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81.
Several researchers have proposed solutions to control type I error rate in sequential designs. The use of Bayesian sequential design becomes more common; however, these designs are subject to inflation of the type I error rate. We propose a Bayesian sequential design for binary outcome using an alpha‐spending function to control the overall type I error rate. Algorithms are presented for calculating critical values and power for the proposed designs. We also propose a new stopping rule for futility. Sensitivity analysis is implemented for assessing the effects of varying the parameters of the prior distribution and maximum total sample size on critical values. Alpha‐spending functions are compared using power and actual sample size through simulations. Further simulations show that, when total sample size is fixed, the proposed design has greater power than the traditional Bayesian sequential design, which sets equal stopping bounds at all interim analyses. We also find that the proposed design with the new stopping for futility rule results in greater power and can stop earlier with a smaller actual sample size, compared with the traditional stopping rule for futility when all other conditions are held constant. Finally, we apply the proposed method to a real data set and compare the results with traditional designs.  相似文献   
82.
Patient heterogeneity may complicate dose‐finding in phase 1 clinical trials if the dose‐toxicity curves differ between subgroups. Conducting separate trials within subgroups may lead to infeasibly small sample sizes in subgroups having low prevalence. Alternatively,it is not obvious how to conduct a single trial while accounting for heterogeneity. To address this problem,we consider a generalization of the continual reassessment method on the basis of a hierarchical Bayesian dose‐toxicity model that borrows strength between subgroups under the assumption that the subgroups are exchangeable. We evaluate a design using this model that includes subgroup‐specific dose selection and safety rules. A simulation study is presented that includes comparison of this method to 3 alternative approaches,on the basis of nonhierarchical models,that make different types of assumptions about within‐subgroup dose‐toxicity curves. The simulations show that the hierarchical model‐based method is recommended in settings where the dose‐toxicity curves are exchangeable between subgroups. We present practical guidelines for application and provide computer programs for trial simulation and conduct.  相似文献   
83.
王鹏 《社会》2017,37(5):217-241
随着中国城镇化进程的推进,越来越多的农村户籍人口实现了身份转换,成为制度认可的新市民。本文利用中国综合社会调查(CGSS)数据发现,即使户口状况相同,"新市民"与"老市民"之间依然存在一定的收入差距。分位数回归及其分解的结果显示,"农转非"人群在劳动力市场上仍受到制度性或非制度性歧视,且歧视程度随着分位数的变化呈现倒U型趋势。同时,"农转非"人群内部也存在较大的差异,歧视降低了自致型"农转非"人群相较于城市原居民的禀赋优势,而外致型"农转非"人群则面临人力资本劣势与就业市场歧视的双重压力。  相似文献   
84.
Mixed methods were applied to examine the association of community participation by disabled youth with socioeconomic factors in rural Sri Lanka. There was a significant association between community participation and socioeconomic factors in the quantitative survey (n = 116): participants living in socioeconomically disadvantaged conditions had lower levels of community participation than those living without these disadvantages. Consistent with the findings of the survey, previous educational experiences, household economic conditions, and perceived resource information were common themes in the qualitative study (n = 26). The dynamics of these factors, including marginalisation of disabled youth within the household, were also observed.  相似文献   
85.
ABSTRACT

Recent studies have begun to attend to distribution of household labor within same-gender couples compared to heterosexual couples, yet much of the available research with lesbian couples has attempted to superimpose division of household labor frameworks developed with heterosexual couples (e.g., gender role socialization, exchange bargaining theories) to fit the experiences of same-gender couples. Using two academic search databases, the present article provides a systematic review of the available 28 peer-reviewed articles published from 2000–2015 about lesbian partnerships and household labor divisions. Results indicate that lesbian couples engage in a more equal distribution of household labor than heterosexual couples, and that lesbian women often opt to eschew traditional gendered divisions of chores in favor of other factors such as quality of task or ability. The systematic review uncovered notable constraints in the demography of participants (e.g., race, socioeconomic status, geographic location) across studies. Strategies for deepening the depth and breadth of this line of work for future researchers, and implications for relationship satisfaction are also discussed.  相似文献   
86.

Background

Childbirth fear is the most common underlying reason for requesting a caesarean section without medical reason. The aim of this randomised controlled study was to investigate birth preferences in women undergoing treatment for childbirth fear, and to investigate birth experience and satisfaction with the allocated treatment.

Methods

Pregnant women classified with childbirth fear (≥60 on the Fear Of Birth Scale) (n = 258) were recruited at one university hospital and two regional hospitals over one year. The participants were randomised (1:1) to intervention (Internet-based Cognitive Behaviour Therapy (ICBT)) (n = 127) or standard care (face-to-face counselling) (n = 131). Data were collected by questionnaires in pregnancy week 20–25 (baseline), week 36 and two months after birth.

Results

Caesarean section preference decreased from 34% to 12% in the ICBT group and from 24% to 20% in the counselling group. Two months after birth, the preference for caesarean increased to 20% in the ICBT group and to 29% in the counselling group, and there was no statistically significant change over time. Women in the ICBT group were less satisfied with the treatment (OR 4.5). The treatment had no impact on or worsened their childbirth fear (OR 5.5). There were no differences between the groups regarding birth experience.

Conclusion

Women’s birth preferences fluctuated over the course of pregnancy and after birth regardless of treatment method. Women felt their fear was reduced and were more satisfied with face-to-face counselling compared to ICBT. A higher percentage were lost to follow-up in ICBT group suggesting a need for further research.  相似文献   
87.
农村劳动力向非农产业和城镇转移是提高农业商品化水平的必然要求。本文使用近期的农户调研数据考察了家庭成员外出务工对农户农业商品化率的影响。计量分析表明,从整体上看,务工户与非务工户之间的农业商品率不存在显著差异。我们将农业生产按要素密集程度进行划分后,才发现成员外出务工所带来的潜在影响,务工户粮食生产的商品化率有了提高,而其它农业生产的商品化率则显著下降了。此外,我们还发现,农地市场及农村信贷市场发育对农户农业商品化发展具有重要作用。  相似文献   
88.
This paper asks whether maternal employment has a lasting influence on the division of household labor for married women and men. Employing multi-level models with 2002 ISSP survey data for 31 countries, we test the lagged accommodation hypothesis that a long societal history of maternal employment contributes to more egalitarian household arrangements. Our results find that living in a country with a legacy of high maternal employment is positively associated with housework task-sharing, even controlling for the personal socialization experience of growing up with a mother who worked for pay. In formerly socialist countries, however, there is less gender parity in housework than predicted by the high historical level of maternal employment.  相似文献   
89.
现代中国的农村土地制度进行了三次伟大变革,其基本成果就是现行农村土地制度;这一制度关系国之根本并具有其基本合理性,但也存在某些严重缺陷,应当以高度慎重的态度进行渐进式的改革完善。城乡二元体制是造成农村土地制度严重缺陷的首要根源,应当坚决摒弃。  相似文献   
90.
与诉讼契约有所不同,审理契约之主体范围突破了双方当事人的限制,涵盖了法院。于审理构造而言,审理契约最为重要的就是两造与法官所达成的关于审理计划和争点决定的合意。就诉讼契约的成立与撤回要件、形式、内容及效果等也因种类不同而各异。在协动主义的审理模式下,认可审理契约不仅有助于实现口头辩论的集中化,而且有助于提高审理的计划性,促进审理的高效运营。  相似文献   
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