Pleiotropy informed adaptive association test of multiple traits using genome-wide association study summary data.

abstract：:We propose group sequential tests of the equivalence of two treatments based on ideas related to repeated confidence intervals. These tests adapt readily to unpredictable group sizes, to the possibility of continuing even though a boundary has been crossed, and to nonnormal observations. In comparing two binomial dist...

journal_title：Biometrics

authors： Jennison C,Turnbull BW

更新日期：1993-03-01 00:00:00

abstract：:A general formula for the frequency of different recombinant gamete types, in terms of the underlying distribution of crossovers, is derived. This formula may be applied to any theoretical model of recombination in which it is assumed that there is no chromatid interference. Multiple-locus recombination data may be ev...

journal_title：Biometrics

authors： Risch N,Lange K

更新日期：1983-12-01 00:00:00

abstract：:We consider hidden Markov models as a versatile class of models for weakly dependent random phenomena. The topic of the present paper is likelihood-ratio testing for hidden Markov models, and we show that, under appropriate conditions, the standard asymptotic theory of likelihood-ratio tests is valid. Such tests are c...

journal_title：Biometrics

authors： Giudici P,Rydén T,Vandekerkhove P

更新日期：2000-09-01 00:00:00

abstract：:In this article, we demonstrate a statistical method for fitting the parameters of a sophisticated network and epidemic model to disease data. The pattern of contacts between hosts is described by a class of dyadic independence exponential-family random graph models (ERGMs), whereas the transmission process that runs ...

journal_title：Biometrics

authors： Groendyke C,Welch D,Hunter DR

更新日期：2012-09-01 00:00:00

abstract：:Differential equations are extensively used for modeling dynamics of physical processes in many scientific fields such as engineering, physics, and biomedical sciences. Parameter estimation of differential equation models is a challenging problem because of high computational cost and high-dimensional parameter space....

journal_title：Biometrics

authors： Wu H,Xue H,Kumar A

更新日期：2012-06-01 00:00:00

abstract：:We address one-sided stopping rules for clinical trials, or more generally, drug development programs, from a decision-theoretic point of view. If efficacy results are sufficiently negative then the trial will be stopped. But regardless of how positive the efficacy results are, the trial will continue in order to demo...

journal_title：Biometrics

authors： Berry DA,Ho CH

更新日期：1988-03-01 00:00:00

abstract：:We derive a likelihood score method for interval estimation of the intraclass version of the kappa coefficient of agreement with binary classification using a general theory of Bartlett (1953, Biometrika 40, 306-317). By exact evaluation, we investigate statistical properties of the score method, the chi-square goodne...

journal_title：Biometrics

authors： Nam JM

更新日期：2000-06-01 00:00:00

abstract：:We propose a new criterion for confounder selection when the underlying causal structure is unknown and only limited knowledge is available. We assume all covariates being considered are pretreatment variables and that for each covariate it is known (i) whether the covariate is a cause of treatment, and (ii) whether t...

journal_title：Biometrics

authors： VanderWeele TJ,Shpitser I

更新日期：2011-12-01 00:00:00

abstract：:We present a model for multivariate repeated measures that incorporates random effects, correlated stochastic processes, and measurement errors. The model is a multivariate generalization of the model for univariate longitudinal data given by Taylor, Cumberland, and Sy (1994, Journal of the American Statistical Associ...

journal_title：Biometrics

authors： Sy JP,Taylor JM,Cumberland WG

更新日期：1997-06-01 00:00:00

abstract：:In most research on smoothing splines the focus has been on estimation, while inference, especially hypothesis testing, has received less attention. By defining design matrices for fixed and random effects and the structure of the covariance matrices of random errors in an appropriate way, the cubic smoothing spline a...

journal_title：Biometrics

authors： Nummi T,Pan J,Siren T,Liu K

更新日期：2011-09-01 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：:We consider a two-sample problem where data come from symmetric distributions. Usual two-sample data with only magnitudes recorded, arising from case-control studies or logistic discriminant analyses, may constitute a symmetric two-sample problem. We propose a semiparametric model such that, in addition to symmetry, t...

journal_title：Biometrics

authors： Li M,Diao G,Qin J

更新日期：2020-12-01 00:00:00

abstract：:Population admixture can be a confounding factor in genetic association studies. Family-based methods (Rabinowitz and Larid, 2000, Human Heredity 50, 211-223) have been proposed in both testing and estimation settings to adjust for this confounding, especially in case-only association studies. The family-based methods...

journal_title：Biometrics

authors： Wang Y,Yang Q,Rabinowitz D

更新日期：2011-06-01 00:00:00

abstract：:Pocock et al. (2012, European Heart Journal 33, 176-182) proposed a win ratio approach to analyzing composite endpoints comprised of outcomes with different clinical priorities. In this article, we establish a statistical framework for this approach. We derive the null hypothesis and propose a closed-form variance est...

journal_title：Biometrics

authors： Luo X,Tian H,Mohanty S,Tsai WY

更新日期：2015-03-01 00:00:00

abstract：:Andersen et al. (1985, Biometrics 41, 921-932) gave an estimator of the cumulative relative mortality comparing rates of death in an epidemiologic cohort to an external population as a function of time when covariate information is available on all cohort members. We present an analogous estimator when covariate infor...

journal_title：Biometrics

authors： Borgan O,Langholz B

更新日期：1993-06-01 00:00:00

abstract：:Tsiatis, Rosner, and Mehta (1984, Biometrics 40, 797-803) proposed a procedure for constructing confidence intervals following group sequential tests of a normal mean. This method is first extended for group sequential tests for which the sample sizes between interim analyses are not identical or the times are not equ...

journal_title：Biometrics

authors： Kim K,DeMets DL

更新日期：1987-12-01 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：:Thanks to the growing interest in personalized medicine, joint modeling of longitudinal marker and time-to-event data has recently started to be used to derive dynamic individual risk predictions. Individual predictions are called dynamic because they are updated when information on the subject's health profile grows ...

journal_title：Biometrics

authors： Blanche P,Proust-Lima C,Loubère L,Berr C,Dartigues JF,Jacqmin-Gadda H

更新日期：2015-03-01 00:00:00

abstract：:Diggle and Kenward (1994, Applied Statistics 43, 49-93) proposed a selection model for continuous longitudinal data subject to nonrandom dropout. It has provoked a large debate about the role for such models. The original enthusiasm was followed by skepticism about the strong but untestable assumptions on which this t...

journal_title：Biometrics

authors： Verbeke G,Molenberghs G,Thijs H,Lesaffre E,Kenward MG

更新日期：2001-03-01 00:00:00

abstract：:The availability of data in longitudinal studies is often driven by features of the characteristics being studied. For example, clinical databases are increasingly being used for research to address longitudinal questions. Because visit times in such data are often driven by patient characteristics that may be related...

journal_title：Biometrics

authors： McCulloch CE,Neuhaus JM,Olin RL

更新日期：2016-12-01 00:00:00

abstract：:Statistical methods for the detection of genes influencing quantitative traits with the aid of genetic markers are well developed for normally distributed, fully observed phenotypes. Many experiments are concerned with failure-time phenotypes, which have skewed distributions and which are usually subject to censoring ...

journal_title：Biometrics

authors： Diao G,Lin DY

更新日期：2005-09-01 00:00:00

abstract：:Traditional studies of short-term air pollution health effects use time series data, while cohort studies generally focus on long-term effects. There is increasing interest in exploiting individual level cohort data to assess short-term health effects in order to understand the mechanisms and time scales of action. We...

journal_title：Biometrics

authors： Szpiro AA,Sheppard L,Adar SD,Kaufman JD

更新日期：2014-03-01 00:00:00

abstract：:Functional mapping is a useful tool for mapping quantitative trait loci (QTL) that control dynamic traits. It incorporates mathematical aspects of biological processes into the mixture model-based likelihood setting for QTL mapping, thus increasing the power of QTL detection and the precision of parameter estimation. ...

journal_title：Biometrics

authors： Yang J,Wu R,Casella G

更新日期：2009-03-01 00:00:00

abstract：:A time-dependent measure, termed the rate ratio, was proposed to assess the local dependence between two types of recurrent event processes in one-sample settings. However, the one-sample work does not consider modeling the dependence by covariates such as subject characteristics and treatments received. The focus of ...

journal_title：Biometrics

authors： Ning J,Cai C,Chen Y,Huang X,Wang MC

更新日期：2020-12-01 00:00:00

abstract：:The study of dynamical models of HIV infection, based on a system of nonlinear ordinary differential equations (ODE), has considerably improved the knowledge of its pathogenesis. While the first models used simplified ODE systems and analyzed each patient separately, recent works dealt with inference in non-simplified...

journal_title：Biometrics

authors： Guedj J,Thiébaut R,Commenges D

更新日期：2007-12-01 00:00:00

abstract：:The distance between homologous DNA sequences of two species is proposed to be -1/4 ln[det(P)], where P is the conditional probability matrix specifying the proportions of the various nucleotides in the second sequence, corresponding to each of the four nucleotides in the first sequence. A probability model is describ...

journal_title：Biometrics

authors： Barry D,Hartigan JA

更新日期：1987-06-01 00:00:00

abstract：:Gene-disease association studies based on case-control designs may often be used to identify candidate polymorphisms (markers) conferring disease risk. If a large number of markers are studied, genotyping all markers on all samples is inefficient in resource utilization. Here, we propose an alternative two-stage metho...

journal_title：Biometrics

authors： Satagopan JM,Venkatraman ES,Begg CB

更新日期：2004-09-01 00:00:00

abstract：:In a study designed to assess the relationship between a dichotomous exposure and the eventual occurrence of a dichotomous outcome, frequency matching has been proposed as a way to balance the exposure cohorts with respect to the sampling distribution of potential confounding factors. This paper discusses the pooled e...

journal_title：Biometrics

authors： Weinberg CR

更新日期：1985-03-01 00:00:00

abstract：:In an epidemiological study of risk factors in breast cancer, data are available on confirmed cases from a diagnostic clinic and on controls from a screening clinic that sampled the general population. Relative risk estimation is complicated by differences in the interviewing environment and in the wording and order o...

journal_title：Biometrics

authors： Elton RA,Duffy SW

更新日期：1983-09-01 00:00:00

abstract：:Heart rate oscillates in synchrony with respiration. Several methods have been employed to assess this 'sinus arrhythmia', as an index of autonomic nervous system function. This paper proposes a new, easily computed measure, R, which is relatively resistant to the major nonrespiratory sources of variation, including p...

journal_title：Biometrics

authors： Weinberg CR,Pfeifer MA

更新日期：1984-09-01 00:00:00