In this paper, a new sampling procedure is presented for three-way stratification when one of the stratifying variables is time. The purpose of such a design is to take into account serial correlation. The variance of the unweighted estimator of the population mean with respect to a super ...
Many of the variables under consideration are statistically related to thestratifyingvariables. From theCambridge English Corpus Our approach is more open and focuses on thestratifyingeffects of conditions of eligibility and benefit levels. From theCambridge English Corpus They described a wide-field, dif...
Still, the change in CPC counts during exercise remained significantly associated with adverse events (HR 2.59; 95%CI 1.15-5.32 per 50% CD34+/CXCR4+ count decrease) even after adjustment for clinical variables and the presence of ischemia. The researchers were better able to discriminate risk fa...
For model creation, 41 candidate predictor variables were measured and after composite variable creation, 21 variables remained. Of these, eight important predictors were identified to formulate the 4C Mortality Score: age, sex, number of comorbidities, respiratory rate, peripheral oxygen saturation, Gla...
Data are expressed as mean ± SD for continuous variables, median and range for categorical variables, respectively. Statistical significance level of α = 0.05 was set before experiments. All statistical tests were two-sided if not noted otherwise. For correlation analysis, a Pearson produ...
They were also confirmed by the univariable analysis between the continuous variables and overall survival using restricted cubic splines in eFigure 2 in Supplement 1. Overall survival was calculated from the date of surgery to that of death (by any cause) or the last follow-up. Cancer-specific...
Table 4. Univariable Association for MACE and Death: CMR Variables CMR Potential PredictorsMACEDeath HR (95% CI)p ValueHR (95% CI)p Value LVEF, % 0.95 (0.94–0.97) <0.001 0.96 (0.94–0.98) <0.001 LVEF <40% 3.91 (2.07–7.38) <0.001 4.0 (2.95–5.44) <0.001 LVEDVi, ml/m2 1.01 (1....
OPTIMUM STRATIFICATION BY TWO STRATIFYING VARIABLES USING MATHEMATICAL PROGRAMMINGDanish, FaizanRizvi, S. E. H.Pakistan Journal of Statistics
In this paper, we study the effect of using two independent stratifying variables on the approximate value of the variance of the stratified sample mean obtained by Al-Kassab and Al-Elemat [1]. Ten special cases are obtained and a comparison between these special cases is given using four ...
On the Effect of Stratification When the Two Stratifying Variables Having Bivariate Normal DistributionMowafaq Al Kassab