Accuracy of salivary estriol testing compared to traditional risk factor assessment in predicting preterm birth

OBJECTIVE: The objective was to compare the predictive accuracy (percentage of correct vs incorrect predictions) of salivary estriol levels (SalEst; B iex, Inc, Dublin, Calif) with that of the modified Creasy score for predict ing preterm labor followed by preterm delivery. STUDY DESIGN: A triple-blinded prospective trial was conducted at 8 US cent ers. RESULTS: Among 601 evaluable patients, serial salivary estriol testing corr ectly predicted the appropriate outcome 91% of the time and the Creasy scor ing method correctly predicted the appropriate outcome 75% of the time (McN emar test P <.001). Among subjects with Creasy scores greater than or equal to 10 thigh-risk group. n = 152), use of salivary estriol testing correctl y predicted the end point 87% of the time, compared with only 7.2% correctl y predicted by modified Creasy scoring (McNemar test P <.001). CONCLUSION: Salivary estriol assessment was more accurate in predicting out come than was modified Creasy scoring.