title: Receiver-operator characteristic, efficiency analysis, and predictive value of serum progesterone concentration as a test for abnormal gestations.
abstract: OBJECTIVE
  Our objective was to determine if a discriminatory progesterone concentration could be established that confidently predicted abnormal early gestations.
  
  
  METHODS
  We analyzed differences in progesterone concentrations between normal (n = 40) and abnormal (n = 34) pregnancies during the first 49 days of gestation. The receiver-operator characteristic curve, test efficiency, and predictive value of serum progesterone to discriminate between an abnormal and normal first-trimester gestation were calculated for progesterone concentrations between 5 and 25 ng/ml.
  
  
  RESULTS
  Receiver-operator characteristic curve analysis indicated that the best discriminatory progesterone concentration was 10 ng/ml. Test efficiency was maximum between serum progesterone concentration of 9 to 14 ng/ml (80%). When progesterone was less than 10 ng/ml, the predictive value of the abnormal test result was greater than 90%.
  
  
  CONCLUSIONS
  Receiver-operator characteristic analysis, test efficiency, and the predictive value of an abnormal test result suggest that the best progesterone cut off point that predicts abnormal early pregnancies is 10 ng/ml.
authors.affiliation: Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson 39216-4505.
authors.forename: B D
authors.initials: BD
authors.lastname: Cowan
authors.forename: D T
authors.initials: DT
authors.lastname: Vandermolen
authors.forename: C A
authors.initials: CA
authors.lastname: Long
authors.forename: N S
authors.initials: NS
authors.lastname: Whitworth
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood / Q000175:diagnosis*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D009994:Osmolar Concentration; D011237:Predictive Value of Tests; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000097:blood / Q000175:diagnosis*; D011374:Progesterone / Q000097:blood*; D012372:ROC Curve; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D011374:Progesterone