Optimal designs when the variance is a function of the mean.

abstract：:The objective of this article is to develop a hypothesis-testing procedure to determine whether a common source outbreak has ended. We consider the case when neither the calendar date of exposure to the pathogen nor the exact incubation period distribution is known. The hypothesis-testing procedure is based on the spa...

journal_title：Biometrics

authors： Brookmeyer R,You X

更新日期：2006-03-01 00:00:00

abstract：:Asymptotic confidence bands for generalized nonlinear regression models are developed. These are based on a combination of the S method of Scheffe, together with the delta method which is used to approximate the mean function by a linear combination of the parameters. The approach can be used in any situation where la...

journal_title：Biometrics

authors： Cox C,Ma G

更新日期：1995-03-01 00:00:00

abstract：:For the analysis of time trends in incidence and mortality rates, the age-period-cohort (apc) model has became a widely accepted method. The considered data are arranged in a two-way table by age group and calendar period, which are mostly subdivided into 5- or 10-year intervals. The disadvantage of this approach is t...

journal_title：Biometrics

authors： Heuer C

更新日期：1997-03-01 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：:A method is presented for choosing an additive constant c when transforming data x to y = log(x + c). The method preserves Type I error probability and power in ANOVA under the assumption that the x + c for some c are log-normally distributed. The method has advantages similar to those of rank transformations--namely,...

journal_title：Biometrics

authors： Berry DA

更新日期：1987-06-01 00:00:00

abstract：:The aim of this study is to estimate incidence rates of onchocerciasis from skin-snip biopsies, based on incomplete data obtained in field surveys, with consideration of false negatives. The method of maximum likelihood is employed and the effect of false negatives on the incidence rates is discussed. ...

journal_title：Biometrics

authors： Yanagawa T,Kasagi F,Yoshimura T

更新日期：1984-06-01 00:00:00

abstract：:It is not, in general, possible to include all relevant risk factors in a model of survival or disease incidence. This heterogeneity must be accounted for in the interpretation, as it can imply otherwise unexpected results. This is illustrated by diabetic nephropathy, a serious complication experienced by some diabeti...

journal_title：Biometrics

authors： Hougaard P,Myglegaard P,Borch-Johnsen K

更新日期：1994-12-01 00:00:00

abstract：:Mixed longitudinal growth data consists of several observations on a characteristic over a limited age range for each individual in a study. This data is then combined to model growth over the total age range of all individuals in the study. The limited data collected on each individual precludes a subject-specific ap...

journal_title：Biometrics

authors： Huggins RM,Loesch DZ

更新日期：1998-06-01 00:00:00

abstract：:The objective of this paper is to develop statistical methods for estimating current and future numbers of individuals in different stages of the natural history of the human immunodeficiency (AIDS) virus infection and to evaluate the impact of therapeutic advances on these numbers. The approach is to extend the metho...

journal_title：Biometrics

authors： Brookmeyer R,Liao JG

更新日期：1990-12-01 00:00:00

abstract：:Johnson and Wehrly (1978, Journal of the American Statistical Association 73, 602-606) and Wehrly and Johnson (1980, Biometrika 67, 255-256) show one way to construct the joint distribution of a circular and a linear random variable, or the joint distribution of a pair of circular random variables from their marginal ...

journal_title：Biometrics

authors： Fernández-Durán JJ

更新日期：2007-06-01 00:00:00

abstract：:There has been great interest in developing nonlinear structural equation models and associated statistical inference procedures, including estimation and model selection methods. In this paper a general semiparametric structural equation model (SSEM) is developed in which the structural equation is composed of nonpar...

journal_title：Biometrics

authors： Guo R,Zhu H,Chow SM,Ibrahim JG

更新日期：2012-06-01 00:00:00

abstract：:In clinical trials and other investigations of survival time, information is often available on a time-dependent event other than survival. An example of such an auxiliary event in cancer studies is objective progression of disease. While some patients expire without experiencing objective disease progression, others ...

journal_title：Biometrics

authors： Lagakos SW

更新日期：1976-09-01 00:00:00

abstract：:In matched case-control studies one frequently must consider more than one variable in the analysis and in this paper a log-linear model is presented to meet this objective. A conditional argument yields a method for making inferences on the parameters measuring the association between the variables and disease. The r...

journal_title：Biometrics

authors： Holford TR

更新日期：1978-12-01 00:00:00

abstract：:In the context of state-space modeling, conventional usage of the deviance information criterion (DIC) evaluates the ability of the model to predict an observation at time t given the underlying state at time t. Motivated by the failure of conventional DIC to clearly choose between competing multivariate nonlinear Bay...

journal_title：Biometrics

authors： Millar RB,McKechnie S

更新日期：2014-12-01 00:00:00

abstract：:Unless the true association is very strong, simple large-sample confidence intervals for the odds ratio based on the delta method perform well even for small samples. Such intervals include the Woolf logit interval and the related Gart interval based on adding .5 before computing the log odds ratio estimate and its st...

journal_title：Biometrics

authors： Agresti A

更新日期：1999-06-01 00:00:00

abstract：:Dilution assays to determine solute concentration have found wide use in biomedical research. Many dilution assays return imprecise concentration estimates because they are only done to orders of magnitude. Previous statistical work has focused on how to design efficient experiments that can return more precise estima...

journal_title：Biometrics

authors： Ferguson JM,Miura TA,Miller CR

更新日期：2019-09-01 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：:Stepped wedge designed trials are a type of cluster-randomized study in which the intervention is introduced to each cluster in a random order over time. This design is often used to assess the effect of a new intervention as it is rolled out across a series of clinics or communities. Based on a permutation argument, ...

journal_title：Biometrics

authors： Hughes JP,Heagerty PJ,Xia F,Ren Y

更新日期：2020-03-01 00:00:00

abstract：:The basic problem under consideration is the comparison of treatments with respect to a response Y when a covariable X is taken into account. Various methods involving matching may be regarded as compromises between the standard analysis of covariance and the standard analysis of independent matched pairs. First, ther...

journal_title：Biometrics

authors： Quade D

更新日期：1982-09-01 00:00:00

abstract：:We describe a Bayesian quantile regression model that uses a confirmatory factor structure for part of the design matrix. This model is appropriate when the covariates are indicators of scientifically determined latent factors, and it is these latent factors that analysts seek to include as predictors in the quantile ...

journal_title：Biometrics

authors： Burgette LF,Reiter JP

更新日期：2012-03-01 00:00:00

abstract：:In this article, we propose a new statistical method-MutRSeq-for detecting differentially expressed single nucleotide variants (SNVs) based on RNA-seq data. Specifically, we focus on nonsynonymous mutations and employ a hierarchical likelihood approach to jointly model observed mutation events as well as read count me...

journal_title：Biometrics

authors： Fu R,Wang P,Ma W,Taguchi A,Wong CH,Zhang Q,Gazdar A,Hanash SM,Zhou Q,Zhong H,Feng Z

更新日期：2017-03-01 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：:A critical component of longitudinal study design involves determining the sampling schedule. Criteria for optimal design often focus on accurate estimation of the mean profile, although capturing the between-subject variance of the longitudinal process is also important since variance patterns may be associated with ...

journal_title：Biometrics

authors： Wu M,Diez-Roux A,Raghunathan TE,Sánchez BN

更新日期：2018-03-01 00:00:00

abstract：:Moment-based methods for analyzing repeated binary responses using the marginal odds ratio as a measure of association have been proposed by a number of authors. Carey, Zeger, and Diggle (1993, Biometrika 80, 517-526) have recently described how the marginal odds ratio can be estimated using generalized estimating equ...

journal_title：Biometrics

authors： Lipsitz SR,Fitzmaurice GM

更新日期：1996-09-01 00:00:00

abstract：:In sampling certain types of materials, such as bags of fertilizer, or subsampling large quantities of water, as might be done in investigating the density of plankton in certain environmental situations, it is customary to composite the samples. That is, several samples are drawn, mixed into a composite sample, and a...

journal_title：Biometrics

authors： Rohde CA

更新日期：1976-06-01 00:00:00

abstract：:When a true survival endpoint cannot be assessed for some subjects, an alternative endpoint that measures the true endpoint with error may be collected, which often occurs when obtaining the true endpoint is too invasive or costly. We develop an estimated likelihood function for the situation where we have both uncert...

journal_title：Biometrics

authors： Zee J,Xie SX

更新日期：2015-09-01 00:00:00

abstract：:The use of the uniformly most powerful among the unbiased (UMPU) test was recently suggested for the study of gametic association between two polymorphic loci as an alternative to the Fisher's exact test (Zapata and Alvarez, 1997, Annals of Human Genetics 61, 71-77). However, the proposed test is not UMPU for two-side...

journal_title：Biometrics

authors： Fuchs C

更新日期：2001-06-01 00:00:00

abstract：:We propose methods for Bayesian inference for a new class of semiparametric survival models with a cure fraction. Specifically, we propose a semiparametric cure rate model with a smoothing parameter that controls the degree of parametricity in the right tail of the survival distribution. We show that such a parameter ...

journal_title：Biometrics

authors： Ibrahim JG,Chen MH,Sinha D

更新日期：2001-06-01 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：: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