A new approach to hierarchical data analysis: Targeted maximum likelihood estimation for the causal effect of a cluster-level exposure.

abstract：:Nonlinear mixed-effects modeling is a popular approach to describe the temporal trajectory of repeated measurements of clinical endpoints collected over time in clinical trials, to distinguish the within-subject and the between-subject variabilities, and to investigate clinically important risk factors (covariates) th...

journal_title：Statistical methods in medical research

authors： Yuan M,Xu XS,Yang Y,Xu J,Huang X,Tao F,Zhao L,Zhang L,Pinheiro J

更新日期：2019-12-01 00:00:00

abstract：:In reliability theory, diagnostic accuracy, and clinical trials, the quantity P ( X > Y ) + ...

journal_title：Statistical methods in medical research

authors： Verbeeck J,Deltuvaite-Thomas V,Berckmoes B,Burzykowski T,Aerts M,Thas O,Buyse M,Molenberghs G

更新日期：2020-12-01 00:00:00

abstract：:Early phase trials of complex interventions currently focus on assessing the feasibility of a large randomised control trial and on conducting pilot work. Assessing the efficacy of the proposed intervention is generally discouraged, due to concerns of underpowered hypothesis testing. In contrast, early assessment of e...

journal_title：Statistical methods in medical research

authors： Wilson DT,Walwyn RE,Brown J,Farrin AJ,Brown SR

更新日期：2016-06-01 00:00:00

abstract：:Guarding against false positive selections is important in many applications. We discuss methods based on subsampling and sample splitting for controlling the expected number of false positives and assigning p-values. They are generic and especially useful for high-dimensional settings. We review encouraging results f...

journal_title：Statistical methods in medical research

authors： Bühlmann P,Rütimann P,Kalisch M

更新日期：2013-10-01 00:00:00

abstract：:Propensity score methods are common for estimating a binary treatment effect when treatment assignment is not randomized. When exposure is measured on an ordinal scale (i.e. low-medium-high), however, propensity score inference requires extensions which have received limited attention. Estimands of possible interest w...

journal_title：Statistical methods in medical research

authors： Lopez MJ,Gutman R

更新日期：2017-04-01 00:00:00

abstract：:Binary logistic regression is one of the most frequently applied statistical approaches for developing clinical prediction models. Developers of such models often rely on an Events Per Variable criterion (EPV), notably EPV ≥10, to determine the minimal sample size required and the maximum number of candidate predictor...

journal_title：Statistical methods in medical research

authors： van Smeden M,Moons KG,de Groot JA,Collins GS,Altman DG,Eijkemans MJ,Reitsma JB

更新日期：2019-08-01 00:00:00

abstract：:A central assumption in the design and conduct of non-inferiority trials is that the active-control therapy will have the same degree of effectiveness in the planned non-inferiority trial as in the prior placebo-controlled trials used to define the non-inferiority margin. This is referred to as the 'constancy' assumpt...

journal_title：Statistical methods in medical research

authors： Hanscom B,Hughes JP,Williamson BD,Donnell D

更新日期：2019-10-01 00:00:00

abstract：:For semi-continuous data which are a mixture of true zeros and continuously distributed positive values, the use of two-part mixed models provides a convenient modelling framework. However, deriving population-averaged (marginal) effects from such models is not always straightforward. Su et al. presented a model that ...

journal_title：Statistical methods in medical research

authors： Tom BD,Su L,Farewell VT

更新日期：2016-10-01 00:00:00

abstract：:Studies of HIV dynamics in AIDS research are very important for understanding pathogenesis of HIV infection and for assessing the potency of antiviral therapies. Since the viral dynamic results from clinical data were first published by Ho et al. and Wei et al., the study of HIV-1 dynamics in vivo has drawn a great at...

journal_title：Statistical methods in medical research

authors： Wu H

更新日期：2005-04-01 00:00:00

abstract：:This paper presents a new model-based generalized functional clustering method for discrete longitudinal data, such as multivariate binomial and Poisson distributed data. For this purpose, we propose a multivariate functional principal component analysis (MFPCA)-based clustering procedure for a latent multivariate Gau...

journal_title：Statistical methods in medical research

authors： Lim Y,Cheung YK,Oh HS

更新日期：2020-11-01 00:00:00

abstract：:Excessive zeros are common in practice and may cause overdispersion and invalidate inference when fitting Poisson regression models. There is a large body of literature on zero-inflated Poisson models. However, methods for testing whether there are excessive zeros are less well developed. The Vuong test comparing a Po...

journal_title：Statistical methods in medical research

authors： He H,Zhang H,Ye P,Tang W

更新日期：2019-04-01 00:00:00

abstract：:Exposure measurement error in epidemiological studies is recognized as a feature that must be considered because of the potential bias that can result in estimates of the exposure-disease association. Most of the work to date has focused on methods of analysis that adjust for the resultant bias, but the implications o...

journal_title：Statistical methods in medical research

authors： Holford TR,Stack C

更新日期：1995-12-01 00:00:00

abstract：:Cluster randomized and multicentre trials evaluate the effect of a treatment on persons nested within clusters, for instance patients within clinics or pupils within schools. Although equal sample sizes per cluster are generally optimal for parameter estimation, they are rarely feasible. This paper addresses the relat...

journal_title：Statistical methods in medical research

authors： van Breukelen GJ,Candel MJ,Berger MP

更新日期：2008-08-01 00:00:00

abstract：:The ability to evaluate effects of factors on outcomes is increasingly important for studies that control some but not all of the factors. Although important advances have been made in methods of analysis for such partially controlled studies, work on designs has been limited. To help understand why, we review the mai...

journal_title：Statistical methods in medical research

authors： Li F,Frangakis CE

更新日期：2005-08-01 00:00:00

abstract：:Agreement between two methods of clinical measurement can be quantified using the differences between observations made using the two methods on the same subjects. The 95% limits of agreement, estimated by mean difference +/- 1.96 standard deviation of the differences, provide an interval within which 95% of differenc...

journal_title：Statistical methods in medical research

authors： Bland JM,Altman DG

更新日期：1999-06-01 00:00:00

abstract：:We consider two exact unconditional procedures to test the difference between two multinomials with ordered categorical data. Exact unconditional procedures are compared to other approaches based on the Wilcoxon mid-rank test and the proportional odds model. We use a real example from an arthritis pain study to illust...

journal_title：Statistical methods in medical research

authors： Shan G,Ma C

更新日期：2016-02-01 00:00:00

abstract：:The positivity assumption, or the experimental treatment assignment (ETA) assumption, is important for identifiability in causal inference. Even if the positivity assumption holds, practical violations of this assumption may jeopardize the finite sample performance of the causal estimator. One of the consequences of p...

journal_title：Statistical methods in medical research

authors： Ju C,Schwab J,van der Laan MJ

更新日期：2019-06-01 00:00:00

abstract：:Pediatric cardiac surgery may lead to poor outcomes such as acute kidney injury (AKI) and prolonged hospital length of stay (LOS). Plasma and urine biomarkers may help with early identification and prediction of these adverse clinical outcomes. In a recent multi-center study, 311 children undergoing cardiac surgery we...

journal_title：Statistical methods in medical research

authors： Wang Z,Ma S,Zappitelli M,Parikh C,Wang CY,Devarajan P

更新日期：2016-12-01 00:00:00

abstract：:The random effects model in meta-analysis is a standard statistical tool often used to analyze the effect sizes of the quantity of interest if there is heterogeneity between studies. In the special case considered here, meta-analytic data contain only the sample means in two treatment arms and the sample sizes, but no...

journal_title：Statistical methods in medical research

authors： Sangnawakij P,Böhning D,Niwitpong SA,Adams S,Stanton M,Holling H

更新日期：2019-01-01 00:00:00

abstract：:In this paper, we develop a simple diagnostic test for the random-effects distribution in mixed models. The test is based on the gradient function, a graphical tool proposed by Verbeke and Molenberghs to check the impact of assumptions about the random-effects distribution in mixed models on inferences. Inference is c...

journal_title：Statistical methods in medical research

authors： Efendi A,Drikvandi R,Verbeke G,Molenberghs G

更新日期：2017-04-01 00:00:00

abstract：:Colorectal cancer is the second leading cause of death from cancer in the United States. To facilitate the efficiency of colorectal cancer screening, there is a need to stratify risk for colorectal cancer among the 90% of US residents who are considered "average risk." In this article, we investigate such risk stratif...

journal_title：Statistical methods in medical research

authors： Lin Y,Yu M,Wang S,Chappell R,Imperiale TF

更新日期：2016-08-01 00:00:00

abstract：:Measurement error is a serious problem in the analysis of epidemiological data. In the past 20 years, a large number of methods for the correction of measurement error have been developed. While at the beginning mostly methods for cohort studies were considered, recently more attention has been paid to case-control st...

journal_title：Statistical methods in medical research

authors： Thürigen D,Spiegelman D,Blettner M,Heuer C,Brenner H

更新日期：2000-10-01 00:00:00

abstract：:Repeated measures and multivariate outcomes are an increasingly common feature of trials. Their joint analysis by means of random effects and latent variable models is appealing but patterns of heterogeneity in outcome profile may not conform to standard multivariate normal assumptions. In addition, there is much inte...

journal_title：Statistical methods in medical research

authors： Pickles A,Croudace T

更新日期：2010-06-01 00:00:00

abstract：:Competing risks data often exist within a center in multi-center randomized clinical trials where the treatment effects or baseline risks may vary among centers. In this paper, we propose a subdistribution hazard regression model with multivariate frailty to investigate heterogeneity in treatment effects among centers...

journal_title：Statistical methods in medical research

authors： Ha ID,Christian NJ,Jeong JH,Park J,Lee Y

更新日期：2016-12-01 00:00:00

abstract：:In this paper we review methods of cluster analysis in the context of classifying patients on the basis of clinical and/or laboratory type observations. Both hierarchical and non-hierarchical methods of clustering are considered, although the emphasis is on the latter type, with particular attention devoted to the mix...

journal_title：Statistical methods in medical research

authors： McLachlan GJ

更新日期：1992-01-01 00:00:00

abstract：:It is a common practice to analyze longitudinal data frequently arisen in medical studies using various mixed-effects models in the literature. However, the following issues may standout in longitudinal data analysis: (i) In clinical practice, the profile of each subject's response from a longitudinal study may follow...

journal_title：Statistical methods in medical research

authors： Huang Y,Chen J,Yin P

更新日期：2017-02-01 00:00:00

abstract：:The analysis of fecundity data is challenging and requires consideration of both highly timed and interrelated biologic processes in the context of essential behaviors such as sexual intercourse during the fertile window. Understanding human fecundity is further complicated by presence of a sterile population, i.e. co...

journal_title：Statistical methods in medical research

authors： McLain AC,Sundaram R,Buck Louis GM

更新日期：2016-02-01 00:00:00

abstract：:In medical experiments with the objective of testing the equality of two means, data are often partially paired by design or because of missing data. The partially paired data represent a combination of paired and unpaired observations. In this article, we review and compare nine methods for analyzing partially paired...

journal_title：Statistical methods in medical research

authors： Guo B,Yuan Y

更新日期：2017-06-01 00:00:00

abstract：:We propose a hierarchical Bayesian methodology to model spatially or spatio-temporal clustered survival data with possibility of cure. A flexible continuous transformation class of survival curves indexed by a single parameter is used. This transformation model is a larger class of models containing two special cases ...

journal_title：Statistical methods in medical research

authors： Hurtado Rúa SM,Dey DK

更新日期：2016-02-01 00:00:00

abstract：:Tree-based methods are very powerful and popular tools for analysing survival data with right-censoring. The existing methods assume that the true time-to-event and the censoring times are independent given the covariates. We propose different ways to build survival forests when dependent censoring is suspected, by us...

journal_title：Statistical methods in medical research

authors： Moradian H,Larocque D,Bellavance F

更新日期：2019-02-01 00:00:00