In most clinical and experimental studies, the standard deviation (SD) and the estimated standard error of the mean (SEM) are used to present the characteristics of sample data and to explain statistical analysis results. However, some authors occasionally muddle the distinctive usage between the SD and SEM in medical literature. Because the process of calculating the SD and SEM includes differ...

As a nonstatistician, I have watched the discussion on this topic with interest (1–8). Dr. Curren-Everett and others make a clear statement that variability of results should always be reported using the standard deviation (SD) and not the standard error (SE). Others cited above variously agree and disagree with the guidelines published by Dr. Curren-Everett and others. The reasoning provided i...

In the two Higgs-doublet SM, perturbativity breaks down below Λ P lanck : For m top = 170 − 180 GeV, g top reaches the pole at scales below 1000 TeV if the ratio of vev's v u /v d is smaller than 1. We discuss top condensate scenarios assuming 150 GeV ≤ m top ≤ 200 GeV: The phenomenological work of the last years shows a version with two composite Higgs doublets as a viable option. In the theor...

The potential for bias due to misclassification error in regression analysis is well understood by statisticians and epidemiologists. Assuming little or no available data for estimating misclassification probabilities, investigators sometimes seek to gauge the sensitivity of an estimated effect to variations in the assumed values of those probabilities. We present an intuitive and flexible appr...

INTRODUCTION The National Hospital Discharge Survey is a primary data source for epidemiology research in the United States. To ensure that estimates are reliable, confidence intervals need to be calculated. The original survey data source is not available to the public, and the usual statistical methods are unsuitable for calculating confidence intervals. Instead, calculating confidence interv...

Background: To describe factors contributed to the maternal deaths occurred in the West Azerbaijan, Iran from 2002 through 2011. Materials and Methods: In a cross-sectional study, data on the maternal deaths obtained from the national maternal mortality surveillance system were analyzed. The three delays model was used so as to recognize contributing factors of maternal deaths due to obstetric ...

SIMEX is a general-purpose technique for measurement error correction. There is a substantial literature on the application and theory of SIMEX for purely parametric problems, as well as for purely non-parametric regression problems, but there is neither application nor theory for semiparametric problems. Motivated by an example involving radiation dosimetry, we develop the basic theory for SIM...

CONTEXT Two-dimensional (2D) video analysis of frontal-plane dynamic knee valgus during common athletic screening tasks has been purported to identify individuals who may be at high risk of suffering knee injuries such as anterior cruciate ligament tear or patellofemoral pain syndrome. Although the validity of 2D video analysis has been studied, the associated reliability and measurement error ...