Statistical methods for HIV dynamic studies in AIDS clinical trials.

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：:Medical research commonly relies on the combination of 2 x 2 tables of counted data for making inferences about treatment effects or about the causes of disease. This article reviews point estimation and interval estimation for a common odds ratio. Traditional methods for providing these estimates face special challen...

journal_title：Statistical methods in medical research

authors： Emerson JD

更新日期：1994-01-01 00:00:00

abstract：:We propose a novel likelihood method for analyzing time-to-event data when multiple events and multiple missing data intervals are possible prior to the first observed event for a given subject. This research is motivated by data obtained from a heart monitor used to track the recovery process of subjects experiencing...

journal_title：Statistical methods in medical research

authors： Green CL,Brownie C,Boos DD,Lu JC,Krucoff MW

更新日期：2016-04-01 00:00:00

abstract：:Conditional two-part random-effects models have been proposed for the analysis of healthcare cost panel data that contain both zero costs from the non-users of healthcare facilities and positive costs from the users. These models have been extended to accommodate more flexible data structures when using the generalize...

journal_title：Statistical methods in medical research

authors： Zhang B,Liu W,Hu Y

更新日期：2018-10-01 00:00:00

abstract：:I comment here on a recent paper in this journal, on the fitting of truncated normal distributions by the EM algorithm. I show that the fitting of such distributions by direct numerical maximization of likelihood (rather than EM) is straightforward, contrary to an assertion made by the authors of that paper. ...

journal_title：Statistical methods in medical research

authors： MacDonald IL

更新日期：2018-12-01 00:00:00

abstract：:The probability model for periodic screening was extended to provide statistical inference for sensitivity depending on sojourn time, in which the sensitivity was modeled as a function of time spent in the preclinical state and the sojourn time. The likelihood function with the proposed sensitivity model was then eval...

journal_title：Statistical methods in medical research

authors： Kim S,Wu D

更新日期：2016-04-01 00:00:00

abstract：:Immunotherapy, gene therapy or adoptive cell therapies, such as the chimeric antigen receptor+ T-cell therapies, have demonstrated promising therapeutic effects in oncology patients. We consider statistical designs for dose-finding adoptive cell therapy trials, in which the monotonic dose-response relationship assumed...

journal_title：Statistical methods in medical research

authors： Lin X,Ji Y

更新日期：2020-12-16 00:00:00

abstract：:Spatial resolution plays an important role in functional magnetic resonance imaging studies as the signal-to-noise ratio increases linearly with voxel volume. In scientific studies, where functional magnetic resonance imaging is widely used, the standard spatial resolution typically used is relatively low which ensure...

journal_title：Statistical methods in medical research

authors： Liu Z,Bartsch AJ,Berrocal VJ,Johnson TD

更新日期：2019-04-01 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：:In multi-regional trials, the underlying overall and region-specific accrual rates often do not hold constant over time and different regions could have different start-up times, which combined with initial jump in accrual within each region often leads to a discontinuous overall accrual rate, and these issues associa...

journal_title：Statistical methods in medical research

authors： Deng Y,Zhang X,Long Q

更新日期：2017-04-01 00:00:00

abstract：:This study proposes semiparametric models for analysis of hierarchical count data containing excess zeros and overdispersion simultaneously. The methods discussed in this paper handle nonlinear covariate effects through flexible semiparametric multilevel regression techniques. This is performed by providing a comprehe...

journal_title：Statistical methods in medical research

authors： Mahmoodi M,Moghimbeigi A,Mohammad K,Faradmal J

更新日期：2018-04-01 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：: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：:To project national hepatitis C virus (HCV) burden, unbiased estimation of HCV progression to liver cirrhosis is required for the whole community of HCV-infected individuals. However, widely varying estimates of progression rates to cirrhosis have been produced. This disparity is partly associated with the statistical...

journal_title：Statistical methods in medical research

authors： Fu B,Tom BD,Bird SM

更新日期：2009-06-01 00:00:00

abstract：:Cancer mortality risk estimates are essential for planning resource allocation and designing and evaluating cancer prevention and management strategies. However, mortality figures generally become available after a few years, making necessary to develop reliable procedures to provide current and near future mortality ...

journal_title：Statistical methods in medical research

authors： Ugarte MD,Goicoa T,Etxeberria J,Militino AF

更新日期：2012-10-01 00:00:00

abstract：:The change-point model has drawn much attention over the past few decades. It can accommodate the jump process, which allows for changes of the effects before and after the change point. Intellectual disability is a long-term disability that impacts performance in cognitive aspects of life and usually has its onset pr...

journal_title：Statistical methods in medical research

authors： Cai B,Lawson AB,McDermott S,Aelion CM

更新日期：2016-04-01 00:00:00

abstract：:Dependent binary response data arise frequently in practice due to repeated measurements in longitudinal studies or to subsampling primary sampling units as in fields such as teratology and ophthalmology. Several classes of approaches have recently been proposed to analyse such repeated binary outcome data. The differ...

journal_title：Statistical methods in medical research

authors： Neuhaus JM

更新日期：1992-01-01 00:00:00

abstract：:Ordinal classification scales are commonly used to define a patient's disease status in screening and diagnostic tests such as mammography. Challenges arise in agreement studies when evaluating the association between many raters' classifications of patients' disease or health status when an ordered categorical scale ...

journal_title：Statistical methods in medical research

authors： Nelson KP,Edwards D

更新日期：2018-03-01 00:00:00

abstract：:Cluster analysis via a finite mixture model approach is considered. With this approach to clustering, the data can be partitioned into a specified number of clusters g by first fitting a mixture model with g components. An outright clustering of the data is then obtained by assigning an observation to the component to...

journal_title：Statistical methods in medical research

authors： McLachlan GJ,Chang SU

更新日期：2004-10-01 00:00:00

abstract：:This work presents a brief overview of Markov models in cancer screening evaluation and focuses on two specific models. A three-state model was first proposed to estimate jointly the sensitivity of the screening procedure and the average duration in the preclinical phase, i.e. the period when the cancer is asymptomati...

journal_title：Statistical methods in medical research

authors： Uhry Z,Hédelin G,Colonna M,Asselain B,Arveux P,Rogel A,Exbrayat C,Guldenfels C,Courtial I,Soler-Michel P,Molinié F,Eilstein D,Duffy SW

更新日期：2010-10-01 00:00:00

abstract：:In this paper, we describe a Bayesian hierarchical Poisson model for the prospective analysis of data for infectious diseases. The proposed model consists of two components. The first component describes the behavior of disease during nonepidemic periods and the second component represents the increase in disease coun...

journal_title：Statistical methods in medical research

authors： Corberán-Vallet A,Lawson AB

更新日期：2014-12-01 00:00:00

abstract：:Many non-experimental studies use propensity-score methods to estimate causal effects by balancing treatment and control groups on a set of observed baseline covariates. Full matching on the propensity score has emerged as a particularly effective and flexible method for utilizing all available data, and creating well...

journal_title：Statistical methods in medical research

authors： Austin PC,Stuart EA

更新日期：2017-12-01 00:00:00

abstract：:This paper reviews the application of statistical models to outbreaks of two common respiratory viral diseases, measles and influenza. For each disease, we look first at its epidemiological characteristics and assess the extent to which these either aid or hinder modelling. We then turn to the models that have been de...

journal_title：Statistical methods in medical research

authors： Cliff AD,Haggett P

更新日期：1993-01-01 00:00:00

abstract：:Estimation of the effect of a binary exposure on an outcome in the presence of confounding is often carried out via outcome regression modelling. An alternative approach is to use propensity score methodology. The propensity score is the conditional probability of receiving the exposure given the observed covariates a...

journal_title：Statistical methods in medical research

authors： Williamson E,Morley R,Lucas A,Carpenter J

更新日期：2012-06-01 00:00:00

abstract：:The classical and most commonly used approach to building prediction intervals is the parametric approach. However, its main drawback is that its validity and performance highly depend on the assumed functional link between the covariates and the response. This research investigates new methods that improve the perfor...

journal_title：Statistical methods in medical research

authors： Roy MH,Larocque D

更新日期：2020-01-01 00:00:00

abstract：:This paper presents and compares several methods of measuring continuous baseline covariate imbalance in clinical trial data. Simulations illustrate that though the t-test is an inappropriate method of assessing continuous baseline covariate imbalance, the test statistic itself is a robust measure in capturing imbalan...

journal_title：Statistical methods in medical research

authors： Ciolino JD,Martin RH,Zhao W,Hill MD,Jauch EC,Palesch YY

更新日期：2015-04-01 00:00:00

abstract：:This paper reviews models for incomplete continuous and categorical longitudinal data. In terms of Rubin's classification of missing value processes we are specifically concerned with the problem of nonrandom missingness. A distinction is drawn between the classes of selection and pattern-mixture models and, using sev...

journal_title：Statistical methods in medical research

authors： Kenward MG,Molenberghs G

更新日期：1999-03-01 00:00:00

abstract：:Mixed models estimated by maximum likelihood and marginal models estimated by generalized estimating equations are the standard methods for the analysis of longitudinal data. However, their use is highly debated when attrition may be due to death. While some authors consider that mixed model estimates are interpretabl...

journal_title：Statistical methods in medical research

authors： Rouanet A,Helmer C,Dartigues JF,Jacqmin-Gadda H

更新日期：2019-02-01 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：:In many health studies, researchers are interested in estimating the treatment effects on the outcome around and through an intermediate variable. Such causal mediation analyses aim to understand the mechanisms that explain the treatment effect. Although multiple mediators are often involved in real studies, most of t...

journal_title：Statistical methods in medical research

authors： Taguri M,Featherstone J,Cheng J

更新日期：2018-01-01 00:00:00