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91.
92.
Selecting an appropriate working correlation structure is pertinent to clustered data analysis using generalized estimating equations (GEE) because an inappropriate choice will lead to inefficient parameter estimation. We investigate the well‐known criterion of QIC for selecting a working correlation structure, and have found that performance of the QIC is deteriorated by a term that is theoretically independent of the correlation structures but has to be estimated with an error. This leads us to propose a correlation information criterion (CIC) that substantially improves the QIC performance. Extensive simulation studies indicate that the CIC has remarkable improvement in selecting the correct correlation structures. We also illustrate our findings using a data set from the Madras Longitudinal Schizophrenia Study. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
93.
Bernard Farrell 《Journal of diabetes science and technology》2007,1(2):245-250
The continuous glucose monitor market is just starting to develop. Current trends in the availability of diabetes information tools highlight the need for standard data presentation for continuous glucose monitors. These trends and their implications are discussed. This article proposes a set of standards for blood glucose data presentation. If device manufacturers adopt these standards, they will ensure that their continuous glucose monitors meet both the short-term and the long-term needs of users. This should increase the demand for these monitors and enable future device developments that appeal to a wider range of users. 相似文献
94.
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
95.
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
96.
市场机制下政府调节与医疗管制制度框架的构建 总被引:4,自引:1,他引:3
医疗机构分类管理的政策确定了我国医疗服务的市场取向.我国医疗市场服务因其特殊的技术经济特点也存在一般意义上的市场失灵,使政府管制这一非市场治理机制的产生与存在成为必要,以弥补与矫正市场缺陷,保证医疗服务市场的规范运行和卫生改革的顺利推进. 相似文献
97.
敖琴英 《安徽卫生职业技术学院学报》2006,5(4):85-86
目的:探讨计算机辅助教学在医学遗传学教学中的作用.方法:将180名护理中专生按学年分为对照组和观察组,分别采用传统的教学方法和计算机辅助教学进行医学遗传学教学,并在学期末对两组学生进行理论与综合考试,并调查两组学生对各组教学方法的作用及满意度.结果:两组学生考试成绩比较,观察组明显好于对照组(P<0.05);两组学生对各自所在组教学方法的作用及满意度比较,观察组好于对照组(P<0.05),差异有显著性意义.结论:计算机辅助教学有利于增强学生的学习兴趣,提高学生的学习效果,是一种较好的医学遗传学教学方法. 相似文献
98.
护理本科生关爱能力调查分析 总被引:3,自引:0,他引:3
目的了解护理本科生关爱能力现状,为护理本科生关爱能力的培养提供依据。方法采用关爱能力评价表,对四川省4所医学院校579名护理本科生关爱能力进行问卷调查。结果护理本科生关爱能力评分为189.72±19.57,在各维度中耐心维度得分最高,勇气维度得分最低;不同性别、民族、是否独生子女关爱能力比较,差异无显著性意义(均P〉0.05);四年级护理本科生关爱能力评分显著高于二、三年级(均P〈0.05)。结论护理本科生关爱能力仍需提高,建议从实践关爱和课程设置等方面提高护理本科生的关爱能力。 相似文献
99.
Two thousand nine hundred and ninety-four reports of OSHA-reportable occupational injury or illness cases in 1984 from member companies of a national trade association of semiconductor manufacturing firms were analyzed. The 37 participating manufacturing facilities represented 16 companies employing over 95,000 persons, or approximately one-third of the U.S. work force for this industry in 1984. The annual incidence rate for all reportable injuries and illnesses was 2.7 per 100 full-time employees (FTE) for men and 3.7 per 100 FTE for women. Strains, sprains, or dislocations were the most frequently reported incidents (N = 956 [31.9%]), followed by cuts, lacerations, punctures, scratches, and abrasions (N = 445 [14.9%]), and chemical burns (N = 401 [13.4%]). Increased work-loss days per case were associated with manufacturing sites that did not have an employee health clinic on the premises, with custodial occupations, and with female gender. 相似文献
100.
Many epidemiological studies have shown the magnitude and seriousness of mental disorders in developing countries. However, mental health care remains unsatisfactory owing to lack of skilled manpower and many other social and medical priorities. General practitioners and other health personnel can significantly help in extending mental health care provided they receive adequate training during their medical curriculum. With this aim, the Department of Psychiatry at Addis Ababa University runs a 6-week full-time course for undergraduate medical students. Its chief objectives, teaching methods, achievements and shortcomings are discussed in the paper. 相似文献