Bayesian analysis

贝叶斯分析
  • 文章类型: Journal Article
    背景:疗养院的居民容易出现认知能力下降,影响记忆力,视觉空间认知,和执行功能。认知能力下降会导致痴呆,需要优先干预。
    方法:本研究旨在调查使用数字游戏的干预措施是否能有效保护和改善养老院居民的认知功能。使用具有多个基线的单病例AB设计进行干预研究。该研究的参与者是五名65岁及以上的老年人,他们不经常玩数字游戏。这项研究持续了15周,包括基线(A阶段)和干预阶段(B阶段)。A阶段有五个基线(5至9周),随机分配参与者。在B阶段,参与者分别参与数字游戏(太空入侵者)。认知功能被评估为结果,使用大脑评估(通过互联网在平板电脑上执行)在16个测量点进行测量。五名参与者中有四名(两名女性和两名男性)被纳入分析。使用视觉检查和贝叶斯统计与多层次建模。
    结果:对图表的视觉检查显示,干预后大多数层的认知功能评分在数字记忆方面有所改善,单词的记忆,心理旋转测试(视觉空间能力),和大脑评估的总分。这些影响在多层次建模的分析中也很重要。
    结论:研究结果表明,使用数字游戏可以有效地保护和改善养老院居民的认知功能。
    背景:这项研究已在大学医院医学信息网络临床试验注册(UMIN000048677;公开名称:数字游戏干预对老年人认知功能的影响;注册日期:2022年8月30日)。
    BACKGROUND: Residents in nursing homes are prone to cognitive decline affecting memory, visuospatial cognition, and executive functions. Cognitive decline can lead to dementia, necessitating prioritized intervention.
    METHODS: The current study aimed to investigate whether an intervention using a digital game was effective for preserving and improving the cognitive function of residents in nursing homes. An intervention study was conducted using a single-case AB design with multiple baselines. The participants in the study were five older adults aged 65 and over who do not play digital games regularly. The study ran for 15 weeks, including a baseline (phase A) and an intervention phase (phase B). Phase A had five baselines (5 to 9 weeks) with random participant assignment. In phase B, participants engaged in a digital game (Space Invaders) individually. Cognitive function was assessed as the outcome, measured using the Brain Assessment (performed on a tablet through the Internet) at 16 measurement points. Four of five participants (two female and two male) were included in the analysis, using visual inspection and Bayesian statistics with multi-level modeling.
    RESULTS: Visual inspection of the graphs revealed cognitive function score improvements after the intervention for most layers in terms of memory of numbers, memory of words, mental rotation test (visuospatial ability), and total scores in the Brain Assessment. These effects were also significant in the analysis by multi-level modeling.
    CONCLUSIONS: The results suggest that the use of digital games may be effective for preserving and improving cognitive function among residents of nursing home.
    BACKGROUND: This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000048677; public title: Effect of a Digital Game Intervention for Cognitive Functions in Older People; registration date: August 30, 2022).
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  • 文章类型: Journal Article
    分析方法的发展,像许多其他学科一样,依赖于实验和数据分析。确定一篇论文或报告对纳入数据分析的研究的贡献通常留给审稿人的经验和良好的感觉,不依赖结构化准则。机器学习驱动分析的作用日益增强,其中结果基于计算机密集型算法应用。使用交叉验证来拟合其参数的预测模型的评估给回归模型的评估增加了挑战,估计可以很容易地复制。缺乏支持评论的结构增加了评论的不确定性和可变性。在本文中,考虑了统计评估的各个方面。我们为应用统计工作的审阅者提供清单,重点是分析方法的开发。核对表涵盖与统计分析检讨有关的六个方面,即:(1)研究设计,(2)频率分析中的算法和推理方法,(3)贝叶斯分析中的贝叶斯方法(如果相关),(4)选择性推理方面,(5)严格的测试性能和(6)介绍的结果。我们提供了这些元素的简要概述,为更精细的治疗提供参考。分析方法的稳健性分析用于说明如何针对清单中的问题实现改进。该论文针对的是工程师和经验丰富的研究人员。
    Analytic methods development, like many other disciplines, relies on experimentation and data analysis. Determining the contribution of a paper or report on a study incorporating data analysis is typically left to the reviewer\'s experience and good sense, without reliance on structured guidelines. This is amplified by the growing role of machine learning driven analysis, where results are based on computer intensive algorithm applications. The evaluation of a predictive model where cross validation was used to fit its parameters adds challenges to the evaluation of regression models, where the estimates can be easily reproduced. This lack of structure to support reviews increases uncertainty and variability in reviews. In this paper, aspects of statistical assessment are considered. We provide checklists for reviewers of applied statistics work with a focus on analytic method development. The checklist covers six aspects relevant to a review of statistical analysis, namely: (1) study design, (2) algorithmic and inferential methods in frequentism analysis, (3) Bayesian methods in Bayesian analysis (if relevant), (4) selective inference aspects, (5) severe testing properties and (6) presentation of findings. We provide a brief overview of these elements providing references for a more elaborate treatment. The robustness analysis of an analytical method is used to illustrate how an improvement can be achieved in response to questions in the checklist. The paper is aimed at both engineers and seasoned researchers.
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  • 文章类型: Journal Article
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  • 文章类型: Journal Article
    冠状病毒病在中国迅速蔓延,然后在全世界蔓延。科威特是受到这一流行病积极影响的国家之一。目的:本研究旨在为严重急性呼吸系统综合症冠状病毒2(SARS-CoV-2)感染患者的计数和这些计数随时间的变化率的分析提供一个适当的新框架。因此,我们考虑了SARS-CoV-2患者的数量,即,确诊病例,死亡,以及科威特的复苏,范围从2020年2月24日至2020年8月25日。方法:在这里,我们使用马尔可夫链蒙特卡罗(MCMC)模拟方法对SARS-CoV-2进行数据分析,以开发非均匀泊松过程(NHPP)的贝叶斯分析。为此,我们使用了NHPP的两个独特模型:线性强度函数和幂律过程。还讨论了判别方法,为确诊病例的每日基础数据选择更好的模型,死亡,SARS-CoV-2患者的康复情况。基于偏差信息标准(DIC)选择适当的模型。结果:DIC的值表明幂律过程在估计和呈现所有研究变量方面比线性强度函数表现更好。本研究探讨了所提出的研究框架对SARS-CoV-2新确诊病例分析的有用性和意义,回收,以及特定地区的死亡。结论:该研究结果将有助于卫生组织或当局根据当前的资源和大流行情况制定方法。所提供的框架可能有助于分析该地区COVID-19的第二层和第三层。分析每个研究变量的计数和每个变量的所有三层的比较分析是我们未来研究的目标。
    The coronavirus disease spread out rapidly in China and then in the whole world. Kuwait is one of those countries which are positively affected by this pandemic. Objective : The current study aims to provide an appropriate and novel framework for the analysis of the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infected patient\'s counts and rate of change in these counts with respect to time. Therefore, we considered the number of SARS- CoV-2 patients, i.e., confirmed cases, deaths, and recoveries for Kuwait, ranging from the 24th of February 2020 to the 25th of August 2020. Method : Here, we used the Markov Chain Monte Carlo (MCMC) simulation methods for the data analysis of SARS-CoV-2 to develop the Bayesian analysis of the Non-Homogeneous Poisson Process (NHPP). For this purpose, we used the two unique models of NHPP: the linear intensity function and the power law process. The discrimination methods are also discussed to select a better model for daily basis data of confirmed cases, deaths, and recoveries of SARS-CoV-2 patients. The appropriate model is selected based on the Deviance Information Criteria (DIC). Results : The value of DIC indicates that the power-law process performs better than the linear intensity functions for estimating and presenting all the study variables. The current study explored the usefulness and significance of the proposed research framework to analyze the SARS-CoV-2 new confirmed cases, recoveries, and deaths in a specific area. Conclusion : The findings of the study will be helpful for the health organizations or authorities to develop the approaches based on the current resources and situations due to the pandemic. The provided framework could be beneficial in analyzing the second and third layers of COVID-19 in the area. The analysis of the counts for each study variable and for each variable a comparative analysis of all the three layers is the aim of our future study.
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  • 文章类型: Case Reports
    Myoid gonadal stromal tumor represents a rare testicular neoplasm displaying smooth muscular and gonadal stromal differentiation. This entity has very few cases reported in the literature that describe heterogeneous clinical and pathological characteristics. Bayesian statistics provides a useful framework to combine information from diverse sources. We here presented a case series-the largest so far reported-of myoid gonadal stromal tumor (4 cases) with extensive morphologic, immunohistochemical, and molecular characterization, performed a systematic review of the literature (that identified 9 papers), and used a Bayesian data analysis to understand the characteristics of this disease. Our study collectively described 16 cases. This neoplasm is mainly found in adults (mean age about 40 years) and often has a size of about 3 cm. By morphology, the tumor can infiltrate testicular tubules and is composed of spindle cells; few mitoses can be seen (usually 2/10 HPF). Neoplastic cells are diffusely positive with α-smooth muscle actin with a tram-track staining pattern. S100 protein, FOXL2, and SF1 are also characteristically positive. Moreover, this neoplasm can display epithelial differentiation, in about half of the cases. In conclusion, we foresee the use of this statistical approach in pathology: our analysis allowed a more precise description of this rare entity.
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  • 文章类型: Journal Article
    Reconstructing reliable timescales for species evolution is an important and indispensable goal of modern biogeography. However, many factors influence the estimation of divergence times, and uncertainty in the inferred time trees remains a major issue that is often insufficiently acknowledged. We here focus on a fundamental problem of time tree analysis: the combination of slow-evolving (nuclear DNA) and fast-evolving (mitochondrial DNA) markers in a single time tree. Both markers differ in their suitability to infer divergences at different time scales (the \'genome-timescale-dilemma\'). However, strategies to infer shallow and deep divergences in a single time tree have rarely been compared empirically. Using Mediterranean amphibians as model system that is exceptional in its geographic and taxonomic completeness of available genetic information, we analyze 202 lineages of western Palearctic amphibians across the entire Mediterranean region. We compiled data of four nuclear and five mitochondrial genes and used twelve fossil calibration points widely acknowledged for amphibian evolution. We reconstruct time trees for an extensive lineage-level data set and compare the performances of the different trees: the first tree is based on primary fossil calibration and mitochondrial DNA, while the second tree is based on a combination of primary fossil and on secondary calibrations taken from a nuclear tree using mitochondrial DNA (two-step protocol). Focusing on a set of nodes that are most likely explained by vicariance, we statistically compare the reconstructed alternative time trees by applying a biogeographical plausibility test. Our two-step protocol outperformed the alternative approach in terms of spatial and temporal plausibility. It allows us to infer scenarios for Mediterranean amphibian evolution in eight geographic provinces. We identified several tectonic and climatic events explaining the majority of Mediterranean amphibian divergences, with Plio-Pleistocene climatic fluctuations being the dominant driver for intrageneric evolution. However, often more than one event could be invoked for a specific split. We give recommendations for the use of secondary calibrations in future molecular clock analyses at the community level.
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  • 文章类型: Journal Article
    背景:多标准决策分析(MCDA)代表了一种有前途的收益风险评估方法。我们的目标是开发实用的MCDA(EVIDEM[证据和价值:对决策的影响])的功能,以解决现实生活中的监管决策需求,纳入先进的药物流行病学,并使用案例研究测试所得的收益-风险框架。
    方法:将EVIDEM的干预结果域转化为包括临床疗效在内的一般获益-风险框架,患者报告的结果,和不良事件(AE)标准。相对获益-风险平衡(RBRB)的概念是为了在产品和治疗领域以及随着时间的推移具有可比性而开发的。证据矩阵旨在包括来自试验的最相关数据,观察性研究,和模型,包括贝叶斯和纵向建模。该框架与一组利益相关者一起进行了测试,使用efalizumab治疗银屑病作为回顾性病例研究。不确定性被探索。
    结果:MCDA获益-风险树适用于银屑病特异性亚标准。小组成员对福利分配了相似的权重(0.48;标准差,0.20-0.70)和风险(0.52;SD,0.10-0.60),有很大的变化反映了不同的观点。与安慰剂相比,小组成员得分反映出更高的疗效,与主动比较者相比,疗效较低,以及在许可后发现的严重和致命的AE。Efalizumab的RBRB在2004年的许可中为阳性(0.29,量表-1至+1),在2009年撤回其市场授权时,范围为-0.41(与主动比较者相比)至0.01(与安慰剂相比)。复检表明重现性好。小组成员承认良好的表面有效性以及在现实生活中评估中超出收益风险的标准的重要性。
    结论:该方法允许量化和可视化随着时间的推移和跨比较者的获益-风险。务实的MCDA旨在将收益风险和高级统计数据之外的标准整合在一起,从而支持MCDA的应用,以进一步对现实决策进行负责的收益风险评估。
    BACKGROUND: Multicriteria decision analysis (MCDA) represents a promising method for benefit-risk assessment. Our goal was to develop features of pragmatic MCDA (EVIDEM [Evidence and Value: Impact on DEcisionMaking]) addressing real-life regulatory decision-making needs, incorporate advanced pharmacoepidemiology, and test the resulting benefit-risk framework using a case study.
    METHODS: The Intervention Outcomes domain of EVIDEM was transformed into a generic benefit-risk framework including clinical efficacy, patient-reported outcomes, and adverse event (AE) criteria. The concept of relative benefit-risk balance (RBRB) was developed for comparability across products and therapeutic areas and over time. Evidence matrix was designed to include most relevant data from trials, observational studies, and models, including Bayesian and longitudinal modeling. The framework was tested with a panel of stakeholders using efalizumab for psoriasis as retrospective case study. Uncertainty was explored.
    RESULTS: The MCDA benefit-risk tree was adapted with psoriasis-specific subcriteria. Panelists assigned similar weights to benefits (0.48; SD, 0.20-0.70) and risks (0.52; SD, 0.10-0.60), with large variations reflecting diverse perspectives. Panelist scores reflected higher efficacy versus placebo, lower efficacy versus active comparators, and serious and fatal AEs identified postlicensing. Efalizumab\'s RBRB was positive at licensing in 2004 (0.29, scale -1 to +1) and ranged from -0.41 (vs active comparators) to 0.01 (vs placebo) in 2009, when its market authorization was withdrawn. Retesting indicated good reproducibility. Panelists acknowledged good face validity and the importance of criteria beyond benefit-risk in real-life assessments.
    CONCLUSIONS: The approach allows quantification and visualization of benefit-risk over time and across comparators. Combination of pragmatic MCDA designed to integrate criteria beyond benefit-risk and advanced statistics supports application of MCDA to further accountable benefit-risk assessments for real-life decision making.
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  • 文章类型: Journal Article
    撒丁岛特有CentaureafiliformisViv的所有已知种群。研究了(菊科),以了解地理和生态因素对该物种遗传结构的影响。对14个种群和234个人进行了采样。估计了28个地块的人口结构和生殖生态。群体遗传分析基于SSR标记。通过空间贝叶斯方法研究了遗传结构。检测到0.51个m-2个体的平均密度,成年人的患病率。鉴定出十种传粉者;实验证明了丝状C.自花授粉和无花果的能力。种群显示出He=0.576的平均杂合度值和高遗传分化(总体FST=0.218)。贝叶斯分析表明,五个是最可能的基因库来源。强调了种群之间地理距离和遗传距离之间的强相关性。丝状拟南芥的人口结构以成年人为主,这表明它是一种稳定回归或衰老的物种,投资于当地的持久性,而不是殖民能力。尽管分布分散,研究的种群没有遗传侵蚀的证据。遗传分化分析揭示了种群间非常高的分化水平,因此表明存在有效的基因流动障碍。一个普遍的结论是,种群分布导致所研究种群的遗传结构清晰,地理而不是生态正在塑造这个物种的当前分布。
    All known populations of the Sardinian endemic Centaurea filiformis Viv. (Asteraceae) were studied in order to understand the impact of both geographic and ecological factors on the genetic structuring of this species. Fourteen populations and 234 individuals were sampled. The demographic structure of the populations and the reproductive ecology were estimated in 28 plots. Population genetic analyses were based on SSR markers. Genetic structure was investigated by spatial Bayesian methods. Average densities of 0.51 individuals m-2 were detected, with a prevalence of adults. Ten species of pollinators were identified; C. filiformis ability to self-pollinate and myrmecochory were demonstrated experimentally. The populations displayed an average heterozygosity value of He  = 0.576 and high genetic differentiation (overall FST  = 0.218). Bayesian analysis suggests that five is the most probable number of gene pools of origin. A strong correlation between geographic distances and genetic distances among populations was highlighted. The demographic population structure of C. filiformis is dominated by adults, suggesting that it is a stable-regressive or senile species, investing more in local persistence than colonisation ability. Despite the scattered distribution, the populations studied do not present evidence of genetic erosion. The analysis of genetic differentiation reveals very high differentiation levels among populations, thus indicating that effective barriers exist against gene flow. A general conclusion is that population distribution results in a clear genetic structure for the populations studied, and that geography and not ecology is shaping the present distribution of this species.
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  • 文章类型: Journal Article
    计数结果几乎发生在所有学科中,比如医学,流行病学或生物学,但它们经常包含错误。最近,研究表明,慢性阻塞性肺疾病患者自我报告的加重次数可能被严重错计.受这个结果的激励,我们重新分析了慢性阻塞性肺疾病健康试验的数据,一项大型随机对照试验,以自我报告的慢性阻塞性肺疾病患者的加重次数作为结局。为了调整泊松和(零膨胀)负二项式模型响应中的错误计数误差,我们介绍小说,一般方法论。关键思想是制定一个零膨胀负二项模型来捕获错误机制。这种参数方法自动规避了先前建议的方法的缺点,该方法在错误分类框架中处理错误计算的结果。从外部研究的验证数据中得出响应误差模型参数的先验信息,并对其进行自适应加权以解决潜在的先验数据冲突。贝叶斯分层建模方法的结果表明,在原始研究中,治疗效果被高估了。然而,仔细检查发现,这一意外结果是治疗效果的时间依赖性的假象。
    Count outcomes occur in virtually all disciplines, such as medicine, epidemiology or biology, but they often contain error. Recently, it has been shown that self-reported numbers of exacerbations of Chronic Obstructive Pulmonary Disease patients can be considerably miscounted. Motivated by this result, we reanalysed data from the Towards a Revolution in Chronic Obstructive Pulmonary Disease Health trial, a large randomized controlled trial with the self-reported number of exacerbations of Chronic Obstructive Pulmonary Disease patients as outcome. To adjust for miscounting error in the response of Poisson and (zero-inflated) negative binomial models, we introduce novel, general methodology. The key idea is to formulate a zero-inflated negative binomial model to capture the error mechanism. This parametric approach automatically circumvents drawbacks of previously suggested methodology that treats miscounted outcomes in the misclassification framework. Prior information for the response error model parameters was elicited from validation data of an external study and adaptively weighted to account for potential prior-data conflict. The results of the Bayesian hierarchical modelling approach indicated that the treatment effect has been overestimated in the original study. However, closer inspection revealed that this unexpected result was an artefact of an unaccounted time dependency of the treatment effect.
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  • 文章类型: Journal Article
    当由于感兴趣的疾病的稀有性而导致临床试验的招募受到限制时,或由于道德原因,控制臂的招募受到限制时(例如,儿科研究或重要的未满足的医疗需求),利用历史控制来扩大预期收集的数据库可能是一个有吸引力的选择。将历史数据与随机数据相结合的统计方法,虽然考虑到两者之间的不相容性,最近被提出,并且仍然是一个活跃的研究领域。当前的文献缺乏方法之间的严格比较,但也缺乏有关其在实践中使用的指南。在本文中,我们对现有方法进行了比较,这些方法基于对新的抗菌疗法进行的验证性III期研究设计练习,该方法具有二元终点和单一历史数据集.提出了一种评估从历史控制数据中借用信息的不同方法的相对性能的程序,并讨论了与方法的选择和实施有关的实际问题。根据我们的检查,我们发现这些方法具有可比的性能,但我们建议使用强健的混合物,以便于实施。
    When recruitment into a clinical trial is limited due to rarity of the disease of interest, or when recruitment to the control arm is limited due to ethical reasons (eg, pediatric studies or important unmet medical need), exploiting historical controls to augment the prospectively collected database can be an attractive option. Statistical methods for combining historical data with randomized data, while accounting for the incompatibility between the two, have been recently proposed and remain an active field of research. The current literature is lacking a rigorous comparison between methods but also guidelines about their use in practice. In this paper, we compare the existing methods based on a confirmatory phase III study design exercise done for a new antibacterial therapy with a binary endpoint and a single historical dataset. A procedure to assess the relative performance of the different methods for borrowing information from historical control data is proposed, and practical questions related to the selection and implementation of methods are discussed. Based on our examination, we found that the methods have a comparable performance, but we recommend the robust mixture prior for its ease of implementation.
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