Underestimation of treatment effects in sequentially monitored clinical trials that did not stop early for benefit.

abstract：:Longitudinal zero-inflated count data are encountered frequently in substance-use research when assessing the effects of covariates and risk factors on outcomes. Often, both the time to a terminal event such as death or dropout and repeated measure count responses are collected for each subject. In this setting, the l...

journal_title：Statistical methods in medical research

authors： Zhu H,DeSantis SM,Luo S

更新日期：2018-04-01 00:00:00

abstract：:Cancer survival trend analyses are essential to describe accurately the way medical practices impact patients' survival according to the year of diagnosis. To this end, survival models should be able to account simultaneously for non-linear and non-proportional effects and for complex interactions between continuous v...

journal_title：Statistical methods in medical research

authors： Remontet L,Uhry Z,Bossard N,Iwaz J,Belot A,Danieli C,Charvat H,Roche L,CENSUR Working Survival Group.

更新日期：2019-08-01 00:00:00

abstract：:Data in many experiments arise as curves and therefore it is natural to use a curve as a basic unit in the analysis, which is termed functional data analysis (FDA). In longitudinal studies, recent developments in FDA have extended classical linear models and linear mixed effects models to functional linear models (als...

journal_title：Statistical methods in medical research

authors： Guo W

更新日期：2004-02-01 00:00:00

abstract：:Bayes or empirical Bayes methods to improve inferential accuracy for a population mean has been widely adopted in medical research. As the joint prior distribution of both the mean and variance parameters can be difficult to specify or estimate, most of these methods have relied on certain level of simplifications of ...

journal_title：Statistical methods in medical research

authors： Shen C

更新日期：2019-06-01 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：:It is now widely accepted that multiple imputation (MI) methods properly handle the uncertainty of missing data over single imputation methods. Several standard statistical software packages, such as SAS, R and STATA, have standard procedures or user-written programs to perform MI. The performance of these packages is...

journal_title：Statistical methods in medical research

authors： Yu LM,Burton A,Rivero-Arias O

更新日期：2007-06-01 00:00:00

abstract：:Multistate models provide an important method for analyzing a wide range of life history processes including disease progression and patient recovery following medical intervention. Panel data consisting of the states occupied by an individual at a series of discrete time points are often used to estimate transition i...

journal_title：Statistical methods in medical research

authors： Aralis H,Brookmeyer R

更新日期：2019-03-01 00:00:00

abstract：:Cohen's kappa coefficient, κ, is a statistical measure of inter-rater agreement or inter-annotator agreement for qualitative items. In this paper, we focus on interval estimation of κ in the case of two raters and binary items. So far, only asymptotic and bootstrap intervals are available for κ due to its complexity. ...

journal_title：Statistical methods in medical research

authors： Shan G,Wang W

更新日期：2017-04-01 00:00:00

abstract：:In many experiments and especially in translational and preclinical research, sample sizes are (very) small. In addition, data designs are often high dimensional, i.e. more dependent than independent replications of the trial are observed. The present paper discusses the applicability of max t-test-type statistics (mu...

journal_title：Statistical methods in medical research

authors： Konietschke F,Schwab K,Pauly M

更新日期：2020-11-24 00:00:00

abstract：:Statistical methods for carrying out asymptotic inferences (tests or confidence intervals) relative to one or two independent binomial proportions are very frequent. However, inferences about a linear combination of K independent proportions L = Σβ(i)p(i) (in which the first two are special cases) have had very little...

journal_title：Statistical methods in medical research

authors： Martín Andrés A,Alvarez Hernández M,Herranz Tejedor I

更新日期：2011-08-01 00:00:00

abstract：:We review the origins of backcalculation (or back projection) methods developed for the analysis of AIDS (acquired immunodeficiency syndrome) incidence data. These techniques have been used extensively for >15 years to deconvolute clinical case incidence, given knowledge of the incubation period distribution, to obtai...

journal_title：Statistical methods in medical research

authors： Donnelly CA,Ferguson NM,Ghani AC,Anderson RM

更新日期：2003-06-01 00:00:00

abstract：:Multilevel models were originally developed to allow linear regression or ANOVA models to be applied to observations that are not mutually independent. This lack of independence commonly arises due to clustering of the units of observations into 'higher level units' such as patients in hospitals. In linear mixed model...

journal_title：Statistical methods in medical research

authors： Rabe-Hesketh S,Yang S,Pickles A

更新日期：2001-12-01 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

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：: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：:When estimating a survival time distribution, the loss of information due to right censoring results in a loss of efficiency in the estimator. In many circumstances, however, repeated measurements on a longitudinal process which is associated with survival time are made throughout the observation time, and these measu...

journal_title：Statistical methods in medical research

authors： Hogan JW,Laird NM

更新日期：1998-03-01 00:00:00

abstract：:Most statistical developments in the joint modelling area have focused on the shared random-effect models that include characteristics of the longitudinal marker as predictors in the model for the time-to-event. A less well-known approach is the joint latent class model which consists in assuming that a latent class s...

journal_title：Statistical methods in medical research

authors： Proust-Lima C,Séne M,Taylor JM,Jacqmin-Gadda H

更新日期：2014-02-01 00:00:00

abstract：:This article outlines the statistical developments that have taken place in the use of the EM algorithm in emission and transmission tomography during the past decade or so. We discuss the statistical aspects of the modelling of the projection data for both the emission and transmission cases and define the relevant p...

journal_title：Statistical methods in medical research

authors： Kay J

更新日期：1997-03-01 00:00:00

abstract：:Estimating the long-term health impact of air pollution using an ecological spatio-temporal study design is a challenging task, due to the presence of residual spatio-temporal autocorrelation in the health counts after adjusting for the covariate effects. This autocorrelation is commonly modelled by a set of random ef...

journal_title：Statistical methods in medical research

authors： Lee D,Mitchell R

更新日期：2014-12-01 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 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：: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：:Non-parametric linkage analysis examines similarities among affected relatives in alleles of one or more genetic markers (pieces of DNA at known locations on a chromosome). The objective is to evaluate departures from the null hypothesis that the markers are not near a disease gene. Under the null hypothesis, Mendel's...

journal_title：Statistical methods in medical research

authors： Shih MC,Whittemore AS

更新日期：2001-02-01 00:00:00

abstract：:Surveys are key means of obtaining policy-relevant information not available from routine sources. Bias arising from non-participation is typically handled by applying weights derived from limited socio-demographic characteristics. This approach neither captures nor adjusts for differences in health and related behavi...

journal_title：Statistical methods in medical research

authors： Gray L,Gorman E,White IR,Katikireddi SV,McCartney G,Rutherford L,Leyland AH

更新日期：2020-04-01 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：: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：: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：: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

abstract：:DNA methylation has been shown to play an important role in many complex diseases. The rapid development of high-throughput DNA methylation scan technologies provides great opportunities for genomewide DNA methylation-disease association studies. As methylation is a dynamic process involving time, it is quite plausibl...

journal_title：Statistical methods in medical research

authors： Wang C,Shen Q,Du L,Xu J,Zhang H

更新日期：2018-09-01 00:00:00

abstract：:Cure rate models have been widely adopted for characterizing survival data that have long-term survivors. Under a mixture cure rate model where the population is a mixture of cured and susceptible subjects, a primary goal is to study covariate effects on the cure probability and survival function of the susceptible su...

journal_title：Statistical methods in medical research

authors： Fan X,Liu M,Fang K,Huang Y,Ma S

更新日期：2017-10-01 00:00:00