A threshold-free summary index of prediction accuracy for censored time to event data.

abstract：:A new method is proposed for the surveillance of Down's syndrome among newborn. Despite the strong dependence of overall risk of Down's syndrome on maternal age, it has been suggested that an environmentally induced increase in risk may be additive over all maternal ages. The surveillance method introduced here is spe...

journal_title：Statistics in medicine

authors： Lie RT,Heuch I,Irgens LM

更新日期：1993-01-15 00:00:00

abstract：:In medical research, a two-phase study is often used for the estimation of the area under the receiver operating characteristic curve (AUC) of a diagnostic test. However, such a design introduces verification bias. One of the methods to correct verification bias is inverse probability weighting (IPW). Since the probab...

journal_title：Statistics in medicine

authors： Wu Y

更新日期：2020-11-30 00:00:00

abstract：:Clinical trials with multiple endpoints incur increased familywise type I errors. The Bonferroni correction is a common method used to modify the p-values to account for multiple significance testing. For independent endpoints the Bonferroni method is slightly conservative whereas with high correlation the conservatis...

journal_title：Statistics in medicine

authors： James S

更新日期：1991-07-01 00:00:00

abstract：:We present some practical extensions and applications of a strategy proposed by Thall, Simon and Estey for designing and monitoring single-arm clinical trials with multiple outcomes. We show by application how the strategy may be applied to construct designs for phase IIA activity trials and phase II equivalence trial...

journal_title：Statistics in medicine

authors： Thall PF,Sung HG

更新日期：1998-07-30 00:00:00

abstract：:The goal of phase I cancer trials is to determine the highest dose of a treatment regimen with an acceptable toxicity rate. Traditional designs for phase I trials, such as the Continual Reassessment Method (CRM) and the 3 + 3 design, require each patient or a cohort of patients to be fully evaluated for the dose-limit...

journal_title：Statistics in medicine

authors： Polley MY

更新日期：2011-07-30 00:00:00

abstract：:The use of both sequential designs and adaptive treatment allocation are effective in reducing the number of patients receiving an inferior treatment in a clinical trial. In large samples, when the asymptotic normality of test statistics can be utilized, a standard sequential design can be combined with adaptive alloc...

journal_title：Statistics in medicine

authors： Stallard N,Rosenberger WF

更新日期：2002-02-28 00:00:00

abstract：:Genetic markers can be used as instrumental variables, in an analogous way to randomization in a clinical trial, to estimate the causal relationship between a phenotype and an outcome variable. Our purpose is to extend the existing methods for such Mendelian randomization studies to the context of multiple genetic mar...

journal_title：Statistics in medicine

authors： Burgess S,Thompson SG,CRP CHD Genetics Collaboration.,Burgess S,Thompson SG,Andrews G,Samani NJ,Hall A,Whincup P,Morris R,Lawlor DA,Davey Smith G,Timpson N,Ebrahim S,Ben-Shlomo Y,Davey Smith G,Timpson N,Brown M,Ricket

更新日期：2010-05-30 00:00:00

abstract：:Cancer immunotherapy trials have two special features: a delayed treatment effect and a cure rate. Both features violate the proportional hazard model assumption and ignoring either one of the two features in an immunotherapy trial design will result in substantial loss of statistical power. To properly design immunot...

journal_title：Statistics in medicine

authors： Wei J,Wu J

更新日期：2020-03-15 00:00:00

abstract：:Pooling biospecimens prior to performing lab assays can help reduce lab costs, preserve specimens, and reduce information loss when subject to a limit of detection. Because many biomarkers measured in epidemiological studies are positive and right-skewed, proper analysis of pooled specimens requires special methods. I...

journal_title：Statistics in medicine

authors： Mitchell EM,Lyles RH,Schisterman EF

更新日期：2015-07-30 00:00:00

abstract：:It has been increasingly common to analyze simultaneously repeated measures and time to failure data. In this paper we propose a joint model when the repeated measures are semi-continuous, characterized by the presence of a large portion of zero values, as well as right skewness of non zero (positive) values. Examples...

journal_title：Statistics in medicine

authors： Liu L

更新日期：2009-03-15 00:00:00

abstract：:Intraclass correlation coefficient (ICC) estimates must be provided when reporting the results of a cluster randomized trial. This study demonstrates that estimating this parameter with one-way ANOVA and an underlying mixed-effects statistical model leads to biased estimates. The bias depends on the effect size of the...

journal_title：Statistics in medicine

authors： Giraudeau B

更新日期：2006-03-30 00:00:00

abstract：:With increasingly abundant spatial data in the form of case counts or rates combined over areal regions (eg, ZIP codes, census tracts, or counties), interest turns to formal identification of difference "boundaries," or barriers on the map, in addition to the estimated statistical map itself. "Boundary" refers to a bo...

journal_title：Statistics in medicine

authors： Guhaniyogi R

更新日期：2017-11-10 00:00:00

abstract：:This paper concerns using modified weighted Schoenfeld residuals to test the proportionality of subdistribution hazards for the Fine-Gray model, similar to the tests proposed by Grambsch and Therneau for independently censored data. We develop a score test for the time-varying coefficients based on the modified Schoen...

journal_title：Statistics in medicine

authors： Zhou B,Fine J,Laird G

更新日期：2013-09-30 00:00:00

abstract：:Two important qualities of controlled clinical trials are that they reduce dependence on historical standards for evaluating therapy and separate the effect of treatment from the confounding influence of time. Whatever the theory of the clinical trial, however, time has not easily been banished from the analysis of me...

journal_title：Statistics in medicine

authors： Senn SJ

更新日期：1989-11-01 00:00:00

abstract：:We examine the properties of several tests for goodness-of-fit for multinomial logistic regression. One test is based on a strategy of sorting the observations according to the complement of the estimated probability for the reference outcome category and then grouping the subjects into g equal-sized groups. A g x c c...

journal_title：Statistics in medicine

authors： Fagerland MW,Hosmer DW,Bofin AM

更新日期：2008-09-20 00:00:00

abstract：:It is unclear to what extent the incremental predictive performance of a novel biomarker is impacted by the method used to control for standard predictors. We investigated whether adding a biomarker to a model with a published risk score overestimates its incremental performance as compared to adding it to a multivari...

journal_title：Statistics in medicine

authors： Xanthakis V,Sullivan LM,Vasan RS,Benjamin EJ,Massaro JM,D'Agostino RB Sr,Pencina MJ

更新日期：2014-07-10 00:00:00

abstract：:Before introducing a new measurement tool it is necessary to evaluate its performance. Several statistical methods have been developed, or used, to evaluate the reliability and validity of a new assessment method in such circumstances. In this paper we review some commonly used methods. Data from a study that was cond...

journal_title：Statistics in medicine

authors： White SA,van den Broek NR

更新日期：2004-05-30 00:00:00

abstract：:Many gene expression data are based on two experiments where the gene expressions of the targeted genes under both experiments are correlated. We consider problems in which objectives are to find genes that are simultaneously upregulated/downregulated under both experiments. A Bayesian methodology is proposed based on...

journal_title：Statistics in medicine

authors： Bansal NK,Jiang H,Pradeep P

更新日期：2015-11-10 00:00:00

abstract：:Cancer patients, chronic kidney disease patients, and subjects infected with HIV are routinely monitored over time using biomarkers that represent key health status indicators. Furthermore, biomarkers are frequently used to guide initiation of new treatments or to inform changes in intervention strategies. Since key m...

journal_title：Statistics in medicine

authors： Saha-Chaudhuri P,Heagerty PJ

更新日期：2018-08-15 00:00:00

abstract：:We consider the problem of comparing cumulative incidence functions of non-mortality events in the presence of informative coarsening and the competing risk of death. We extend frequentist-based hypothesis tests previously developed for non-informative coarsening and propose a novel Bayesian method based on comparing ...

journal_title：Statistics in medicine

authors： Shardell M,Scharfstein DO,Vlahov D,Galai N

更新日期：2008-12-10 00:00:00

abstract：:We applied a two-stage random effects model to pulmonary function data from 31 sarcoidosis patients to illustrate its usefulness in analysing unbalanced longitudinal data. For the first stage, repeated measurements of percentage of predicted forced vital capacity (FVC%) from an individual were modelled as a function o...

journal_title：Statistics in medicine

authors： Vacek PM,Mickey RM,Bell DY

更新日期：1989-02-01 00:00:00

abstract：:A personalized treatment strategy formalizes evidence-based treatment selection by mapping patient information to a recommended treatment. Personalized treatment strategies can produce better patient outcomes while reducing cost and treatment burden. Thus, among clinical and intervention scientists, there is a growing...

journal_title：Statistics in medicine

authors： Laber EB,Zhao YQ,Regh T,Davidian M,Tsiatis A,Stanford JB,Zeng D,Song R,Kosorok MR

更新日期：2016-04-15 00:00:00

abstract：:We compared eight nominal 95 per cent confidence intervals for the ratio of two Poisson parameters, both assumed small, on their true coverage (the probability that the interval includes the ratio of Poisson parameters) and median width. The commonly used log-linear interval, justified by asymptotic considerations, pr...

journal_title：Statistics in medicine

authors： Barker L,Cadwell BL

更新日期：2008-09-10 00:00:00

abstract：:Standard randomization-based tests of sharp null hypotheses in randomized clinical trials, that is, intent-to-treat analyses, are valid without extraneous assumptions, but generally can be appropriately powerful only with alternative hypotheses that involve treatment assignment having an effect on outcome. In the cont...

journal_title：Statistics in medicine

authors： Rubin DB

更新日期：1998-02-15 00:00:00

abstract：:In the last decade or so, pharmaceutical drug development activities in the area of new antibacterial drugs for treating serious bacterial diseases have declined, and at the same time, there are worries that the increased prevalence of antibiotic-resistant bacterial infections, especially the increase in drug-resistan...

journal_title：Statistics in medicine

authors： Huque MF,Valappil T,Soon GG

更新日期：2014-11-10 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：:The use of data from multiple studies or centers for the validation of a clinical test or a multivariable prediction model allows researchers to investigate the test's/model's performance in multiple settings and populations. Recently, meta-analytic techniques have been proposed to summarize discrimination and calibra...

journal_title：Statistics in medicine

authors： Wynants L,Riley RD,Timmerman D,Van Calster B

更新日期：2018-05-30 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：:Performance of a diagnostic test is ideally evaluated by a comparison of the test results to a gold standard for all the patients in a study. In practice, however, it is common for a subset of study patients to have the gold standard not verified (missing) due to ethical or expense considerations. Sensitivity and spec...

journal_title：Statistics in medicine

authors： Kosinski AS,Chen Y,Lyles RH

更新日期：2010-07-10 00:00:00

abstract：:For each of 211 arteriosclerosis obliterans patients, the degree of stenosis of arteries at four sites were examined at Hiroshima University Hospital to analyse the relationship between the degree of stenosis and age, sex and site. The generalized estimating equations using a proportional odds model for the stenosis p...

journal_title：Statistics in medicine

authors： Nakashima E,Tsuji S,Fukuoka H,Ohtaki M,Ito K

更新日期：2003-07-15 00:00:00