title: Prediction of preterm birth in symptomatic women using decision tree modeling for biomarkers.
abstract: OBJECTIVE
  The objective of the study was to use recursive partitioning (RP) to identify gestational age-specific and threshold values for infectious and endocrine biomarkers of imminent delivery.
  
  
  METHODS
  RP was developed using a previously collected data set and then applied to a prospectively collected cohort of women in threatened preterm labor. Predictors of preterm birth were considered, including white blood cell count (WBC), corticotrophin-releasing hormone (CRH), cortisol, and maternal age.
  
  
  RESULTS
  At 22-27 weeks' gestation, WBC of greater than 12,000/mL was the most accurate predictor of delivery within 48 hours; at 28-31 weeks' gestation, CRH of greater than 684 pg/mL was the most accurate predictor; and at 32-26 weeks' gestation, CRH and maternal age were the most important variables.
  
  
  CONCLUSIONS
  These results indicate that maternal WBC greater than 12,000/mL prior to 28 weeks' gestation and CRH beyond 28 weeks are the most accurate biomarkers in predicting preterm birth within 48 hours. RP assists in establishing clinically relevant and gestational age-specific threshold levels for these variables.
authors.affiliation: Department of Epidemiology and Biostatistics, the University of Western Ontario, London, ON, Canada.
authors.forename: Jacquelyn L
authors.initials: JL
authors.lastname: Hill
authors.forename: M Karen
authors.initials: MK
authors.lastname: Campbell
authors.forename: Guang Yong
authors.initials: GY
authors.lastname: Zou
authors.forename: John R G
authors.initials: JR
authors.lastname: Challis
authors.forename: Gregor
authors.initials: G
authors.lastname: Reid
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Chisaka
authors.forename: Alan D
authors.initials: AD
authors.lastname: Bocking
mesh_terms: D000328:Adult; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D003663:Decision Trees; D005260:Female; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007958:Leukocyte Count; D011237:Predictive Value of Tests; D011247:Pregnancy; D047928:Premature Birth / Q000097:blood*
chemical_list: D015415:Biomarkers; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone