Joint modeling of repeated multivariate cognitive measures and competing risks of dementia and death: a latent process and latent class approach.

abstract：:To compare the survival functions based on right-truncated data, Lagakos et al. proposed a weighted logrank test based on a reverse time scale. This is in contrast to Bilker and Wang, who suggested a semi-parametric version of the Mann-Whitney test by assuming that the distribution of truncation times is known or can ...

journal_title：Statistics in medicine

authors： Chi Y,Tsai WY,Chiang CL

更新日期：2007-02-20 00:00:00

abstract：:Novel methodology is implemented to assess the predictive power of covariate information associated with sequential binary events. Logistic models are first fitted on the basis of a subset of the observations and then evaluated sequentially on the rest. The probabilistic forecasts are compared to the outcomes via a sc...

journal_title：Statistics in medicine

authors： Seillier-Moiseiwitsch F

更新日期：1996-10-30 00:00:00

abstract：:We suggest measures to quantify the degrees of necessity and of sufficiency of prognostic factors for dichotomous and for survival outcomes. A cause, represented by certain values of prognostic factors, is considered necessary for an event if, without the cause, the event cannot develop. It is considered sufficient fo...

journal_title：Statistics in medicine

authors： Gleiss A,Schemper M

更新日期：2019-10-15 00:00:00

abstract：:Existing methods for power analysis for longitudinal study designs are limited in that they do not adequately address random missing data patterns. Although the pattern of missing data can be assessed during data analysis, it is unknown during the design phase of a study. The random nature of the missing data pattern ...

journal_title：Statistics in medicine

authors： Tu XM,Zhang J,Kowalski J,Shults J,Feng C,Sun W,Tang W

更新日期：2007-07-10 00:00:00

abstract：:This paper discusses design considerations and the role of randomization-based inference in randomized community intervention trials. We stress that longitudinal follow-up of cohorts within communities often yields useful information on the effects of intervention on individuals, whereas cross-sectional surveys can us...

journal_title：Statistics in medicine

authors： Gail MH,Mark SD,Carroll RJ,Green SB,Pee D

更新日期：1996-06-15 00:00:00

abstract：:A Non-Parametric Maximum Likelihood approach to the estimation of relative risks in the context of disease mapping is discussed and a NPML approximation to conditional autoregressive models is proposed. NPML estimates have been compared to other proposed solutions (Maximum Likelihood via Monte Carlo Scoring, Hierarchi...

journal_title：Statistics in medicine

authors： Biggeri A,Marchi M,Lagazio C,Martuzzi M,Böhning D

更新日期：2000-09-15 00:00:00

abstract：:Appropriate quantification of added usefulness offered by new markers included in risk prediction algorithms is a problem of active research and debate. Standard methods, including statistical significance and c statistic are useful but not sufficient. Net reclassification improvement (NRI) offers a simple intuitive w...

journal_title：Statistics in medicine

authors： Pencina MJ,D'Agostino RB Sr,Steyerberg EW

更新日期：2011-01-15 00:00:00

abstract：:Propensity score analysis is widely used in observational studies to adjust for confounding and estimate the causal effect of a treatment on the outcome. When the outcome is survival time, there are special considerations on the definition of the causal estimand, point, and variance estimation that have not been thoro...

journal_title：Statistics in medicine

authors： Mao H,Li L,Yang W,Shen Y

更新日期：2018-11-20 00:00:00

abstract：:Meta-analyses pooling continuous outcomes can use mean differences (MD), standardized MD (MD in pooled standard deviation units, SMD), or ratio of arithmetic means (RoM). Recently, ratio of geometric means using ad hoc (RoGM (ad hoc) ) or Taylor series (RoGM (Taylor) ) methods for estimating variances have been propos...

journal_title：Statistics in medicine

authors： Friedrich JO,Adhikari NK,Beyene J

更新日期：2012-07-30 00:00:00

abstract：:Statistical modeling methods have had increasing use in drug disposition studies, both to estimate pharmacokinetic parameters and to develop regression models that relate these parameter estimates to patient characteristics. These methods are particularly flexible as they allow non-linearity and sparse within-patient ...

journal_title：Statistics in medicine

authors： Roe DJ

更新日期：1997-06-15 00:00:00

abstract：:In many practical applications, count data often exhibit greater or less variability than allowed by the equality of mean and variance, referred to as overdispersion/underdispersion, and there are several reasons that may lead to the overdispersion/underdispersion such as zero inflation and mixture. Moreover, if the c...

journal_title：Statistics in medicine

authors： Chen XD,Fu YZ,Wang XR

更新日期：2013-04-15 00:00:00

abstract：:In psychiatry, clinicians use criteria sets from the Diagnostic and Statistical Manual of Mental Disorders to diagnose mental disorders. Most criteria sets have several symptom domains, and in order to be diagnosed, an individual must meet the minimum number of symptoms required by each domain. Some efforts are now fo...

journal_title：Statistics in medicine

authors： Mauro C,Shear MK,Wang Y

更新日期：2019-07-20 00:00:00

abstract：:In a recent Statistics in Medicine paper, Warn, Thompson and Spiegelhalter (WTS) made a comparison between the Bayesian approach to the meta-analysis of binary outcomes and a popular Classical approach that uses summary (two-stage) techniques. They included approximate summary (two-stage) Bayesian techniques in their ...

journal_title：Statistics in medicine

authors： O'Rourke K,Altman DG

更新日期：2005-09-15 00:00:00

abstract：:We study the group bridge and the adaptive group bridge penalties for competing risks quantile regression with group variables. While the group bridge consistently identifies nonzero group variables, the adaptive group bridge consistently selects variables not only at group level but also at within-group level. We all...

journal_title：Statistics in medicine

authors： Ahn KW,Kim S

更新日期：2018-04-30 00:00:00

abstract：:Delay in the outcome variable is challenging for outcome-adaptive randomization, as it creates a lag between the number of subjects accrued and the information known at the time of the analysis. Motivated by a real-life pediatric ulcerative colitis trial, we consider a case where a short-term predictor is available fo...

journal_title：Statistics in medicine

authors： Kim MO,Liu C,Hu F,Lee JJ

更新日期：2014-10-15 00:00:00

abstract：:In randomised trials, continuous endpoints are often measured with some degree of error. This study explores the impact of ignoring measurement error and proposes methods to improve statistical inference in the presence of measurement error. Three main types of measurement error in continuous endpoints are considered:...

journal_title：Statistics in medicine

authors： Nab L,Groenwold RHH,Welsing PMJ,van Smeden M

更新日期：2019-11-30 00:00:00

abstract：:Misclassification introduces errors in categorical variables. This paper presents a review of methods for misclassified categorical data in epidemiology. Different sampling schemes for a 2 x 2 x 2 table and methods of analyses will be discussed first. A misclassification matrix is defined, and the usual misclassificat...

journal_title：Statistics in medicine

authors： Chen TT

更新日期：1989-09-01 00:00:00

abstract：:Clinical studies that involve the recording of two or more distinct and well-defined events on each subject give rise to multiple event data. Treatment comparisons are usually reported in univariate analyses of time to first event or number of events observed. However, this approach may not uncover the 'full story' of...

journal_title：Statistics in medicine

authors： Barai U,Teoh N

更新日期：1997-04-30 00:00:00

abstract：:Down's syndrome screening is currently carried out using a combination of biochemical markers measured in maternal serum samples; these include MSAFP, Total hCG, uE3 and Free beta-hCG. Recently a number of papers have compared the effectiveness of different combinations of these markers. Some recommend MSAFP, Total hC...

journal_title：Statistics in medicine

authors： Dunstan FD,Gray JC,Nix AB,Reynolds T

更新日期：1997-07-15 00:00:00

abstract：:Technologic advances give rise to new tests for detecting disease in many fields, including cancer and sexually transmitted disease. Before a new disease screening test is approved for public use, its accuracy should be shown to be better than or at least not inferior to an existing test. Standards do not yet exist fo...

journal_title：Statistics in medicine

authors： Alonzo TA,Pepe MS,Moskowitz CS

更新日期：2002-03-30 00:00:00

abstract：:In this paper we study the problem of variable selection for the proportional odds model, which is a useful alternative to the proportional hazards model and might be appropriate when the proportional hazards assumption is not satisfied. We propose to fit the proportional odds model by maximizing the marginal likeliho...

journal_title：Statistics in medicine

authors： Lu W,Zhang HH

更新日期：2007-09-10 00:00:00

abstract：:Regression to the mean arises often in statistical applications where the units chosen for study relate to some observed characteristic in the extreme of its distribution. Gardner and Heady attribute the effect of regression to the mean to measurement errors. They assume the model Yi = U + ei, where U is a fixed withi...

journal_title：Statistics in medicine

authors： Johnson WD,George VT

更新日期：1991-08-01 00:00:00

abstract：:We present graphical and numerical methods for assessing the adequacy of the logistic regression model for stratified case-control data. The proposed methods are derived from the cumulative sum of residuals over the covariate or linear predictor. Under the assumed model, the cumulative residual process converges weakl...

journal_title：Statistics in medicine

authors： Arbogast PG,Lin DY

更新日期：2005-01-30 00:00:00

abstract：:Adaptive designs or flexible designs in a broader sense have increasingly been considered in planning pivotal registration clinical trials. Sample size reassessment design and adaptive selection design are two of such designs that appear in regulatory applications. At the design stage, consideration of sample size rea...

journal_title：Statistics in medicine

authors： Hung HM,Wang SJ,O'Neill R

更新日期：2011-06-15 00:00:00

abstract：:Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the c...

journal_title：Statistics in medicine

authors： Lachin JM

更新日期：2005-09-30 00:00:00

abstract：:Patients who switch treatment groups in randomized clinical trials can cause problems in the interpretation of the results. Although the intention-to-treat method is recognized as being the most reliable analysis, it may result in an underestimate of the treatment effect if there have been patients who switch treatmen...

journal_title：Statistics in medicine

authors： Law MG,Kaldor JM

更新日期：1996-10-15 00:00:00

abstract：:In this paper we describe Bonferroni-based multiple testing procedures (MTPs) as strategies to split and recycle test mass. Here, 'test mass' refers to (parts of) the nominal level alpha at which the family-wise error rate is controlled. Briefly, test mass is split between different null hypotheses, and whenever a nul...

journal_title：Statistics in medicine

authors： Burman CF,Sonesson C,Guilbaud O

更新日期：2009-02-28 00:00:00

abstract：:Proportional odds regression models for multinomial probabilities based on ordered categories have been generalized in two somewhat different directions. Models having scale as well as location parameters for adjustment of boundaries (on an unobservable, underlying continuum) between categories have been employed in t...

journal_title：Statistics in medicine

authors： Cox C

更新日期：1995-06-15 00:00:00

abstract：:Among many other uses, positron emission tomography (PET) can be used in studies to estimate the density of a neuroreceptor at each location throughout the brain by measuring the concentration of a radiotracer over time and modeling its kinetics. There are a variety of kinetic models in common usage and these typicall...

journal_title：Statistics in medicine

authors： Chang C,Ogden RT

更新日期：2009-03-15 00:00:00

abstract：:Assay sensitivity has been proposed as a criterion for including psychiatric clinical outcome studies in meta-analyses. The authors assess the performance of assay sensitivity as a method for determining study appropriateness for meta-analysis by calculating expected standard drug vs placebo effect sizes for various c...

journal_title：Statistics in medicine

authors： Gelfand LA,Strunk DR,Tu XM,Noble RE,Derubeis RJ

更新日期：2006-03-30 00:00:00