Properties of the weighted log‐rank test in the design of confirmatory studies with delayed effects

Proportional hazards are a common assumption when designing confirmatory clinical trials in oncology. This assumption not only affects the analysis part but also the sample size calculation. The presence of delayed effects causes a change in the hazard ratio while the trial is ongoing since at the beginning we do not observe any difference between treatment arms, and after some unknown time point, the differences between treatment arms will start to appear. Hence, the proportional hazards assumption no longer holds, and both sample size calculation and analysis methods to be used should be reconsidered. The weighted log‐rank test allows a weighting for early, middle, and late differences through the Fleming and Harrington class of weights and is proven to be more efficient when the proportional hazards assumption does not hold. The Fleming and Harrington class of weights, along with the estimated delay, can be incorporated into the sample size calculation in order to maintain the desired power once the treatment arm differences start to appear. In this article, we explore the impact of delayed effects in group sequential and adaptive group sequential designs and make an empirical evaluation in terms of power and type‐I error rate of the of the weighted log‐rank test in a simulated scenario with fixed values of the Fleming and Harrington class of weights. We also give some practical recommendations regarding which methodology should be used in the presence of delayed effects depending on certain characteristics of the trial.     

Influences on registered nurses' decision‐making in cases of suspected child abuse

This paper reports on the factors influencing decision‐making for a group of 10 South Australian community nurses in cases of suspected child abuse. Each nurse participated in a structured interview. The data were organized into themes, using the computer program NUD*IST. Factors having an impact on the nurses' decisions to report included: the type of suspected abuse, making moral judgements and decision‐making, the consequences of reporting, and the impact versus the outcomes of reporting. Most significantly, the community nurses based many of their decisions on their estimation of the kind of intervention likely to be undertaken by children's protection services. Copyright © 2002 John Wiley & Sons, Ltd.     

论新闻报道策划的实践意义

新闻报道策划 在近几年的新闻实践中应用非常广泛。就报道主题、整合信息、沟通受众和发挥媒体整体优 势等方面论述了新闻报道策划的实践意义。     

对分部信息披露制度的认识

为了规范分部信息的披露行为 ,各国会计准则制定机构、证券管理部门以及有关国际组织 ,纷纷发布准则或制度 ,对分部信息披露的要求作出规定 ,形成了各自的分部信息披露制度。本文在借鉴了各国分部信息披露制度的基础上 ,指出了我国分部信息披露制度存在的问题 ,并提出了一些改进建议。     

论电视现场报道的特色与创新

电视现场报道是社会人群求新求真和认识多元化的产物。现今的电视现场报道可以概括为三种形式 :主体式报道、客体式报道和主客体交融式报道。在此基础上的电视现场报道的发展和创新应该是新闻故事化和故事情节化、创造性地运用蒙太奇手段、正确过程画面和声音细节 ,并尽可能做到一个时空展现一个事件     

深度报道:历史性契约

关于“深度报道”的各种思考充斥于新闻传播学领域,遗憾的是,诸多的讨论却由于本体思考的缺失或倒错,最终偏离了期望的轨道,反造成知识上的混乱。究其实,“深度报道”是人类规避简单思维求取生存真相的一种努力。它一头扎进复杂的现实背景中去,该背景深入到事实的每一个原子中去,以至于特别的偏好事实的模糊性。它所追寻的是历史记忆的官能,它所采纳的是社会学的思考,它所贡献的是强烈的批判性。它是人类在“极速主义”时代求取清明的一种负责任的大努力。     

Pharmacovigilance in Clinical Trials: Current Practice and Challenges

In view of the MENA increasing participation in multinational trials and the increasing number of national/regional trials, this article explores potential areas of pharmacovigilance, requiring reform and provides recommendations for building a robust safety reporting system. Regulatory silence on expedited reporting requirements creates confusion for local sites that are part of multinational trials. Not allowing waiver for serious adverse events that are protocol specified or are study endpoints, along with lack of emphasis on causality as reporting criteria, adds substantial burden of uninformative cases for regulatory review. Despite global focus on Development Safety Update Report, local regulators are not yet insistent on real-time update of a drug’s cumulative safety profile. Issues like reporting requirements for generic trials, pregnancy reporting and lenient timeline for death/life-threatening events need attention. Finally, the need to formulate an all-encompassing local pharmacovigilance guideline, in sync with global practice cannot be overemphasized.     

Dividend barrier and ruin problems for a risk model with delayed claims

In this paper, a compound Poisson risk model in the presence of a constant dividend barrier is considered. Two types of individual claims, main claims and by-claims, are defined, where every by-claim is induced by the main claim and and the time of delay for the claim is assumed to be random. A system of integro-differential equations with certain boundary conditions for the expected discounted penalty function is derived. We show that its solution can be expressed as the solution to the expected discounted penalty function in the same risk model with the absence of a barrier plus a linear combination of two linearly independent solutions to the associated homogeneous integro-differential equation. Using systems of integro-differential equations for the moment-generating function as well as for the arbitrary moments of the sum of discounted dividend payments until ruin, a matrix version of the dividends–penalty type relationship is derived. We also prove that ruin is certain under constant dividend barrier strategy. The closed form expressions are given when the claim amounts from both classes are exponentially distributed. Finally, a numerical example is presented to illustrate the solution procedure.     

Using a participatory evaluation design to create an online data collection and monitoring system for New Mexico's Community Health Councils

We present the collaborative development of a web-based data collection and monitoring plan for thirty-two county councils within New Mexico's health council system. The monitoring plan, a key component in our multiyear participatory statewide evaluation process, was co-developed with the end users: representatives of the health councils. Guided by the Institute of Medicine's Community, Health Improvement Process framework, we first developed a logic model that delineated processes and intermediate systems-level outcomes in council development, planning, and community action. Through the online system, health councils reported data on intermediate outcomes, including policy changes and funds leveraged. The system captured data that were common across the health council system, yet was also flexible so that councils could report their unique accomplishments at the county level. A main benefit of the online system was that it provided the ability to assess intermediate, outcomes across the health council system. Developing the system was not without challenges, including creating processes to ensure participation across a large rural state; creating shared understanding of intermediate outcomes and indicators; and overcoming technological issues. Even through the challenges, however, the benefits of committing to using participatory processes far outweighed the challenges.