Using support vector machines in predicting and classifying factors affecting preterm delivery

Various statistical methods have been proposed in terms of predicting the outcomes of facing special factors. In the classical approaches, making the probability distribution or known probability density functions is ordinarily necessary to predict the desired outcome. However, most of the times enough information about the probability distribution of studied variables is not available to the researcher in practice. In such circumstances, we need that the predictors function well without knowing the probability distribution or probability density. It means that with the minimum assumptions, we obtain predictors with high precision. Support vector machine [SVM] is a good statistical method of prediction. The aim of this study is to compare two statistical methods, SVM and logistic regression. To that end, the data on premature infants born at Tehran Milad Hospital is collected and used

Comparison of the therapeutic efficacy of cimetidine and cryotherapy with placebo and cryotherapy in treatment of warts

To compare the therapeutic efficacy of cimetidine and cryotherapy versus placebo and cryotherapy for treatment of warts. This randomized, double-blind clinical trial was conducted on subjects with warts between 2008 and 2009. Exclusion criteria of this study were Raynaud's phenomenon, peripheral vascular disease, previous wart treatment and cold urticaria. Subjects were randomly allocated in two groups. In the first group cimetidine was administered, 40 mg/kg daily for three months, also, their warts were frozen monthly for three months. In the second group placebo was administered and their warts were frozen monthly for three month. Recurrence and cure rates for each group were recorded and data were statically analyzed. 81 subjects were recruited in this study. The mean cure rate obtained one month after treatment was 77.6% in cimetidine-treated group versus 79.3% in placebo-treated group, and the mean cure rate two month after treatment was 93.2% in cimetidine-treated group and 94.6% in placebo-treated group. The mean recurrence rate one month after treatment was 16% in cimetidine treated group and 15.5% in placebo-treated group, the mean recurrence rate two month after treatment was 22.3% in cimetidine-treated group and 23.3% in placebo-treated group, the mean recurrence rate three month after treatment was 31.7% in cimetidine-treated group and 30.1% in placebo-treated group. This study showed that cimetidine is not more effective than placebo in treatment of warts.

Using ROC surface to predict preterm delivery based on hemoglobin level in the first trimester of pregnancy

Receiver Operating Characteristics [ROC] curves have numerous applications for identifying a cut-off point in diagnostic tests. Nonetheless, given that sometimes two cut-off points have to be specified simultaneously, the ROC curve can be used to identify such points. The Volume under the ROC Surface [VUS] serves as a criterion for the accuracy of diagnostic tests. One of the unfortunate outcomes in pregnancy is pre-term delivery; it has been noted that an increase in the level of hemoglobin in the first trimester of pregnancy could result in preterm delivery in weeks 34 to 37 and that an ongoing hemoglobin increase could result in the delivery of a premature fetus before the 34th week of pregnancy. In this regard, in order to separate three groups of on-time delivery, pre-term delivery and immature delivery two cut-off points have to be identified, simultaneously. A suitable measure to identify such points is the ROC surface. In the current study, the hemoglobin information of the first trimester of pregnancy and delivery time of 623 pregnant ladies referring to Milad Hospital in Tehran in 2009-2010 was obtained. ROC surface was adopted to draw two ideal cut-off points for the first trimester of pregnancy. The optimal points for hemoglobin of the first trimester computed with the ROC surface were 12.54 and 13.2. While a hemoglobin rate less than 12.54 indicated an on-time delivery, a rate between the two cut-off points referred to pre-term delivery and hemoglobin more than 13.2 showed a premature fetus. The three-dimensional ROC surface is a useful tool that can visually summarize the ability of a biological marker to classify individuals between more than two groups