Analysis of clustered competing risks data using subdistribution hazard models with multivariate frailties.

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：: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：:This article is motivated by jointly modelling longitudinal and time-to-event clinical data of patients with diabetes and end-stage renal disease. All patients are on the waiting list for the pancreas transplant after kidney transplant, and some of them have a pancreas transplant before kidney transplant failure or de...

journal_title：Statistical methods in medical research

authors： Dong JJ,Wang S,Wang L,Gill J,Cao J

更新日期：2019-09-01 00:00:00

abstract：:Recently, the joint analysis of longitudinal and survival data has been an active research area. Most joint models focus on survival data with only one type of failure. The research on joint modeling of longitudinal and competing risks survival data is sparse. Even so, many joint models for this type of data assume pa...

journal_title：Statistical methods in medical research

authors： Lu T

更新日期：2017-10-01 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：: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：:There is debate whether clinical trials with suboptimal power are justified and whether results from large studies are more reliable than the (combined) results of smaller trials. We quantified the error rates for evaluations based on single conventionally powered trials (80% or 90% power) versus evaluations based on ...

journal_title：Statistical methods in medical research

authors： IntHout J,Ioannidis JP,Borm GF

更新日期：2016-04-01 00:00:00

abstract：:The analysis of walking behavior in a physical activity intervention is considered. A Bayesian latent structure modeling approach is proposed whereby the ability and willingness of participants is modeled via latent effects. The dropout process is jointly modeled via a linked survival model. Computational issues are a...

journal_title：Statistical methods in medical research

authors： Lawson AB,Ellerbe C,Carroll R,Alia K,Coulon S,Wilson DK,VanHorn ML,George SM

更新日期：2016-12-01 00:00:00

abstract：:In the clinical development of some new infectious disease drugs, early clinical pharmacology trials may predict with high confidence that the efficacious doses are well below the range of the safety margin. In this case, a dose-ranging study may be unnecessary after a proof-of-concept (PoC) study testing the highest ...

journal_title：Statistical methods in medical research

authors： Fan XF,Gallo P,Su G,Menton R,Segal F

更新日期：2019-12-01 00:00:00

abstract：:Clinical trials investigating the efficacy of two or more doses of an experimental treatment compared to a single reference arm are not uncommon. In such situations, if each dose is compared to the reference arm using an un-adjusted significance level, consideration of the Type I familywise error is likely to be requi...

journal_title：Statistical methods in medical research

authors： Fernandes N,Stone A

更新日期：2011-12-01 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：: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：: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：:Statistical models of breast cancer tumour progression have been used to further our knowledge of the natural history of breast cancer, to evaluate mammography screening in terms of mortality, to estimate overdiagnosis, and to estimate the impact of lead-time bias when comparing survival times between screen detected ...

journal_title：Statistical methods in medical research

authors： Isheden G,Humphreys K

更新日期：2019-03-01 00:00:00

abstract：:Sample selection arises when the outcome of interest is partially observed in a study. Although sophisticated statistical methods in the parametric and non-parametric framework have been proposed to solve this problem, it is yet unclear how to deal with selectively missing covariate data using simple multiple imputati...

journal_title：Statistical methods in medical research

authors： Ogundimu EO,Collins GS

更新日期：2019-01-01 00:00:00

abstract：:A dynamic treatment regime is a set of decision rules for how to treat a patient at multiple time points. At each time point, a treatment decision is made depending on the patient's medical history up to that point. We consider the infinite-horizon setting in which the number of decision points is very large. Specific...

journal_title：Statistical methods in medical research

authors： Goldberg Y,Pollak M,Mitelpunkt A,Orlovsky M,Weiss-Meilik A,Gorfine M

更新日期：2017-08-01 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：:In this paper, a new allocation rule for treatment assignments in sequential clinical trials is proposed. The stratified and randomized play-the-winner rule (SRPWR) is an extension of the randomized play-the-winner rule to more than two treatments. It is applicable to cases where the probabilities of success of a trea...

journal_title：Statistical methods in medical research

authors： Liang Y,Carriere KC

更新日期：2008-12-01 00:00:00

abstract：:Evaluation of medical imaging devices often involves clinical studies where multiple readers (MR) read images of multiple cases (MC) for a clinical task, which are often called MRMC studies. In addition to sizing patient cases as is required in most clinical trials, MRMC studies also require sizing readers, since both...

journal_title：Statistical methods in medical research

authors： Huang Z,Samuelson F,Tcheuko L,Chen W

更新日期：2020-06-01 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：:The maximal procedure is a restricted randomization method that maximizes the number of feasible allocation sequences under the constraints of the maximum tolerated imbalance and the allocation sequence length. It assigns an equal probability to all feasible sequences. However, its implementation is not easy due to th...

journal_title：Statistical methods in medical research

authors： Zhao W,Berger VW,Yu Z

更新日期：2018-07-01 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：:Post-therapeutic surveillance is one important component of cancer care. However, there still is no evidence-based strategies to schedule patients' follow-up examinations. Our approach is based on the modeling of the probability of the onset of relapse at an early asymptotic or preclinical stage and its transition to ...

journal_title：Statistical methods in medical research

authors： Somda SM,Leconte E,Boher JM,Asselain B,Kramar A,Filleron T

更新日期：2016-12-01 00:00:00

abstract：:With the emergence of rich information on biomarkers after treatments, new types of prognostic tools are being developed: dynamic prognostic tools that can be updated at each new biomarker measurement. Such predictions are of interest in oncology where after an initial treatment, patients are monitored with repeated b...

journal_title：Statistical methods in medical research

authors： Sène M,Taylor JM,Dignam JJ,Jacqmin-Gadda H,Proust-Lima C

更新日期：2016-12-01 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：:This article aims to develop a probability-based model involving the use of direct likelihood formulation and generalised linear modelling (GLM) approaches useful in estimating important disease parameters from longitudinal or repeated measurement data. The current application is based on infection with respiratory sy...

journal_title：Statistical methods in medical research

authors： Mwambi H,Ramroop S,White Lj,Okiro E,Nokes Dj,Shkedy Z,Molenberghs G

更新日期：2011-10-01 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：: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 three-class Youden index serves both as a measure of medical test accuracy and a criterion to choose the optimal pair of cutoff values for classifying subjects into three ordinal disease categories (e.g. no disease, mild disease, advanced disease). We present a Bayesian nonparametric approach for estimating the th...

journal_title：Statistical methods in medical research

authors： Carvalho VI,Branscum AJ

更新日期：2018-03-01 00:00:00

abstract：:In this study, we discuss a decision theoretic or fully Bayesian approach to the sample size question in clinical trials with binary responses. Data are assumed to come from two binomial distributions. A Dirichlet distribution is assumed to describe prior knowledge of the two success probabilities p1 and p2. The param...

journal_title：Statistical methods in medical research

authors： Pezeshk H,Nematollahi N,Maroufy V,Marriott P,Gittins J

更新日期：2013-12-01 00:00:00