Choice of the primary analysis in longitudinal clinical trials

Missing data, and the bias they can cause, are an almost ever‐present concern in clinical trials. The last observation carried forward (LOCF) approach has been frequently utilized to handle missing data in clinical trials, and is often specified in conjunction with analysis of variance (LOCF ANOVA) for the primary analysis. Considerable advances in statistical methodology, and in our ability to implement these methods, have been made in recent years. Likelihood‐based, mixed‐effects model approaches implemented under the missing at random (MAR) framework are now easy to implement, and are commonly used to analyse clinical trial data. Furthermore, such approaches are more robust to the biases from missing data, and provide better control of Type I and Type II errors than LOCF ANOVA. Empirical research and analytic proof have demonstrated that the behaviour of LOCF is uncertain, and in many situations it has not been conservative. Using LOCF as a composite measure of safety, tolerability and efficacy can lead to erroneous conclusions regarding the effectiveness of a drug. This approach also violates the fundamental basis of statistics as it involves testing an outcome that is not a physical parameter of the population, but rather a quantity that can be influenced by investigator behaviour, trial design, etc. Practice should shift away from using LOCF ANOVA as the primary analysis and focus on likelihood‐based, mixed‐effects model approaches developed under the MAR framework, with missing not at random methods used to assess robustness of the primary analysis. Copyright © 2004 John Wiley & Sons, Ltd.     

宗申集团核心竞争力创新模式比较研究

在市场竞争日益激烈的今天,企业核心竞争力的培育无疑成为众多企业关注的焦点。本文运用比较分析方法论述了宗申集团的核心竞争力创新模式。在借鉴与分析海尔集团核心竞争力的基础上,对宗申集团的创新模式提出了几点建议。     

高校全程就业指导模式构建研究

目前高校就业指导现状已不适应高等教育和社会发展的需要。本文以心理测量指导、职业生涯设计指导、学业指导、择业指导、创业指导、升学指导六大指导为主线建构全程化的就业指导模式,全程就业指导就是从大学一年级开始,根据职业指导理论和大学生发展阶段,对大学生分年级、分阶段,结合学生共性与个性,提供全程化就业指导,以实现双向选择、人职匹配和职业目标。     

Creating a reference to a complex emergency situation using time series methods: war in Guinea-Bissau 1998-1999

Impacts of complex emergencies or relief interventions have often been evaluated by absolute mortality compared to international standardized mortality rates. A better evaluation would be to compare with local baseline mortality of the affected populations. A projection of population-based survival data into time of emergency or intervention based on information from before the emergency may create a local baseline reference. We find a log-transformed Gaussian time series model where standard errors of the estimated rates are included in the variance to have the best forecasting capacity. However, if time-at-risk during the forecasted period is known then forecasting might be done using a Poisson time series model with overdispersion. Whatever, the standard error of the estimated rates must be included in the variance of the model either in an additive form in a Gaussian model or in a multiplicative form by overdispersion in a Poisson model. Data on which the forecasting is based must be modelled carefully concerning not only calendar-time trends but also periods with excessive frequency of events (epidemics) and seasonal variations to eliminate residual autocorrelation and to make a proper reference for comparison, reflecting changes over time during the emergency. Hence, when modelled properly it is possible to predict a reference to an emergency-affected population based on local conditions. We predicted childhood mortality during the war in Guinea-Bissau 1998-1999. We found an increased mortality in the first half-year of the war and a mortality corresponding to the expected one in the last half-year of the war.     

应用型本科机械设计制造及自动化专业人才培养方案研究

本文针对应用型本科机械设计制造及其自动化专业如何培养当今社会急缺的高技能复合型人才问题作了探索与研究,提出了新的课程体系与培养方案。     

和谐社会的构建和思维方式

构建和谐社会离不开思维方式的引领。思维方式没有对错之分,却有优劣之别。“向古看”的思维方式不可取。作为马克思主义者应具备的最基础性的思维方式,乃是从实际出发,实事求是,与时俱进。对于引领和谐社会的构建来说,最优的思维方式是带有世界观、方法论意义的以人为本的科学发展观。这是由它自身的起点高、视野宽、思路活的特点,以及构成它的以人为本的理念、现代整体论理念、可持续发展理念三个组成部分的优点所决定的。     

北京市公交系统两种运行模式的比较研究

本文认为，与北京市目前的公交系统运行模式相比，双层“网络＋环形”的运行模式是一种新型高效、有可持续发展功能的公交系统运行模式。主要表现在：贯通型公交网络与环形的结合既能提高公交的机动性，又能提高其可迭性；单线路公交车安排和“枢纽一枢纽”型综合换乘方式都比旧的模式更能提高公交系统的运行效率。     

柔性化:构筑高校教学管理框架的新模式

人类管理活动正在从刚性管理向柔性管理转移 ,柔性化的管理理念对高等学校教学管理同样具有深刻的意义。本文尝试性地阐述柔性化管理对高等学校教学管理框架构筑的适用性 ,以期对高等教育管理者提供一个考虑问题的新方法     

大规模定制生产的业务流程浅析

随着经济社会的转型,企业面对着越来越强大的三股力量:客户、竞争、变化。在该三股力量的不断冲击下,企业原有的生产模式———大规模生产逐渐失去竞争优势。在这种情形下,一种新的生产模式,即大规模定制生产应运而生,并且已经在众多领域成为主流的生产模式。针对大规模定制生产的特点,可以产生出一种新的矩阵结构的业务流程,该矩阵结构的业务流程具有充分的柔性,能够很好地支撑大规模定制生产,发挥其竞争优势。     

新课程改革理念下政治课“自主、合作、探究”学习模式初探

新课程提倡“自主、合作、探究”学习。首先论述目前对“自主、合作、探究”学习教学模式存在的误解,然后本人就新课程提倡“自主、合作、探究”学习的理解和实践经验做了简述。