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1.
Summary.  Alongside the development of meta-analysis as a tool for summarizing research literature, there is renewed interest in broader forms of quantitative synthesis that are aimed at combining evidence from different study designs or evidence on multiple parameters. These have been proposed under various headings: the confidence profile method, cross-design synthesis, hierarchical models and generalized evidence synthesis. Models that are used in health technology assessment are also referred to as representing a synthesis of evidence in a mathematical structure. Here we review alternative approaches to statistical evidence synthesis, and their implications for epidemiology and medical decision-making. The methods include hierarchical models, models informed by evidence on different functions of several parameters and models incorporating both of these features. The need to check for consistency of evidence when using these powerful methods is emphasized. We develop a rationale for evidence synthesis that is based on Bayesian decision modelling and expected value of information theory, which stresses not only the need for a lack of bias in estimates of treatment effects but also a lack of bias in assessments of uncertainty. The increasing reliance of governmental bodies like the UK National Institute for Clinical Excellence on complex evidence synthesis in decision modelling is discussed.  相似文献   
2.
以教育部2002年颁布的《全国普通高等学校体育课程指导纲要》为基础,结合多年的体育教学经验,对我国普通高校体育改革的综合化发展趋势的相关理论进行了探索与研究,并阐述了体育竟争与创新的综合化、体育目标和功能的综合化、体育技术和手段的综合化、体育场馆管理的综合化等理论。为我国普通高校体育教学与发展提供有益的参考依据。  相似文献   
3.
合成了两种新型兼有植物生长调节剂和除草剂功效的N硝基 -N -氨基 (取代 )甲酰 - 2 ,4 ,6 -三氯苯氨类化合物 ,并经元素分析、红外光谱等证实了它们的结构 .  相似文献   
4.
在硫酸铁铵的催化下 ,利用高压微波技术 ,快速合成了肉桂酸甲酯。最佳反应条件为 :甲醇和肉桂酸的摩尔比为 5 :1,催化剂用量为 2 .0g ,微波时间为 3min ,微波功率为 72 9W ,产率达93.8%。  相似文献   
5.
以正交实验法对硫酸盐镀锌光亮剂高温载体GZL-02的合成工艺条件进行了优化研究,并对其表面化学性能和电镀性能进行了测定.最佳合成工艺条件为,聚醚∶顺酐=1∶1.05(摩尔比),酯化温度75℃,时间2h.最终产物得率超过97%.  相似文献   
6.
在阐明可持续发展基本理论的基础上,根据省情,从经济、社会、资源、环境四方面构建湖北省可持续发展指标体系,针对小样本数据特点,运用灰色关联分析法、偏最小二乘回归对其可持续发展状况进行动态评价。  相似文献   
7.
通过酰氯与胺的作用合成了配体N,N,N′,N′-四〔2-(2-吡啶基)乙基〕(o,m,p)苯二甲酰胺.该配体和铜(Ⅱ)配合,合成了三种新配合物,并以红外光谱、电子光谱、摩尔电导率、元素分析及核磁共振谱进行了表征.  相似文献   
8.
空间光通信ATP系统设计分析   总被引:2,自引:0,他引:2  
空间光束捕获、跟踪、瞄准(ATP)技术在空间光通信中具有重要地位。文中讨论了空间光通信系统中的ATP伺服系统的结构,并对系统稳态设计和系统动态综合等关键问题进行了详细的分析和研究。  相似文献   
9.
Logic models (LMs) have been used in programme evaluation for over four decades. Current debate questions the ability of logic modelling techniques to incorporate contextual factors into logic models. We share experience of developing a logic model within an ongoing realist evaluation which assesses the extent to which, and under what circumstances a community health workers (CHW) programme promotes access to maternity services in Nigeria. The article contributes to logic modelling debate by: i) reflecting on how other scholars captured context during LM development in theory-driven evaluations; and ii) explaining how we explored context during logic model development for realist evaluation of the CHW programme in Nigeria. Data collection methods that informed our logic model development included documents review, email discussions and teleconferences with programme stakeholders and a technical workshop with researchers to clarify programme goals and untangle relationships among programme elements. One of the most important findings is that, rather than being an end in itself, logic model development is an essential step for identifying initial hypotheses for tentative relevant contexts, mechanisms and outcomes (CMOs) and CMO configurations of how programmes produce change. The logic model also informed development of a methodology handbook that is guiding verification and consolidation of underlying programme theories.  相似文献   
10.
The complex ways in which food security actions lead to nutrition and other health outcomes make it important to clarify what programs work and how, with theory-driven evaluation emerging as a promising approach to evaluate complex programs. However, it is unclear how and why theory-driven evaluation is applied in food security contexts. Our objective is to examine the development and use of Theory of Change and Realist Evaluation to support food security programs globally. Using a systematic search and screening process, we included studies that described a food security program, used a Theory of Change or Realist Evaluation, and presented original research or evaluations. We found a total of 59 relevant Theory of Change studies and eight Realist Evaluation studies. Based on our analysis, Theories of Change arose in response to three main problems: 1) the need to evaluate under complexity; 2) challenges with evaluation; and, 3) information gaps surrounding a program. In contrast, Realist Evaluation was reported to be developed primarily to understand a program’s outcomes. Reflecting on the problem to be addressed in the evaluation would help improve understandings of the evaluation context, which would then inform the choice and design of an evaluation approach.  相似文献   
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