Analysis of Variance

方差分析
  • 文章类型: Journal Article
    提供定量结果的测量仪器的可靠性通常通过组内相关系数来评估。当参与者由单个评估者或设备重复测量时,或者,每个人都由一组不同的评分者评分,组内相关系数基于单因素方差分析模型。在计划可靠性研究时,必须确定参与者的数量和每个参与者的测量结果(即评估者的数量或重复测量的数量)。文献中确定了单向方差分析模型下三种不同的样本量确定方法,全部基于组内相关系数的置信区间。尽管可以识别八种不同的置信区间方法,尽管具有众所周知的较差的统计特性,但具有Fisher大样本方差近似的Wald置信区间仍然是最常用的。因此,这项工作的第一个目标是比较所有已确定的置信区间方法的统计特性,包括以前研究中忽略的那些方法.第二个目标是开发一种通用程序来使用所有方法确定样本量,因为封闭形式的公式并不总是可用的。此过程在RShiny应用程序中实现。最后,在计划可靠性研究时,我们为选择合适的样本量确定方法提供建议。
    Reliability of measurement instruments providing quantitative outcomes is usually assessed by an intraclass correlation coefficient. When participants are repeatedly measured by a single rater or device, or, are each rated by a different group of raters, the intraclass correlation coefficient is based on a one-way analysis of variance model. When planning a reliability study, it is essential to determine the number of participants and measurements per participant (i.e. number of raters or number of repeated measurements). Three different sample size determination approaches under the one-way analysis of variance model were identified in the literature, all based on a confidence interval for the intraclass correlation coefficient. Although eight different confidence interval methods can be identified, Wald confidence interval with Fisher\'s large sample variance approximation remains most commonly used despite its well-known poor statistical properties. Therefore, a first objective of this work is comparing the statistical properties of all identified confidence interval methods-including those overlooked in previous studies. A second objective is developing a general procedure to determine the sample size using all approaches since a closed-form formula is not always available. This procedure is implemented in an R Shiny app. Finally, we provide advice for choosing an appropriate sample size determination method when planning a reliability study.
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  • 文章类型: Meta-Analysis
    目的:系统评价创伤生活事件(TLE)与痴呆风险之间的关系。
    方法:系统评价和荟萃分析。
    方法:APA,心理信息,Embase和MEDLINE从成立到29.05.21,并在20.04.22更新。
    方法:发表在同行评审期刊上的原创研究文章,研究了年龄在60岁及以上的个体中TLE与所有痴呆之间的关联。两名研究人员使用纽卡斯尔-渥太华量表独立评估偏倚风险。我们进行了一般的逆方差随机效应荟萃分析,以提供TLE对痴呆风险影响的总体估计。
    方法:风险,与痴呆症风险相关的赔率和风险比。
    结果:最初,在搜索中检索了3,487项研究,其中7项研究被纳入荟萃分析,数据来自276,570名参与者。TLE与痴呆风险增加相关。创伤总体上具有1.21的合并HR(95%CI1.03,1.43,P=0.0001)。战争/大屠杀创伤和儿童创伤也与痴呆风险增加相关(HR=1.28(95%CI1.01-1.63,P=0.02)和HR=1.76(95%CI1.17-2.64,P=0.007))。
    结论:我们发现TLE与痴呆风险之间存在关联。未来的研究需要探索TLE的维度和个体水平因素,以更好地理解TLE与痴呆之间的关系。
    背景:PROSPEROCRD42021253090。
    To systematically review the association between traumatic life events (TLE) and dementia risk.
    Systematic review and meta-analysis.
    APA, PsychINFO, Embase and MEDLINE from their inception to 29.05.21 and updated on 20.04.22.
    Original research articles published in peer reviewed journals examining the association between TLE and all cause dementia in individuals aged 60 and over. Two researchers independently assessed the risk of bias using the Newcastle-Ottawa Scale. We conducted a generic inverse variance random effects meta-analysis to provide an overall estimate of TLE impact on dementia risk.
    Risk, odds and hazards ratios relating to dementia risk.
    Initially, 3,487 studies were retrieved in the search and seven studies were included in the meta-analysis with data being used from 276,570 participants. TLE were associated with increased dementia risk. Trauma in general had a pooled HR of 1.21, (95% CI 1.03, 1.43, P = 0.0001). War/ Holocaust trauma and childhood trauma were also associated with increased dementia risk (HR = 1.28 (95% CI 1.01-1.63, P = 0.02) and HR = 1.76 (95% CI 1.17-2.64, P = 0.007) respectively).
    We have found an association between TLE and dementia risk. Future research exploring the dimensions of TLE and individual level factors are needed to better understand the relationship between TLE and dementia.
    PROSPERO CRD42021253090.
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  • 文章类型: Journal Article
    目的:精浆细胞因子与生育和生殖健康有关,但是由于缺乏健康男性相关细胞因子浓度范围的参考数据,因此阻碍了其临床应用的发展。我们采用了一种系统的方法来收集有关正常精子症和/或可育男性的精浆(SP)中存在的免疫调节细胞因子浓度的最新证据,并评估了不同平台方法对细胞因子定量的影响。
    方法:使用PubMed进行了系统的文献检索,WebofScience,还有Scopus.数据库从开始到2022年6月30日进行搜索,包括在内,使用与精液和细胞因子相关的关键词的组合,仅限于人类参与者。从以英语编写的研究中提取了原始数据,其数值报告为明确定义为可育或正常精子症的男性精浆中特定细胞因子的浓度。
    结果:最初确定了总共3769种出版物,其中118人符合入选资格标准。在健康男性的精浆中检测到总共51种单独的细胞因子。报告每种细胞因子的研究数量范围为1至>20。报道的许多细胞因子的浓度与生育状态有关,包括IL6、CXCL8/IL8和TNFA,在已发表的研究之间差异很大。这与所使用的不同免疫测定方法有关,并且可能因缺乏确保精浆评估适用性的测定验证而加剧。由于研究之间的差异很大,从公布的数据中无法确定健康男性的准确参考范围。
    结论:在SP中检测到的细胞因子和趋化因子的浓度在研究和队列之间不一致且差异很大,限制电流容量以定义可育男性细胞因子浓度的参考范围。精浆加工和储存方法缺乏标准化,以及用于评估细胞因子丰度的平台的变化,是导致观察到的异质性的因素。为了提高精浆细胞因子分析的临床实用性,将需要标准化和方法学验证,以便可以定义健康可育男性的参考范围。本文受版权保护。保留所有权利。
    Seminal plasma cytokines are associated with fertility and reproductive health, but progressing their clinical utility is hampered by absence of reference data on concentration ranges of relevant cytokines in healthy men. We employed a systematic approach to assemble current evidence on the concentrations of immune regulatory cytokines present in seminal plasma (SP) of normozoospermic and/or fertile men and evaluated the impact of different platform methodologies for cytokine quantification.
    A systematic literature search was performed utilising PubMed, Web of Science and Scopus. Databases were searched from inception until 30th June 2022 inclusive, using combinations of keywords pertaining to seminal fluid and cytokines, and was restricted to human participants. Original data with values reported as concentration of specific cytokines in SP of men clearly defined as fertile or normozoospermic were extracted from studies written in English.
    A total of 3769 publications were initially identified, of which 118 fulfilled the eligibility criteria for inclusion. A total of 51 individual cytokines are detectable in SP of healthy men. The number of studies reporting on each cytokine range from 1 to >20. The reported concentrations for many cytokines linked with fertility status, including IL6, CXCL8/IL8, and TNFA, are highly variable between published studies. This is associated with the different immunoassay methodologies utilised and may be exacerbated by a lack of validation of assays to ensure suitability for SP assessment. Due to the large variation between studies, accurate reference ranges for healthy men cannot be determined from the published data.
    The concentrations of cytokines and chemokines detected in SP is inconsistent and highly variable between studies and cohorts, limiting current capacity to define reference ranges for cytokine concentrations in fertile men. The lack of standardisation in methods used to process and store SP, and variation in platforms used to evaluate cytokine abundance, are factors contributing to the observed heterogeneity. To progress the clinical utility of SP cytokine analysis will require standardisation and validation of methodologies so that reference ranges for healthy fertile men can be defined.
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  • 文章类型: Meta-Analysis
    世界卫生组织建议儿童每天平均进行60分钟的中等至剧烈的体育锻炼(MVPA),并应每周至少3天进行增强肌肉和骨骼的活动。公共卫生专业人员以及儿科研究人员已将学校确定为促进肌肉力量发展的战略场所。因此,本系统综述和荟萃分析的目的是调查以学校为基础的运动干预对改善儿童肌肉健康(MF)的疗效.在三个数据库中进行搜索。符合条件的标准是评估基于学校的运动干预对MF(即肌肉力量,肌肉力量,和局部肌肉耐力)在13岁以下的儿童中。美国国立卫生研究院工具评估了偏见的风险,使用随机效应逆方差分析计算合并效应大小(Hedges\'g)。17项研究招募了1653名儿童(28%的女孩进行了分析)。运动干预,主要是针对MF选定领域的联合干预措施,与局部肌肉耐力(g=0.6595%CI,0.13至1.17,p=0.020;I2=85.0%)以及肌肉力量和肌肉力量(g=0.3395%CI,0.16至0.51,p=0.001;I2=59.3%)的显着中度增加相关,使用每周≥3次的干预措施效果更高。我们的研究结果表明,以学校为基础的运动,包括力量锻炼练习可以改善儿童的MF,因此,为锻炼和体育活动的需求做好现代青年的准备。重点每周至少进行3天的校本肌肉和骨骼强化练习可能有助于支持女孩和男孩的肌肉健康发展。包括各种力量和调节活动的综合干预措施似乎是促进学校环境中肌肉健康的有希望的策略。未来的研究应标准化评估方法,以在学校环境中与儿童一起使用,并应包括对女孩的干预措施。越来越多的医疗保健提供者对此感兴趣,健身专业人员和体育教师鼓励参与精心设计的肌肉和骨骼强化练习。
    The World Health Organization recommends that children should engage in an average of 60 min of moderate-to-vigorous physical activity (MVPA) per day and should perform activities that strengthen muscle and bone at least 3 days a week. Public health professionals as well as pediatric researchers have identified schools as a strategic place to promote muscular strength development. Thus, the aim of this systematic review and meta-analysis was to investigate the efficacy of school-based exercise interventions for improving muscular fitness (MF) in children. Searches were conducted in three databases. Eligible criteria were randomized and non-randomized controlled trials evaluating the effects of school-based exercise interventions on MF (i.e. muscular strength, muscular power, and local muscular endurance) in children under 13 years of age. Risk of bias by the National Institutes of Health tool was appraised, and pooled effect sizes (Hedges\'g) were calculated using random-effects inverse-variance analyses. Seventeen studies enrolling 1653 children (28% girls were analyzed). Exercise interventions, mostly combined interventions targeting selected domains of MF, were associated with significant moderate increases in local muscular endurance (g = 0.65 95% CI, 0.13 to 1.17, p = 0.020; I2 = 85.0%) and muscular strength and muscular power (g = 0.33 95% CI, 0.16 to 0.51, p = 0.001; I2 = 59.3%), with higher effects using interventions with ≥3 sessions per week. Our findings indicate that school-based exercise that includes strength building exercises may improve MF in children and, consequently, prepare modern day youth for the demands of exercise and sport activities. HighlightsSchool-based muscle and bone strengthening exercises performed at least 3 days per week may serve to support the development of muscular fitness in girls and boysIntegrative interventions that include a variety of strength and conditioning activities seem to be a promising strategy to promote muscular fitness in school environmentFuture research should standardize assessment methods for use with children in the school context and should include interventions with girlsIt is of interest to a growing number of health care providers, fitness professionals and physical education teachers to encourage participation in well-designed muscle and bone strengthening exercises.
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  • 文章类型: Comparative Study
    基于能力的教育依赖于评估分数的有效性和可靠性。概化性(G)理论非常适合探索医学教育中评估工具的可靠性,但应用范围有限。本研究旨在使用G理论系统地回顾文献,以探讨医疗和外科技术技能的结构化评估的可靠性,并评估不同因素对方差的相对贡献。
    2020年6月,11个数据库,包括PubMed,从成立之初到2020年5月31日进行了搜索。合格的研究包括使用G理论在评估医学和外科技术技能的背景下探索可靠性。关于学习的描述性信息,评估背景,评估协议,被评估的参与者,并提取G分析。数据用于绘制G理论图并探索方差成分分析。进行了荟萃分析,以综合提取的有关方差和可靠性来源的数据。
    纳入了44项研究;其中,39人有足够的数据进行荟萃分析。总库包括35,284项独特评估,包括4,154名参与者的31,496项独特表演。人的方差具有44.2%的合并效应(95%置信区间[CI],36.8%-51.5%)。只有评估工具类型(客观结构化评估技术技能类型与基于任务的清单类型)对人的差异有显着影响。合并信度(G系数)为0.65(95%CI,.59-.70)。大多数研究包括决策研究(39,88.6%),并且通常似乎对评估者的表现比率更高,以实现足够可靠的评估。
    G理论越来越多地用于检查医学教育中技术技能评估的可靠性,但更严格的报告是有必要的。情境因素可能会影响方差分量,从而影响可靠性估计,应予以考虑,特别是在高风险的评估中。可靠性分析应该是开发技术技能评估的最佳实践。
    Competency-based education relies on the validity and reliability of assessment scores. Generalizability (G) theory is well suited to explore the reliability of assessment tools in medical education but has only been applied to a limited extent. This study aimed to systematically review the literature using G-theory to explore the reliability of structured assessment of medical and surgical technical skills and to assess the relative contributions of different factors to variance.
    In June 2020, 11 databases, including PubMed, were searched from inception through May 31, 2020. Eligible studies included the use of G-theory to explore reliability in the context of assessment of medical and surgical technical skills. Descriptive information on study, assessment context, assessment protocol, participants being assessed, and G-analyses was extracted. Data were used to map G-theory and explore variance components analyses. A meta-analysis was conducted to synthesize the extracted data on the sources of variance and reliability.
    Forty-four studies were included; of these, 39 had sufficient data for meta-analysis. The total pool included 35,284 unique assessments of 31,496 unique performances of 4,154 participants. Person variance had a pooled effect of 44.2% (95% confidence interval [CI], 36.8%-51.5%). Only assessment tool type (Objective Structured Assessment of Technical Skills-type vs task-based checklist-type) had a significant effect on person variance. The pooled reliability (G-coefficient) was 0.65 (95% CI, .59-.70). Most studies included decision studies (39, 88.6%) and generally seemed to have higher ratios of performances to assessors to achieve a sufficiently reliable assessment.
    G-theory is increasingly being used to examine reliability of technical skills assessment in medical education, but more rigor in reporting is warranted. Contextual factors can potentially affect variance components and thereby reliability estimates and should be considered, especially in high-stakes assessment. Reliability analysis should be a best practice when developing assessment of technical skills.
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  • 文章类型: Journal Article
    抗疟药,特别是基于青蒿素的联合疗法(ACTs),是减轻全球疟疾负担的重要工具,集中在撒哈拉以南非洲。以透明和标准化的方式进行和报告抗疟疗效研究,可以比较不同国家和时间段的疗效结果。本系统评价总结了与世卫组织实验室和报告指南有关的抗疟治疗效果研究的研究合规性,并评估了撒哈拉以南非洲的研究遵守这些指南的程度。我们纳入了在撒哈拉以南非洲进行的所有已发表的研究(2020年1月或之前),据报道,ACT对治疗无并发症的恶性疟原虫感染的疗效。主要结果是与WHO校正疗效统计分析指南一致的研究方法的复合指标。定义为一篇文章介绍了校正疗效的Kaplan-Meier生存分析或报告了分子和分母中排除新感染的符合方案分析.在581篇筛选的文章中,我们确定了279项进行审查.83%(232/279)的患者使用分子校正来区分新感染与复发性寄生虫血症的复发。只有45%(99/221)以治疗疗效为主要结果并进行分子校正的文章报告了以与WHO建议一致的方式计算的校正疗效结果。这些结果表明普遍不符合世卫组织推荐的分析方法,这可能会导致撒哈拉以南非洲地区在衡量和报告抗疟效果方面存在偏差。
    Antimalarials, in particular artemisinin-based combination therapies (ACTs), are critical tools in reducing the global burden of malaria, which is concentrated in sub-Saharan Africa. Performing and reporting antimalarial efficacy studies in a transparent and standardized fashion permit comparison of efficacy outcomes across countries and time periods. This systematic review summarizes study compliance with WHO laboratory and reporting guidance pertaining to antimalarial therapeutic efficacy studies and evaluates how well studies from sub-Saharan Africa adhered to these guidelines. We included all published studies (January 2020 or before) performed in sub-Saharan Africa where ACT efficacy for treatment of uncomplicated Plasmodium falciparum infection was reported. The primary outcome was a composite indicator for study methodology consistent with WHO guidelines for statistical analysis of corrected efficacy, defined as an article presenting a Kaplan-Meier survival analysis of corrected efficacy or reporting a per-protocol analysis where new infections were excluded from the numerator and denominator. Of 581 articles screened, we identified 279 for the review. Molecular correction was used in 83% (232/279) to distinguish new infections from recrudescences in subjects experiencing recurrent parasitemia. Only 45% (99/221) of articles with therapeutic efficacy as a primary outcome and performing molecular correction reported corrected efficacy outcomes calculated in a way consistent with WHO recommendations. These results indicate a widespread lack of compliance with WHO-recommended methods of analysis, which may result in biases in how antimalarial effectiveness is being measured and reported from sub-Saharan Africa.
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    文章类型: Journal Article
    OBJECTIVE: Characterization of sociodemographic and clinical aspects of patients admitted to the Orthopedic Department (OD) after observation in the Emergency Room (ER) with the diagnosis of septic arthritis (SA).
    METHODS: A retrospective, monocentric, cross-sectional study was conducted. Sociodemographic and clinical data on patients admitted to the OD with suspected SA between April 2014 and September 2019 were collected.
    RESULTS: One-hundred and ten patients were included. In the overall sample, most patients were male (n=61; 55.5%) with a median age of 70 (IQR=20) years old. Thirty-six patients (32.7%) had a previous history of hyperuricemia or gout, or had this diagnosis established at the time of their hospital admission. Monoarthritis was the most common form of presentation (n=106; 96.4%), with the knee being the most frequently involved joint (n=60; 54.5%). S. aureus was the most representative microorganism in synovial fluid (SF) cultures (n=33; 30.6%). SF cultures did not allow the identification of a causative microorganism in 53 cases submitted to arthrotomy (50.5%). Serum C-reactive protein (CRP) was a predictive factor for microorganism identification in SF cultures, with values ≥ 17.6 mg/dl presenting a sensibility and specificity of 60.8% and 77.4%, respectively [CI 95% (0.52 - 0.80)]. Patients with a diagnosis of hyperuricemia or gout presented a higher risk for a negative SF culture result (OR = 4.7 [CI 95% =1.9 - 11.5]).
    CONCLUSIONS: Elderly subjects with multiple comorbidities, namely cardiovascular risk factors, seem more prone to SA. Serum CRP appears to be a predictive factor for the identification of a causative microorganism. The higher risk of a negative SF culture in patients with hyperuricemia or gout should alert us for the possibility of misdiagnosis of SA in patients with an acute gout attack.
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  • 文章类型: Journal Article
    A high prevalence of cardiovascular risk factors including age, male sex, hypertension, diabetes, and tobacco use, has been reported in patients with Coronavirus disease 2019 (COVID-19) who experienced adverse outcome. The aim of this study was to investigate the relationship between cardiovascular risk factors and in-hospital mortality in patients with COVID-19.
    MEDLINE, Cochrane, Web of Sciences, and SCOPUS were searched for retrospective or prospective observational studies reporting data on cardiovascular risk factors and in-hospital mortality in patients with COVID-19. Univariable and multivariable age-adjusted analyses were conducted to evaluate the association between cardiovascular risk factors and the occurrence of in-hospital death.
    The analysis included 45 studies enrolling 18,300 patients. The pooled estimate of in-hospital mortality was 12% (95% CI 9-15%). The univariable meta-regression analysis showed a significant association between age (coefficient: 1.06; 95% CI 1.04-1.09; p < 0.001), diabetes (coefficient: 1.04; 95% CI 1.02-1.07; p < 0.001) and hypertension (coefficient: 1.01; 95% CI 1.01-1.03; p = 0.013) with in-hospital death. Male sex and smoking did not significantly affect mortality. At multivariable age-adjusted meta-regression analysis, diabetes was significantly associated with in-hospital mortality (coefficient: 1.02; 95% CI 1.01-1.05; p = 0.043); conversely, hypertension was no longer significant after adjustment for age (coefficient: 1.00; 95% CI 0.99-1.01; p = 0.820). A significant association between age and in-hospital mortality was confirmed in all multivariable models.
    This meta-analysis suggests that older age and diabetes are associated with higher risk of in-hospital mortality in patients infected by SARS-CoV-2. Conversely, male sex, hypertension, and smoking did not independently correlate with fatal outcome.
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  • 文章类型: Journal Article
    在分析实验化学数据时,通常有必要将研究设计的结构纳入化学计量/统计模型,以有效解决感兴趣的研究问题。方差分析-同时成分分析(ASCA)是在多变量数据的定量分析中包含此类信息的最突出的方法之一,特别是当变量数量很大时。本教程综述旨在以一种简单的方式解释ASCA是如何工作的,如何操作以及如何正确解释ASCA结果,平易近人的数学和视觉描述。给出了两个例子:第一个,模拟化学反应,用于说明ASCA步骤和第二个步骤,来自真实的化学生态学数据集,结果的解释。还提供了与ASCA密切相关的方法的概述,指出它们的差异和范围,以提供广泛的图片,以构建考虑实验设计的多变量模型。
    When analyzing experimental chemical data, it is often necessary to incorporate the structure of the study design into the chemometric/statistical models to effectively address the research questions of interest. ANOVA-Simultaneous Component Analysis (ASCA) is one of the most prominent methods to include such information in the quantitative analysis of multivariate data, especially when the number of variables is large. This tutorial review intends to explain in a simple way how ASCA works, how it is operated and how to correctly interpret ASCA results, with approachable mathematical and visual descriptions. Two examples are given: the first, a simulated chemical reaction, serves to illustrate the ASCA steps and the second, from a real chemical ecology data set, the interpretation of results. An overview of methods closely related to ASCA is also provided, pointing out their differences and scope, to give a wide-ranging picture of the available options to build multivariate models that take experimental design into account.
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  • 文章类型: Journal Article
    Joubert syndrome is a rare neurological manifestation usually present in late infancy or early childhood with characteristic episodes of abnormal breathing pattern along with the neurological and other systemic involvement.We report a case of confirmed Joubert syndrome present in the immediate neonatal period with isolated spells of oxygen desaturations not accompanied by the classically described breathing pattern and absent neurological symptoms causing delay in the diagnosis. Isolated oxygen desaturation episodes could be a presenting manifestation of Joubert syndrome in a neonatal period.
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