Correcting for the effect of misclassification bias in a case-control study using data from two different questionnaires.

abstract：:In this article, we present new methods to analyze data from an experiment using rodent models to investigate the role of p27, an important cell-cycle mediator, in early colon carcinogenesis. The responses modeled here are essentially functions nested within a two-stage hierarchy. Standard functional data analysis lit...

journal_title：Biometrics

authors： Baladandayuthapani V,Mallick BK,Young Hong M,Lupton JR,Turner ND,Carroll RJ

更新日期：2008-03-01 00:00:00

abstract：:A method is developed for obtaining tree-structured relative risk estimates for censored survival data. The first step of a full likelihood estimation procedure is used in a recursive partitioning algorithm that adopts most aspects of the widely used Classification and Regression Tree (CART) algorithm of Breiman et al...

journal_title：Biometrics

authors： LeBlanc M,Crowley J

更新日期：1992-06-01 00:00:00

abstract：:In this article, we propose approximate sample size formulas for establishing equivalence or noninferiority of two treatments in match-pairs design. Using the ratio of two proportions as the equivalence measure, we derive sample size formulas based on a score statistic for two types of analyses: hypothesis testing and...

journal_title：Biometrics

authors： Tang ML,Tang NS,Chan IS,Chan BP

更新日期：2002-12-01 00:00:00

abstract：:Jolliffe and Jolliffe (1997, Biometrics 53, 1136-1142) proposed various models for data from an experiment on memory in coal tits. This article describes an alternative model, which fits equally well and which may be simpler to interpret. ...

journal_title：Biometrics

authors： Ridout MS

更新日期：1999-06-01 00:00:00

abstract：:This paper considers methods for estimating the relationship between a binary response Y and the genetic effects responsible for a second binary trait Z. The responses Y are observed only for target individuals, and the responses Z are observed only for the relatives of these targets. The analysis consists of two part...

journal_title：Biometrics

authors： Houwing-Duistermaat JJ,van Houwelingen HC,de Winter JP

更新日期：2000-09-01 00:00:00

abstract：:An individual's health condition can affect the frequency and intensity of episodes that can occur repeatedly and that may be related to an event time of interest. For example, bleeding episodes during pregnancy may indicate problems predictive of preterm delivery. Motivated by this application, we propose a joint mod...

journal_title：Biometrics

authors： Herring AH,Yang J

更新日期：2007-06-01 00:00:00

abstract：:We consider a capture-recapture model in which capture probabilities vary with time and with behavioral response. Two inference procedures are developed under the assumption that recapture probabilities bear a constant relationship to initial capture probabilities. These two procedures are the maximum likelihood metho...

journal_title：Biometrics

authors： Chao A,Chu W,Hsu CH

更新日期：2000-06-01 00:00:00

abstract：:In the calibration problem, the need to construct a confidence interval to estimate the unknown chi 0 arises when the null hypothesis of zero slope is rejected. Otherwise, the resulting confidence interval will be infinite to reflect the fact that the slope of the regression line may be zero. Under the condition of re...

journal_title：Biometrics

authors： Lee JJ

更新日期：1991-12-01 00:00:00

abstract：:In problems with missing or latent data, a standard approach is to first impute the unobserved data, then perform all statistical analyses on the completed dataset--corresponding to the observed data and imputed unobserved data--using standard procedures for complete-data inference. Here, we extend this approach to mo...

journal_title：Biometrics

authors： Gelman A,Van Mechelen I,Verbeke G,Heitjan DF,Meulders M

更新日期：2005-03-01 00:00:00

abstract：:Estimation of treatment effects in randomized studies is often hampered by possible selection bias induced by conditioning on or adjusting for a variable measured post-randomization. One approach to obviate such selection bias is to consider inference about treatment effects within principal strata, that is, principal...

journal_title：Biometrics

authors： Long DM,Hudgens MG

更新日期：2013-12-01 00:00:00

abstract：:The class of admissible tests for Hardy-Weinberg equilibrium in a multi-allelic system is characterized. The standard goodness-of-fit chi-square tests is shown to be admissible for systems of two or more alleles. The conditional probability distribution required to determine the exact significance level of this test i...

journal_title：Biometrics

authors： Ledwina T,Gnot S

更新日期：1980-03-01 00:00:00

abstract：:Motivated by the particular problem of predicting defoliation based on a measure of gypsy moth egg mass density, prediction in the presence of measurement error is discussed. The measurement error variances and covariances are allowed to vary from unit to unit and are estimated by some type of within unit sampling. A ...

journal_title：Biometrics

authors： Buonaccorsi JP

更新日期：1995-12-01 00:00:00

abstract：:In studying the relationship between an ordered categorical predictor and an event time, it is standard practice to include dichotomous indicators of the different levels of the predictor in a Cox model. One can then use a multiple degree-of-freedom score or partial likelihood ratio test for hypothesis testing. Often,...

journal_title：Biometrics

authors： Dunson DB,Herring AH

更新日期：2003-12-01 00:00:00

abstract：:Bayesian experimental design for a clinical trial involves specifying a utility function that models the purpose of the trial, in this case the selection of patients for a diagnostic test. The best sample of patients is selected by maximizing expected utility. This optimization task poses difficulties due to a high-di...

journal_title：Biometrics

authors： Buzoianu M,Kadane JB

更新日期：2009-09-01 00:00:00

abstract：:A study of otitis media that requires a test for the comparison of two clustered samples of censored data is described. A method is proposed taking into account the within-subject correlation in the formation of the log-rank statistic. ...

journal_title：Biometrics

authors： Le CT,Lindgren BR

更新日期：1996-03-01 00:00:00

abstract：:Experiments that longitudinally collect RNA sequencing (RNA-seq) data can provide transformative insights in biology research by revealing the dynamic patterns of genes. Such experiments create a great demand for new analytic approaches to identify differentially expressed (DE) genes based on large-scale time-course c...

journal_title：Biometrics

authors： Cao M,Zhou W,Breidt FJ,Peers G

更新日期：2020-03-01 00:00:00

abstract：:We study the issue of identifiability of mixture models in the context of capture-recapture abundance estimation for closed populations. Such models are used to take account of individual heterogeneity in capture probabilities, but their validity was recently questioned by Link (2003, Biometrics 59, 1123-1130) on the ...

journal_title：Biometrics

authors： Holzmann H,Munk A,Zucchini W

更新日期：2006-09-01 00:00:00

abstract：:A recurring objective in longitudinal studies on aging and longevity has been the investigation of the relationship between age-at-death and current values of a longitudinal covariate trajectory that quantifies reproductive or other behavioral activity. We propose a novel technique for predicting age-at-death distribu...

journal_title：Biometrics

authors： Müller HG,Zhang Y

更新日期：2005-12-01 00:00:00

abstract：:Although the primary focus of Phase I clinical trials is to assess clinical pharmacology and possible toxicities, any information on the potential effect of treatment would be useful in helping to determine priorities between treatments for further study. We consider the scenario where data are routinely collected on ...

journal_title：Biometrics

authors： Lin HM,Hughes MD

更新日期：1995-09-01 00:00:00

abstract：:In multivariate survival analysis, investigators are often interested in testing for heterogeneity among clusters, both overall and within specific classes. We represent different hypotheses about the heterogeneity structure using a sequence of gamma frailty models, ranging from a null model with no random effects to ...

journal_title：Biometrics

authors： Dunson DB,Chen Z

更新日期：2004-06-01 00:00:00

abstract：SUMMARY:We develop sample size formulas for studies aiming to test mean differences between a treatment and control group when all-or-none nonadherence (noncompliance) and selection bias are expected. Recent work by Fay, Halloran, and Follmann (2007, Biometrics 63, 465-474) addressed the increased variances within grou...

journal_title：Biometrics

authors： Shardell MD,El-Kamary SS

更新日期：2009-06-01 00:00:00

abstract：:A method is proposed for calculating the probabilities of assignment of a patient to treatments; it involves minimizing a quadratic criterion subject to a balance constraint. The optimal probabilities are very easy to compute. Numerical illustration is given and comparisons are drawn with the entropy-based methods of ...

journal_title：Biometrics

authors： Titterington DM

更新日期：1983-12-01 00:00:00

abstract：:Prentice and Sheppard (1995, Biometrika 82, 113-125) proposed a method for estimating relative risks associated with poorly measured exposures using disease rates from multiple populations and exposure and confounding factor data from sample surveys of persons in each population. The method involved an assumption of i...

journal_title：Biometrics

authors： Anderson AB,Prentice RL

更新日期：1998-12-01 00:00:00

abstract：SUMMARY:We consider the analysis of clinical trials that involve randomization to an active treatment (T = 1) or a control treatment (T = 0), when the active treatment is subject to all-or-nothing compliance. We compare three approaches to estimating treatment efficacy in this situation: as-treated analysis, per-protoc...

journal_title：Biometrics

authors： Little RJ,Long Q,Lin X

更新日期：2009-06-01 00:00:00

abstract：:Estimating the number of clusters in a data set is a crucial step in cluster analysis. In this article, motivated by the gap method (Tibshirani, Walther, and Hastie, 2001, Journal of the Royal Statistical Society B63, 411-423), we propose the weighted gap and the difference of difference-weighted (DD-weighted) gap met...

journal_title：Biometrics

authors： Yan M,Ye K

更新日期：2007-12-01 00:00:00

abstract：:When testing the null hypothesis that treatment arm-specific survival-time distributions are equal, the log-rank test is asymptotically valid when the distribution of time to censoring is conditionally independent of randomized treatment group given survival time. We introduce a test of the null hypothesis for use whe...

journal_title：Biometrics

authors： DiRienzo AG

更新日期：2003-09-01 00:00:00

abstract：:High throughput technologies, such as gene expression arrays and protein mass spectrometry, allow one to simultaneously evaluate thousands of potential biomarkers that could distinguish different tissue types. Of particular interest here is distinguishing between cancerous and normal organ tissues. We consider statist...

journal_title：Biometrics

authors： Pepe MS,Longton G,Anderson GL,Schummer M

更新日期：2003-03-01 00:00:00

abstract：:In this note we propose a frailty model called piecewise gamma frailty for correlated survival data with random effects having a nested structure. In frailty models, a dependence function defined as a hazard ratio of one member given the failure time of another member in a unit is determined by the distributional assu...

journal_title：Biometrics

authors： Paik MC,Tsai WY,Ottman R

更新日期：1994-12-01 00:00:00

abstract：:A broad approach to the design of Phase I clinical trials for the efficient estimation of the maximum tolerated dose is presented. The method is rooted in formal optimal design theory and involves the construction of constrained Bayesian c- and D-optimal designs. The imposed constraint incorporates the optimal design ...

journal_title：Biometrics

authors： Haines LM,Perevozskaya I,Rosenberger WF

更新日期：2003-09-01 00:00:00

abstract：:This paper discusses interval estimation of the risk ratio (RR) between a secondary infection, given a primary infection, and the primary infection. Three asymptotic closed-form interval estimators are developed using Wald's test statistic, the logarithmic transformation, and Fieller's theorem. The performance of thes...

journal_title：Biometrics

authors： Lui KJ

更新日期：1998-06-01 00:00:00