A two-stage experimental design for dilution assays.

abstract：:Image-on-image regression analysis, using images to predict images, is a challenging task, due to (1) the high dimensionality and (2) the complex spatial dependence structures in image predictors and image outcomes. In this work, we propose a novel image-on-image regression model, by extending a spatial Bayesian laten...

journal_title：Biometrics

authors： Guo C,Kang J,Johnson TD

更新日期：2020-12-27 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：:Pharmaceutical products are routinely monitored for their stability over time. Stability studies generally consist of a random sample of dosage units (e.g., tablets, capsules, vials) from a batch or several batches placed in a storage room and periodically assayed for their drug content. The degradation of the drug pr...

journal_title：Biometrics

authors： Ruberg SJ,Stegeman JW

更新日期：1991-09-01 00:00:00

abstract：:The estimation of gene frequencies, linkage disequilibrium and disease associations for the human leukocyte antigen (HLA) system is considered. Comprehensive models for HLA data are introduced and contrasted with simpler approaches to the analysis of such data. ...

journal_title：Biometrics

authors： Farewell VT,Dahlberg S

更新日期：1984-06-01 00:00:00

abstract：:We propose a Bayesian latent Ornstein-Uhlenbeck (OU) model to analyze unbalanced longitudinal data of binary and ordinal variables, which are manifestations of fewer continuous latent variables. We focus on the evolution of such latent variables when they continuously change over time. Existing approaches are limited ...

journal_title：Biometrics

authors： Tran TD,Lesaffre E,Verbeke G,Duyck J

更新日期：2020-05-11 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：:This paper presents the development, application and evaluation of a stochastic model of the frequency of occurrence of transient ischemic attacks (TIAs). TIAs occur during periods of abnormal arterial activity. The TIAs which occur during a single period of abnormal activity are called a cluster of TIAs. Thus, the nu...

journal_title：Biometrics

authors： Dunn JK,Hardy RJ

更新日期：1980-03-01 00:00:00

abstract：:A likelihood ratio statistic is proposed for testing goodness of fit with grouped data which are subject to random right censoring. It is shown that, under appropriate conditions, this statistic has an asymptotic chi-square distribution which is non-central under contiguous alternatives. A formula is given for the non...

journal_title：Biometrics

authors： Turnbull BW,Weiss L

更新日期：1978-09-01 00:00:00

abstract：:Dynamic treatment regimes (DTRs) aim to formalize personalized medicine by tailoring treatment decisions to individual patient characteristics. G-estimation for DTR identification targets the parameters of a structural nested mean model, known as the blip function, from which the optimal DTR is derived. Despite its po...

journal_title：Biometrics

authors： Wallace MP,Moodie EEM,Stephens DA

更新日期：2019-12-01 00:00:00

abstract：:In many applications of generalized linear mixed models to multilevel data, it is of interest to test whether a random effects variance component is zero. It is well known that the usual asymptotic chi-square distribution of the likelihood ratio and score statistics under the null does not necessarily hold. In this no...

journal_title：Biometrics

authors： Fitzmaurice GM,Lipsitz SR,Ibrahim JG

更新日期：2007-09-01 00:00:00

abstract：:Genetic variants associated with disease outcomes can be used to develop personalized treatment. To reach this precision medicine goal, hundreds of large-scale genome-wide association studies (GWAS) have been conducted in the past decade to search for promising genetic variants associated with various traits. They hav...

journal_title：Biometrics

authors： Masotti M,Guo B,Wu B

更新日期：2019-12-01 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

abstract：:We study publication bias in meta-analysis by supposing there is a population (y, sigma) of studies which give treatment effect estimates y approximately N(theta, sigma(2)). A selection function describes the probability that each study is selected for review. The overall estimate of theta depends on the studies selec...

journal_title：Biometrics

authors： Henmi M,Copas JB,Eguchi S

更新日期：2007-06-01 00:00:00

abstract：:Inference regarding the inclusion or exclusion of random effects in linear mixed models is challenging because the variance components are located on the boundary of their parameter space under the usual null hypothesis. As a result, the asymptotic null distribution of the Wald, score, and likelihood ratio tests will ...

journal_title：Biometrics

authors： Lee OE,Braun TM

更新日期：2012-06-01 00:00:00

abstract：:A nonparametric maximum likelihood procedure is given for estimating the survivor function from right-censored data. It approximates the hazard rate by a simple function such as a spline, with different approximations yielding different estimators. A special case is that proposed by Nelson (1969, Journal of Quality Te...

journal_title：Biometrics

authors： Whittemore AS,Keller JB

更新日期：1986-09-01 00:00:00

abstract：:Because the number of patients waiting for organ transplants exceeds the number of organs available, a better understanding of how transplantation affects the distribution of residual lifetime is needed to improve organ allocation. However, there has been little work to assess the survival benefit of transplantation f...

journal_title：Biometrics

authors： Vock DM,Tsiatis AA,Davidian M,Laber EB,Tsuang WM,Finlen Copeland CA,Palmer SM

更新日期：2013-12-01 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 extend the Mantel-Haenszel estimating function to estimate both the intra-cluster pairwise correlation and the main effects for sparse clustered binary data. We propose both a composite likelihood approach and an estimating function approach for the analysis of such data. The proposed estimators are consistent and ...

journal_title：Biometrics

authors： Wang M,Williamson JM

更新日期：2005-12-01 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：:This article demonstrates semiparametric maximum likelihood estimation of a nonlinear growth model for fish lengths using imprecisely measured ages. Data on the species corvina reina, found in the Gulf of Nicoya, Costa Rica, consist of lengths and imprecise ages for 168 fish and precise ages for a subset of 16 fish. T...

journal_title：Biometrics

authors： Suh EY,Schafer DW

更新日期：2002-06-01 00:00:00

abstract：:Serial dilution assays are widely employed for estimating substance concentrations and minimum inhibitory concentrations. The Poisson-Bernoulli model for such assays is appropriate for count data but not for continuous measurements that are encountered in applications involving substance concentrations. This paper pre...

journal_title：Biometrics

authors： Lee ML,Whitmore GA

更新日期：1999-12-01 00:00:00

abstract：:The problem of regression dilution arising from covariate measurement error is investigated for survival data using the proportional hazards model. The naive approach to parameter estimation is considered whereby observed covariate values are used, inappropriately, in the usual analysis instead of the underlying covar...

journal_title：Biometrics

authors： Hughes MD

更新日期：1993-12-01 00:00:00

abstract：:Whether the aim is to diagnose individuals or estimate prevalence, many epidemiological studies have demonstrated the successful use of tests on pooled sera. These tests detect whether at least one sample in the pool is positive. Although originally designed to reduce diagnostic costs, testing pools also lowers false ...

journal_title：Biometrics

authors： Vansteelandt S,Goetghebeur E,Verstraeten T

更新日期：2000-12-01 00:00:00

abstract：:In this article, we study nonparametric estimation of the mean function of a counting process with panel observations. We introduce the gamma frailty variable to account for the intracorrelation between the panel counts of the counting process and construct a maximum pseudo-likelihood estimate with the frailty variabl...

journal_title：Biometrics

authors： Zhang Y,Jamshidian M

更新日期：2003-12-01 00:00:00

abstract：:The first part of the article reviews the Data Augmentation algorithm and presents two approximations to the Data Augmentation algorithm for the analysis of missing-data problems: the Poor Man's Data Augmentation algorithm and the Asymptotic Data Augmentation algorithm. These two algorithms are then implemented in the...

journal_title：Biometrics

authors： Wei GC,Tanner MA

更新日期：1991-12-01 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：:In a presentation of various methods for assessing the sensitivity of regression results to unmeasured confounding, Lin, Psaty, and Kronmal (1998, Biometrics54, 948-963) use a conditional independence assumption to derive algebraic relationships between the true exposure effect and the apparent exposure effect in a re...

journal_title：Biometrics

authors： Vanderweele TJ

更新日期：2008-06-01 00:00:00

abstract：SUMMARY:Many hormones are secreted in pulses. The pulsatile relationship between hormones regulates many biological processes. To understand endocrine system regulation, time series of hormone concentrations are collected. The goal is to characterize pulsatile patterns and associations between hormones. Currently each ...

journal_title：Biometrics

authors： Carlson NE,Johnson TD,Brown MB

更新日期：2009-06-01 00:00:00

abstract：:The distribution of health care payments to insurance plans has substantial consequences for social policy. Risk adjustment formulas predict spending in health insurance markets in order to provide fair benefits and health care coverage for all enrollees, regardless of their health status. Unfortunately, current risk ...

journal_title：Biometrics

authors： Zink A,Rose S

更新日期：2020-09-01 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