors.forename: Louis L
authors.initials: LL
authors.lastname: Peeters
authors.forename: Luc
authors.initials: L
authors.lastname: Smiths