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81.
82.
Phase II clinical trials are performed to investigate whether a novel treatment shows sufficient promise of efficacy to justify its evaluation in a subsequent definitive phase III trial, and they are often also used to select the dose to take forward. In this paper we discuss different design proposals for a phase II trial in which three active treatment doses and a placebo control are to be compared in terms of a single‐ordered categorical endpoint. The sample size requirements for one‐stage and two‐stage designs are derived, based on an approach similar to that of Dunnett. Detailed computations are prepared for an illustrative example concerning a study in stroke. Allowance for early stopping for futility is made. Simulations are used to verify that the specified type I error and power requirements are valid, despite certain approximations used in the derivation of sample size. The advantages and disadvantages of the different designs are discussed, and the scope for extending the approach to different forms of endpoint is considered. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
83.
Robert M. Levy Roman Saikovsky Evgeniya Shmidt Alexander Khokhlov Bruce P. Burnett 《Nutrition Research》2009
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups. 相似文献
84.
Biostatisticians have frequently uncritically accepted the measurements provided by their medical colleagues engaged in clinical research. Such measures often involve considerable loss of information. Particularly, unfortunate is the widespread use of the so‐called ‘responder analysis’, which may involve not only a loss of information through dichotomization, but also extravagant and unjustified causal inference regarding individual treatment effects at the patient level, and, increasingly, the use of the so‐called number needed to treat scale of measurement. Other problems involve inefficient use of baseline measurements, the use of covariates measured after the start of treatment, the interpretation of titrations and composite response measures. Many of these bad practices are becoming enshrined in the regulatory guidance to the pharmaceutical industry. We consider the losses involved in inappropriate measures and suggest that statisticians should pay more attention to this aspect of their work. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
85.
We analyze whether the political system and its stability are related to cross-country differences in health. We apply factor analysis on various national health indicators for a large sample of countries over the period 2000–2005 and use the outcomes of the factor analysis to construct two new health measures, i.e., the health of individuals and the quality of the health care sector. Using a cross-country structural equation model with various economic and demographic control variables, we examine the relationship between the type of regime and political stability on the one hand and health on the other. The political variables and the control variables are measured as averages over the period 1980–1999. Our results suggest that democracy has a positive relationship with the health of individuals, while regime instability has a negative relationship with the health of individuals. Government instability is negatively related to individual health via its link with the quality of the health care sector, while democracy is positively related with individual health through its link with income. Our main findings are confirmed by the results of a panel model and various sensitivity tests. 相似文献
86.
目的探讨碱性成纤维细胞生长因子(bFGF)不同剂量、用药方法对扩张组织的影响.方法以白色家猪为实验动物,采用持续恒压扩张技术,观察不同剂量和不同给药时间,bFGF和硫糖铝对扩张组织的影响及组织结构变化.结果扩张术同时每日2次局部应用bFGF 9AU/cm2 硫糖铝100μg/ml,共7 d,浸于明胶海绵上缓慢持续释放对扩张组织的影响最明显,效果最佳,扩张器内实际注液量、扩张所获得的皮肤净增面积明显增加,皮瓣回缩率降低.表皮细胞层数增多,胶原纤维、弹力纤维、成纤维细胞密度和毛细血管密度显著增高.药量增加效果未随之增加.结论持续恒压扩张术时合用bF-GF 9AU/cm2 硫糖铝100μg/ml,每日2次注药浸入明胶海绵持续缓慢释放效果最佳. 相似文献
87.
碱性成纤维细胞生长因子在实验性硬脑膜重建中的应用 总被引:3,自引:0,他引:3
[目的] 探讨碱性成纤维细胞生长因子( bFGF)在实验性自体筋膜硬脑膜重建中的应用价值.[方法]取 SD大鼠 35只,分成 5组.其中 A组 3只,直接将背部筋膜覆盖在硬膜外, B组 5只,采用自体筋膜硬脑膜重建模型,通过免疫组织化学方法观察这两组大鼠自体筋膜硬脑膜移植的愈合过程及细胞因子 bFGF在其中的表达; C组、 D组、 E组各 9只,分别进行自体筋膜硬脑膜重建, D组加用外源性 bFGF, E组仅用明胶海绵,通过脑脊液漏研究、免疫组织化学方法研究外源性 bFGF对自体筋膜重建硬脑膜愈合过程的影响并用 RT- PCR方法研究内源性 bFGF mRNA的表达情况.[结果] 大鼠自体筋膜移植硬脑膜部位 bFGF表达明显; C、 D、 E组大鼠重建硬脑膜抵抗脑脊液漏压力值( mmH2O)分别为 311± 75, 497± 153, 338± 88,Ⅰ型胶原纤维表达值分别为 4.9± 0.8, 10.9± 1.6, 5.3± 0.9, D组均好于对照组( P< 0.05);内源性 bFGF mRNA的表达没有明显变化.[结论] 在自体筋膜移植硬脑膜的愈合过程中 bFGF可能起了重要的作用;外源性 bFGF处理的大鼠其移植筋膜愈合要好于对照组. 相似文献
88.
目的:观察转移因子口服液佐治小儿单纯性肾病综合征的疗效。方法:将75例诊断为单纯性肾病综合征的患儿随机分为治疗组和对照组,对照组主要采用泼尼松口服治疗,治疗组另加用转移因子口服液治疗。观察两组的感染率、复发率及治疗前后血IgG、IgA水平。结果:治疗组的感染率和复发率明显较低;治疗后血IgG、IgA水平明显提高,与对照组比较差异明显(P〈0.01)。结论:转移因子口服液佐治小儿单纯性肾病综合征可以降低患者的感染率和复发率,提高血IgG和IgA水平,是治疗肾病综合征的有效方法之一。 相似文献
89.
90.
Kun Hwang MD PhD Ei Tae Kim MD Se Il Lee MD DMSc 《The Journal of foot and ankle surgery》2005,44(6):473-477
The purpose of this study was to determine the genetic characteristics of foot polydactyly and identify its inheritance pattern by analyzing familial pedigree. Five cases from 2 Korean families were studied: 1 is a family whose members have been affected for 4 generations and the other for 2 generations. Using peripheral blood samples, we performed chromosomal analysis using the banding technique with Giemsa stain and karyotyping. We investigated the shape and structure of 46 chromosomes, looking for translation, deletion, inversion, ring chromosome, and isochromosome abnormalities. All peripheral blood samples demonstrated no chromosomal abnormalities, though the genetic nature of foot polydactyly and a new genetic locus was identified recently by other studies. Familial pedigree analysis suggested that polydactyly was inherited as an autosomal dominant trait in the first family. The mode of inheritance for the second family could not be determined due to an insufficient number of family members. The result of this study brought us to the conclusion that, while genetic factors play a major role in polydactyly, other factors may contribute to its occurrence. 相似文献