OBJECTIVE The aim of this study is to assess the efficacy of cervical interleukin-6 (IL-6) compared with cervical length and its association in the prediction of preterm delivery in symptomatic women. STUDY DESIGN Observational prospective study was performed at Hospital Universitario La Fe, Valencia (Spain). SAMPLE 100 women between 24 and 34 weeks gestational age, with threatened preterm ...

Test sensitivity and specificity for the FAMACHA(©) clinical test for anaemia due to haemonchosis have previously been shown to be adequate in differentiating between heavily/less heavily infected sheep, but these properties give no objective guidance for setting the optimum threshold at which anthelmintic treatment should occur. The aim of this work was to use Receiver Operating Characteristic...

There are several criteria for determination of the most appropriate cut-off value in a diagnostic test with continuous results. Mostly based on receiver operating characteristic (ROC) analysis, there are various methods to determine the test cut-off value. The most common criteria are the point on ROC curve where the sensitivity and specificity of the test are equal; the point on the curve wit...

1 AUC Estimation The area under the ROC curve can be approximated using lower rectangles, upper rectangles or by using a linear approximation, as shown in Figure 1. The expressions related to each of these approximations are Al(zA) = M−1 ∑ t=0 (1− M̂Rt)(F̂ARt+1 − F̂ARt) Au(zA) = M−1 ∑ t=0 (1− M̂Rt+1)(F̂ARt+1 − F̂ARt) Am(zA) = M−1 ∑ t=0 (1− M̂Rt + M̂Rt+1 2 )(F̂ARt+1 − F̂ARt). Substituting the estimates fo...

BACKGROUND Breastfeeding self-efficacy can be measured with the Breastfeeding Self-Efficacy Scale-Short Form (BSES-SF). Mothers with low BSES-SF scores stop exclusive breastfeeding prematurely, but specific interventions can prevent that undesirable outcome. Because those interventions can be expensive, often one must decide which mothers will receive them. For that purpose, a cut-off BSES-SF s...

Area under an ROC curve plays an important role in estimating discrimination performance – a well-known theorem by Green (1964) states that ROC area equals the percentage of correct in two-alternative forcedchoice setting. When only single data point is available, the upper and lower bound of discrimination performance can be constructed based on the maximum and minimum area of legitimate ROC c...

BACKGROUND Teenage pregnancy is a known social problem which has been previously described using a number of deprivation measures. This study aimed to explore the temporal patterns of teenage pregnancy in Aberdeen, Scotland and to assess the discriminating ability of three measures of socioeconomic status. METHODS This was a population-based study from 1950 to 2010, using data from the Aberde...

Background: Inflammatory bowel disease (IBD) involves chronic inflammation of the digestive tract. In the past decades, fecal calprotectin has been proposed as a useful biomarker for the differential diagnosis between IBD patients and healthy controls. We designed this study to evaluate the diagnostic ability of fecal calprotectin (FC) and conventional inflammatory markers in IBD patients. M...

BACKGROUND An explanation is offered for the asymmetry of Receiver Operating Characteristic (ROC) curves obtained from pilots' decisions to eject. The curves can be fitted by a Gaussian model with unequal variances; however, that model does not provide a ready interpretation of the shape of the obtained ROCs. HYPOTHESIS In an emergency, a pilot receives information from many parallel sources ...

Advances in technology provide new diagnostic tests for early detection of disease. Frequently, these tests have continuous outcomes. One popular method to summarize the accuracy of such a test is the Receiver Operating Characteristic (ROC) curve. Methods for estimating ROC curves have long been available. To examine covariate effects, Pepe (1997, 2000) and Alonzo and Pepe (2002) proposed distr...