Pattern discovery of health curves using an ordered probit model with Bayesian smoothing and functional principal component analysis.

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 mixed effects model for repeated measures has been widely used for the analysis of longitudinal clinical data collected at a number of fixed time points. We propose a robust extension of the mixed effects model for repeated measures for skewed and heavy-tailed data on basis of the multivariate skew-t distribution,...

journal_title：Statistical methods in medical research

authors： Tang Y

更新日期：2020-06-01 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：: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：:The use of genetic variants as instrumental variables - an approach known as Mendelian randomization - is a popular epidemiological method for estimating the causal effect of an exposure (phenotype, biomarker, risk factor) on a disease or health-related outcome from observational data. Instrumental variables must sati...

journal_title：Statistical methods in medical research

authors： Bucur IG,Claassen T,Heskes T

更新日期：2020-04-01 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：: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：:This article discusses and extends statistical models to jointly analyse the spatial variation of rates of several diseases with common risk factors. We start with a review of methods for separate analyses of diseases, then move to ecological regression approaches, where the rates from one of the diseases enter as sur...

journal_title：Statistical methods in medical research

authors： Held L,Natário I,Fenton SE,Rue H,Becker N

更新日期：2005-02-01 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

abstract：:When comparing two different kinds of group therapy or two individual treatments where patients within each arm are nested within care providers, clustering of observations may occur in both arms. The arms may differ in terms of (a) the intraclass correlation, (b) the outcome variance, (c) the cluster size, and (d) th...

journal_title：Statistical methods in medical research

authors： Candel MJ,van Breukelen GJ

更新日期：2015-10-01 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：: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：:Identification of cancer patient subgroups using high throughput genomic data is of critical importance to clinicians and scientists because it can offer opportunities for more personalized treatment and overlapping treatments of cancers. In spite of tremendous efforts, this problem still remains challenging because o...

journal_title：Statistical methods in medical research

authors： Wei W,Sun Z,da Silveira WA,Yu Z,Lawson A,Hardiman G,Kelemen LE,Chung D

更新日期：2019-07-01 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：: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：:Tracking a subject's risk factors or health status over time is an important objective in long-term epidemiological studies with repeated measurements. An important issue of time-trend tracking is to define appropriate statistical indices to quantitatively measure the tracking abilities of the targeted risk factors or...

journal_title：Statistical methods in medical research

authors： Wu CO,Tian X,Tian L,Reis JP,Zhao L,Allen NB,Bae S,Liu K

更新日期：2020-02-01 00:00:00

abstract：:Covariate-adaptive designs are widely used to balance covariates and maintain randomization in clinical trials. Adaptive designs for discrete covariates and their asymptotic properties have been well studied in the literature. However, important continuous covariates are often involved in clinical studies. Simply disc...

journal_title：Statistical methods in medical research

authors： Li X,Zhou J,Hu F

更新日期：2019-06-01 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：: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：: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：:Joint models for recurrent and terminal events have not been yet developed for clustered data. The goals of our study are to develop a statistical framework for modelling clustered recurrent and terminal events and to perform dynamic predictions of the terminal event in family studies. We propose a joint nested frailt...

journal_title：Statistical methods in medical research

authors： Choi YH,Jacqmin-Gadda H,Król A,Parfrey P,Briollais L,Rondeau V

更新日期：2020-05-01 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：:We propose a flexible and computationally efficient penalized estimation method for a semi-parametric linear transformation model with current status data. To facilitate model fitting, the unknown monotone function is approximated by monotone B-splines, and a computationally efficient hybrid algorithm involving the Fi...

journal_title：Statistical methods in medical research

authors： Lu M,Liu Y,Li CS

更新日期：2020-01-01 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：: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：: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：:We propose a cross-validated area under the receiving operator characteristic (ROC) curve (CV-AUC) criterion for tuning parameter selection for penalized methods in sparse, high-dimensional logistic regression models. We use this criterion in combination with the minimax concave penalty (MCP) method for variable selec...

journal_title：Statistical methods in medical research

authors： Jiang D,Huang J,Zhang Y

更新日期：2013-10-01 00:00:00

abstract：:The estimation of population parameters using complex survey data requires careful statistical modelling to account for the design features. This is further complicated by unit and item nonresponse for which a number of methods have been developed in order to reduce estimation bias. In this paper, we address some issu...

journal_title：Statistical methods in medical research

authors： Geraci M

更新日期：2016-08-01 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：: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