OBJECTIVE To estimate whether length of the first stage of labor is associated with adverse maternal and neonatal outcomes. METHODS This is a retrospective cohort study of nulliparous women with term, singleton gestations delivered in one academic center between 1990 and 2008. The length of the first stage was stratified into three subgroups: less than the 5th percentile, 5th to 95th percenti...

Obesity is an established risk factor for non-insulin-dependent diabetes mellitus (NIDDM). Anthropometric measures of overall and central obesity as predictors of NIDDM risk have not been as well studied, especially in women. Among 43,581 women enrolled in the Nurses' Health Study who in 1986 provided waist, hip, and weight information and who were initially free from diabetes and other major c...

Descriptive statistics include measures of central tendency and variability. Measures of central tendency include mean, median, and mode. The mean is the arithmetic average of data from interval or ratio scales. The median reflects the 50th percentile score. The mode is the most frequently occurring value of a data distribution. Measures of variability include range, interquartile range, standa...

Cross-validation based point estimates of prediction accuracy are frequently reported in microarray class prediction problems. However these point estimates can be highly variable, particularly for small sample numbers, and it would be useful to provide confidence intervals of prediction accuracy. We performed an extensive study of existing confidence interval methods and compared their perform...

OBJECTIVES To explore the effect of aging on cardiac toxicity specifically the interaction of age and antipsychotic drugs to alter the QT interval. METHODS THE MEDLINE DATABASES WERE SEARCHED USING THE OVIDSP PLATFORMS WITH THE SEARCH STRATEGY: "QT interval" or "QT" and "age" or "aging". The entry criteria were: over 10,000 apparently healthy individuals with data on both sexes; QT interval c...

The asymptotic formula for the variance of a percentile estimate is inversely proportional to the square of the probability density function evaluated at that percentile. In this note we show, for small and moderate sample sizes, that the estimate of the variance can have a moderate to large coefficient of variation even when the form of the density is known. When the density must be estimated ...

Construction of simultaneous confidence bands for a percentile line in linear regression has been considered by several authors. But only conservative symmetric bands, which use critical constants over the whole covariate range (−∞, ∞), are available in the literature. New methods allow the construction of exact symmetric bands for a percentile line over a finite interval of the covariate x. Th...

Abstract In this paper, optimization of acceptance interval in conformity assessment using the expression revenue that we showed part 1 study is proposed under condition a systematic effect component being present measurement uncertainty. Systematic components are caused by unknown biases. Using distribution based on uncertainty information bias, can develop revenue. Our idea to set percentile ...

OBJECTIVES Childhood obesity continues to be a problem. Children in rural populations are more likely to be overweight or obese and a lack of resources in those areas may contribute to this problem. We aimed to assess the impact of a pilot pharmacy health-care professional out-of-school time vigorous physical activity and nutrition education program on fourth and fifth graders in a rural Texas ...