A corrected formulation for marginal inference derived from two-part mixed models for longitudinal semi-continuous data.

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：:Mixed models are widely used for the analysis of one repeatedly measured outcome. If more than one outcome is present, a mixed model can be used for each one. These separate models can be tied together into a multivariate mixed model by specifying a joint distribution for their random effects. This strategy has been u...

journal_title：Statistical methods in medical research

authors： Fieuws S,Verbeke G,Molenberghs G

更新日期：2007-10-01 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：: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 article re-examines parametric methods for the calculation of time specific reference intervals where there is measurement error present in the time covariate. Previous published work has commonly been based on the standard ordinary least squares approach, weighted where appropriate. In fact, this is an incorrect...

journal_title：Statistical methods in medical research

authors： Gillard J

更新日期：2015-12-01 00:00:00

abstract：:Within paediatric populations, there may be distinct age groups characterised by different exposure-response relationships. Several regulatory guidance documents have suggested general age groupings. However, it is not clear whether these categorisations will be suitable for all new medicines and in all disease areas....

journal_title：Statistical methods in medical research

authors： Wadsworth I,Hampson LV,Bornkamp B,Jaki T

更新日期：2020-09-01 00:00:00

abstract：:Many statistical studies report p-values for inferential purposes. In several scenarios, the stochastic aspect of p-values is neglected, which may contribute to drawing wrong conclusions in real data experiments. The stochastic nature of p-values makes their use to examine the performance of given testing procedures o...

journal_title：Statistical methods in medical research

authors： Vexler A,Yu J,Zhao Y,Hutson AD,Gurevich G

更新日期：2018-12-01 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：: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：: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：:Methods for the analysis of reliability of ordered categorical scales are discussed, focussing on the limitation of the single summary-weighted kappa coefficients. A symmetric matrix of kappa-type coefficients is suggested as an alternative. The method is proposed as being suitable for ordinal scale where there is no ...

journal_title：Statistical methods in medical research

authors： Roberts C,McNamee R

更新日期：2005-10-01 00:00:00

abstract：:In this paper age-space-time models based on one and two-dimensional P-splines with B-spline bases are proposed for smoothing mortality rates, where both fixed relative scale and scale invariant two-dimensional penalties are examined. Model fitting and inference are carried out using integrated nested Laplace approxim...

journal_title：Statistical methods in medical research

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

更新日期：2019-02-01 00:00:00

abstract：:Two tests are proposed for checking the linearity of nonparametric function in partially linear models. The first one is based on a Crámer-von Mises statistic. This test can detect the local alternative converging to the null at the parametric rate 1/square root n. A bootstrap resample technique is provided to calcula...

journal_title：Statistical methods in medical research

authors： Liang H

更新日期：2006-06-01 00:00:00

abstract：:Sample size calculations are needed to design and assess the feasibility of case-control studies. Although such calculations are readily available for simple case-control designs and univariate analyses, there is limited theory and software for multivariate unconditional logistic analysis of case-control data. Here we...

journal_title：Statistical methods in medical research

authors： Gail MH,Haneuse S

更新日期：2019-03-01 00:00:00

abstract：:Previous work has shown that individual randomized "proof-of-concept" (PoC) studies may be designed to maximize cost-effectiveness, subject to an overall PoC budget constraint. Maximizing cost-effectiveness has also been considered for arrays of simultaneously executed PoC studies. Defining Type III error as the oppor...

journal_title：Statistical methods in medical research

authors： He L,Du L,Antonijevic Z,Posch M,Korostyshevskiy VR,Beckman RA

更新日期：2020-09-21 00:00:00

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：: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：:A bivariate generalised linear mixed model is often used for meta-analysis of test accuracy studies. The model is complex and requires five parameters to be estimated. As there is no closed form for the likelihood function for the model, maximum likelihood estimates for the parameters have to be obtained numerically. ...

journal_title：Statistical methods in medical research

authors： Willis BH,Baragilly M,Coomar D

更新日期：2020-04-01 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：: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：:Monte Carlo evaluation of resampling-based tests is often conducted in statistical analysis. However, this procedure is generally computationally intensive. The pooling resampling-based method has been developed to reduce the computational burden but the validity of the method has not been studied before. In this arti...

journal_title：Statistical methods in medical research

authors： Fung WK,Yu K,Yang Y,Zhou JY

更新日期：2018-05-01 00:00:00

abstract：BACKGROUND:Recent literature on the comparison of machine learning methods has raised questions about the neutrality, unbiasedness and utility of many comparative studies. Reporting of results on favourable datasets and sampling error in the estimated performance measures based on single samples are thought to be the m...

journal_title：Statistical methods in medical research

authors： Khondoker M,Dobson R,Skirrow C,Simmons A,Stahl D

更新日期：2016-10-01 00:00:00

abstract：:In many applications of zero-inflated models, score tests are often used to evaluate whether the population heterogeneity as implied by these models is consistent with the data. The most frequently cited justification for using score tests is that they only require estimation under the null hypothesis. Because this es...

journal_title：Statistical methods in medical research

authors： Hsu WW,Todem D,Mawella NR,Kim K,Rosenkranz RR

更新日期：2020-12-01 00:00:00

abstract：:Accelerated failure time model is a popular model to analyze censored time-to-event data. Analysis of this model without assuming any parametric distribution for the model error is challenging, and the model complexity is enhanced in the presence of large number of covariates. We developed a nonparametric Bayesian met...

journal_title：Statistical methods in medical research

authors： Zhang Z,Sinha S,Maiti T,Shipp E

更新日期：2018-04-01 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：:We review recent work on the application of pseudo-observations in survival and event history analysis. This includes regression models for parameters like the survival function in a single point, the restricted mean survival time and transition or state occupation probabilities in multi-state models, e.g. the competi...

journal_title：Statistical methods in medical research

authors： Andersen PK,Perme MP

更新日期：2010-02-01 00:00:00

abstract：:This paper is concerned with stochastic models for the spread of an epidemic among a community of households, in which individuals mix uniformly within households and, in addition, uniformly at a much lower rate within the population at large. This two-level mixing structure has important implications for the threshol...

journal_title：Statistical methods in medical research

authors： Ball F,Lyne O

更新日期：2006-10-01 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：:Couples with diseases associated with the sexual chromosomes, as well as families in countries where the desire for a male is extreme, are interested in influencing the sex of the baby. We propose an original composite likelihood approach to analyse the relation between sex of the newborn and timing of the intercourse...

journal_title：Statistical methods in medical research

authors： Tiberi S,Scarpa B,Sartori N

更新日期：2018-11-01 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