RESUMO
Objective To investigate the relationship between the optimal cutoff point of serum homocyste-ine(Hcy)and premature delivery in pregnant women ,and to analyze the influence of Hcy levels on the outcome of preterm infants. Methods Totally 114 cases of pregnant women were chosen as observation group and 103 cases of normal as control group. Hcy,D-D and hypersensitive C reactive protein were detected;analysis of the ROC curve was conducted by using the SPSS 13 software and the risk factors for preterm delivery were analyzed using logistic multivariate regression analysis. Results (1)The levels of Hcy,HS-CRP and D-D in preterm pregnant women were higher than those in control group and the difference was statistically significant (P < 0.05). (2) Logistic regression analysis showed that the relative risk coefficient(OR)of Hcy was 9.736,and the regression equation of premature birth probability was obtained.(3)ROC curve to evaluate the predictive value of Hcy in risk factors of preterm birth was 0.931;when Hcy was 13.8μmol/L,the Youden index was 0.784.(4)Elevated levels of Hcy in preterm women led to a marked increase in the likelihood of SGA. Conclusion When predicting risk factors for preterm birth,the best predictive cutoff value for Hcy is 13.8μmol/L,which is one of the independent risk factors for preterm birth.
RESUMO
Objective To investigate the relationship between the optimal cutoff point of serum homocyste-ine(Hcy)and premature delivery in pregnant women ,and to analyze the influence of Hcy levels on the outcome of preterm infants. Methods Totally 114 cases of pregnant women were chosen as observation group and 103 cases of normal as control group. Hcy,D-D and hypersensitive C reactive protein were detected;analysis of the ROC curve was conducted by using the SPSS 13 software and the risk factors for preterm delivery were analyzed using logistic multivariate regression analysis. Results (1)The levels of Hcy,HS-CRP and D-D in preterm pregnant women were higher than those in control group and the difference was statistically significant (P < 0.05). (2) Logistic regression analysis showed that the relative risk coefficient(OR)of Hcy was 9.736,and the regression equation of premature birth probability was obtained.(3)ROC curve to evaluate the predictive value of Hcy in risk factors of preterm birth was 0.931;when Hcy was 13.8μmol/L,the Youden index was 0.784.(4)Elevated levels of Hcy in preterm women led to a marked increase in the likelihood of SGA. Conclusion When predicting risk factors for preterm birth,the best predictive cutoff value for Hcy is 13.8μmol/L,which is one of the independent risk factors for preterm birth.
RESUMO
Sensitivity and specificity are two components that measure the inherent validity of a diagnostic test for dichotomous outcomes against a gold standard. Receiver operating characteristic (ROC) curve is the plot that depicts the trade-off between the sensitivity and (1-specificity) across a series of cut-off points when the diagnostic test is continuous or on ordinal scale (minimum 5 categories). This is an effective method for assessing the performance of a diagnostic test. The aim of this article is to provide basic conceptual framework and interpretation of ROC analysis to help medical researchers to use it effectively. ROC curve and its important components like area under the curve, sensitivity at specified specificity and vice versa, and partial area under the curve are discussed. Various other issues such as choice between parametric and non-parametric methods, biases that affect the performance of a diagnostic test, sample size for estimating the sensitivity, specificity, and area under ROC curve, and details of commonly used softwares in ROC analysis are also presented.