Statistical testing strategies for assessing treatment efficacy and marker accuracy in phase III trials

When a candidate predictive marker is available, but evidence on its predictive ability is not sufficiently reliable, all‐comers trials with marker stratification are frequently conducted. We propose a framework for planning and evaluating prospective testing strategies in confirmatory, phase III marker‐stratified clinical trials based on a natural assumption on heterogeneity of treatment effects across marker‐defined subpopulations, where weak rather than strong control is permitted for multiple population tests. For phase III marker‐stratified trials, it is expected that treatment efficacy is established in a particular patient population, possibly in a marker‐defined subpopulation, and that the marker accuracy is assessed when the marker is used to restrict the indication or labelling of the treatment to a marker‐based subpopulation, ie, assessment of the clinical validity of the marker. In this paper, we develop statistical testing strategies based on criteria that are explicitly designated to the marker assessment, including those examining treatment effects in marker‐negative patients. As existing and developed statistical testing strategies can assert treatment efficacy for either the overall patient population or the marker‐positive subpopulation, we also develop criteria for evaluating the operating characteristics of the statistical testing strategies based on the probabilities of asserting treatment efficacy across marker subpopulations. Numerical evaluations to compare the statistical testing strategies based on the developed criteria are provided.     

腔内电光调制激光系统的混沌模拟

采用数值模拟的方法讨论了带反馈的腔內电光调制激光系统功率输出的分叉和混沌行为,得到了输出功率随控制参数变化的分叉图,和一些定量结果。     

中国早期共产主义者对党建思想的探索

早期共产主义者学习和利用马列主义政党学说的基本原理来解决在中国建立政党的过程中遇到的具体问题,提出为什么要建立政党、如何建立和建设政党等党建根本问题。     

冷战后中国多边首脑外交的特点与动因

冷战后，中国以亚太地区和联合国为中心，开展了积极的多边首脑外交。其具有力度不断加大、内容逐渐多元、外在制度完备、内在缺乏约束等特点。经济全球化、集团化和全球性问题的日益突出，则是中国开展多边首脑外交的重要推动力量。     

小波分析在管理数据处理中的应用

提出了一种基于小波变换的管理数据处理方法，把公司管理上的数据看成一个非平稳的时间序列，利用小渡函数将该时间序列分解到不同的频率通道上，然后将分解后的信号当作近似的平稳时间序列，用一些传统的统计方法进行预测，同时对中国足球彩票若干期的销售量数据进行了处理和预测，并将结果与实际销量以及用传统的AR模型的预测值进行了比较。     

20世纪上半叶制约中国社会发展的决定性因素

20世纪上半叶在以战争与革命为主题的时代背景下 ,外国帝国主义的侵略和俄国十月革命对中国社会发展产生了重大影响。半殖民地半封建的社会形态、错综复杂的阶级结构和阶级关系、2 0世纪中国的两大历史主题等也是制约中国社会发展的重要因素。正是由于对这四个因素的正确认识和准确把握 ,中华民族实现了 2 0世纪上半叶中国社会的巨大变革     

语言问题的理论思索

从功能的角度考察语言的本质 ,是诸多著作理解语言性质的哲学基础。功能论固然看到了语言对于人类社会的决定性作用 ,然而却丝毫未触及语言自身的结构特征和机制。仅从功能的角度认识语言是不够的 ,还必须深入到语言结构内部 ,对语言的特征、机制及结构体系进行多角度观察 ,才能较为完整地揭示语言的本质     

从计算机英语词汇中的隐喻现象谈构词特点

由于计算机和网络的出现,计算机英语词汇日益增多。有些新词汇是通过联想,经历语义变化及隐喻修饰后产生的。更多的计算机英语词汇是通过赋新、缩略、合成等方法构成的。对它们构词的特点进行分析并找出规律,可便于计算机使用者更好地理解词义。     

非统计专业统计学教育刍议

针对非统计专业统计学教育目前存在的问题,阐述了提高对统计学重要性的认识是保证统计教学效果的前提;统计学教学环节的改革是提高教学效果的重要保证;统计教师的业务素质是提高统计教学效果的关键。     

Statistical Distributions of Daily Breathing Rates for Narrow Age Groups of Infants and Children

Children may be more susceptible to toxicity from some environmental chemicals than adults. This susceptibility may occur during narrow age periods (windows), which can last from days to years depending on the toxicant. Breathing rates specific to narrow age periods are useful to assess inhalation dose during suspected windows of susceptibility. Because existing breathing rates used in risk assessment are typically for broad age ranges or are based on data not representative of the population, we derived daily breathing rates for narrow age ranges of children designed to be more representative of the current U.S. children's population. These rates were derived using the metabolic conversion method of Layton (1993) and energy intake data adjusted to represent the U.S. population from a relatively recent dietary survey (CSFII 1994–1996, 1998). We calculated conversion factors more specific to children than those previously used. Both nonnormalized (L/day) and normalized (L/kg-day) breathing rates were derived and found comparable to rates derived using energy estimates that are accurate for the individuals sampled but not representative of the population. Estimates of breathing rate variability within a population can be used with stochastic techniques to characterize the range of risk in the population from inhalation exposures. For each age and age-gender group, we present the mean, standard error of the mean, percentiles (50th, 90th, and 95th), geometric mean, standard deviation, 95th percentile, and best-fit parametric models of the breathing rate distributions. The standard errors characterize uncertainty in the parameter estimate, while the percentiles describe the combined interindividual and intra-individual variability of the sampled population. These breathing rates can be used for risk assessment of subchronic and chronic inhalation exposures of narrow age groups of children.