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Cox比例危险回归模型是医学随访研究、临床试验研究中分析生存资料最常用的多因素分析方法,但它不适合于处理分组生存资料或重叠严重的大样本生存数据。笔者对分组比例危险回归模型及其在大样本寿命表生存资料分析中的应用进行了讨论。最后结合实例借助于GLIM软件探讨它在肺癌随访资料预后因素分析中的应用。 相似文献
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比较多水平模型和潜变量增长曲线模型在纵向数据分析中的应用。文中以结直肠癌患者术后的生命质量情况为实例,比较两种方法的异同。结果表明两方法的参数估计值结果非常接近,多水平模型在模型构建时较为容易,而潜变量增长曲线模型在模型评价等方面具有优势。两方法均可很好地分析纵向观测的数据,且各有优点,研究者应根据需要选择合适的方法分析数据。 相似文献
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探讨纵向数据潜变量增长曲线模型及其在Mplus中的实现方法。通过实例采用Mplus软件处理某高校大学生心理健康状况纵向数据。结果表明潜变量增长曲线模型可以处理含有潜变量的纵向数据,能够比较总体发展趋势和个体发展的差异,纳入协变量可以提高模型拟合效果;采用Mplus软件实现潜变量增长曲线模型,程序简单,操作方便。纵向数据潜变量增长曲线模型及其在Mplus中的实现程序,可为实际应用尤其是流行病学队列研究提供统计方法学方面的指导和参考。 相似文献
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目的 利用机器学习算法与生存模型建立脂肪肝Joint联合预测模型,为有关单位进行脂肪肝健康管理提供理论依据。方法 选取2006—2016年某人群体检数据为研究对象,据模拟实验结果选择机器学习方法建立纵向亚模型,利用时依Cox模型建立生存亚模型,再联合建模。结果 XGBoost算法F-measure值最大,均方误差最小,建立纵向亚模型。XGBoost-Joint联合模型稳定性和拟合效果优于其他组合的Joint模型。结论 Joint联合模型将纵向亚模型与生存亚模型相联系,关联变量在模型中对脂肪肝患病风险的影响明显上升,说明纵向过程对生存结果的影响很大。 相似文献
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目的探讨广义估计方程和多水平模型的应用与临床纵向研究以解决个体重复观测数据内部的相关性问题。方法根据临床纵向实例数据的特点,拟合因变量为二分类的广义估计方程和多水平模型,并与一般logistic模型比较。结果广义估计方程和多水平模型的分析结果与一般logistic模型不同。由于未能考虑个体内重复观测数据的相关性,一般logistic模型错误显示临床分期与近期疗效相关,而广义估计方程和多水平模型分析结果则显示相关无统计学意义。经分层分析也未发现临床分期与近期疗效的关联。结论广义估计方程和多水平模型都能有效地考虑重复观测数据内部相关性并能处理有缺失值的资料。与多水平模型相比,广义估计方程的参数估计较为稳定,可有效的估计各解释变量的效应。 相似文献
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《Value in health》2020,23(11):1497-1508
ObjectivesLarge secondary databases, such as those containing insurance claims data, are increasingly being used to compare the effects and costs of treatments in routine clinical practice. Despite their appeal, however, caution must be exercised when using these data. In this study, we aimed to identify and assess the methodological quality of studies that used claims data to compare the effectiveness, costs, or cost-effectiveness of systemic therapies for breast cancer.MethodsWe searched Embase, the Cochrane Library, Medline, Web of Science, and Google Scholar for English-language publications and assessed the methodological quality using the Good Research for Comparative Effectiveness principles. This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under number CRD42018103992.ResultsWe identified 1251 articles, of which 106 met the inclusion criteria. Most studies were conducted in the United States (74%) and Taiwan (9%) and were based on claims data sets (35%) or claims data linked to cancer registries (58%). Furthermore, most included large samples (mean 17 130 patients) and elderly patients, and they covered various outcomes (eg, survival, adverse events, resource use, and costs). Key methodological shortcomings were the lack of information on relevant confounders, the risk of immortal time bias, and the lack of information on the validity of outcomes. Only a few studies performed sensitivity analyses.ConclusionsMany comparative studies of cost, effectiveness, and cost-effectiveness have been published in recent decades based on claims data, and the number of publications has increased over time. Despite the availability of guidelines to improve quality, methodological issues persist and are often inappropriately addressed or reported. 相似文献
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《Health policy (Amsterdam, Netherlands)》2015,119(4):549-557
This contribution presents systematic biases in the process of generating health data by using a step-by-step explanation of the DISEASE FILTER, a heuristic instrument that we designed in order to better understand and evaluate health data. The systematic bias in health data generally varies by data type (register versus survey data) and the operationalization of health outcomes. Self-reported subjective health and disease assessments, for instance, underlie a different selectivity than do data based on medical examinations or health care statistics. Although this is obvious, systematic approaches used to better understand the process of generating health data have been missing until now. We begin with the definitions and classifications of diseases that change (e.g. over time), describe the selective nature of access to and use of medical health care (e.g. depending on health insurance and gender), present biases in diagnoses (e.g. by gender and professional status), report these biases in relation to the decision for or against various treatment (e.g. by age and income), and finally outline the determinants of the treatments (ambulant versus stationary, e.g. via mobility and age). We then show how to apply the DISEASE FILTER to health data and discuss the benefits and shortcomings of our heuristic model. Finally, we give some suggestions on how to deal with biases in health data and how to avoid them. 相似文献
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Julia Eaton Ian Painter Don Olson William B Lober 《Online Journal of Public Health Informatics》2015,7(3)
Secondary use of clinical health data for near real-time public health
surveillance presents challenges surrounding its utility due to data quality
issues. Data used for real-time surveillance must be timely, accurate and
complete if it is to be useful; if incomplete data are used for surveillance,
understanding the structure of the incompleteness is necessary. Such data are
commonly aggregated due to privacy concerns. The Distribute project was a near
real-time influenza-like-illness (ILI) surveillance system that relied on
aggregated secondary clinical health data. The goal of this work is to
disseminate the data quality tools developed to gain insight into the data
quality problems associated with these data. These tools apply in general to any
system where aggregate data are accrued over time and were created through the
end-user-as-developer paradigm. Each tool was developed during the exploratory
analysis to gain insight into structural aspects of data quality. Our key
finding is that data quality of partially accruing data must be studied in the
context of accrual lag—the difference between the time an event occurs
and the time data for that event are received, i.e. the time at which data
become available to the surveillance system. Our visualization methods therefore
revolve around visualizing dimensions of data quality affected by accrual lag,
in particular the tradeoff between timeliness and completion, and the effects of
accrual lag on accuracy. Accounting for accrual lag in partially accruing data
is necessary to avoid misleading or biased conclusions about trends in indicator
values and data quality. 相似文献
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Suzanne Siminski Soyeon Kim Adel Ahmed Jake Currie Alex Benns Amy Ragsdale Marjan Javanbakht Pamina M. Gorbach the CPNO Cohort Investigators 《Online Journal of Public Health Informatics》2021,13(3)
Research data may have substantial impact beyond the original study objectives. The Collaborating Consortium of Cohorts Producing NIDA Opportunities (C3PNO) facilitates the combination of data and access to specimens from nine NIDA-funded cohorts in a virtual data repository (VDR).Unique challenges were addressed to create the VDR. An initial set of common data elements was agreed upon, selected based on their importance for a wide range of research proposals. Data were mapped to a common set of values. Bioethics consultations resulted in the development of various controls and procedures to protect against inadvertent disclosure of personally identifiable information. Standard operating procedures govern the evaluation of proposed concepts, and specimen and data use agreements ensure proper data handling and storage.Data from eight cohorts have been loaded into a relational database with tables capturing substance use, available specimens, and other participant data. A total of 6,177 participants were seen at a study visit within the past six months and are considered under active follow-up for C3PNO cohort participation as of the third data transfer, which occurred in January 2020. A total of 70,391 biospecimens of various types are available for these participants to test approved scientific hypotheses. Sociodemographic and clinical data accompany these samples.The VDR is a web-based interactive, searchable database available in the public domain, accessed at www.c3pno.org. The VDR are available to inform both consortium and external investigators interested in submitting concept sheets to address novel scientific questions to address high priority research on HIV/AIDS in the context of substance use. 相似文献
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本文分析了医院数据系统可能存在的安全风险,运用ORACLE数据库提供的数据备份和恢复工具,提出了一些针对性的数据备份和数据恢复的方法,建立一套简单实用的医院数据系统高速、有效的备份方案,使医院数据系统运行安全稳定。 相似文献
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