The proportional odds cumulative incidence model for competing risks.

abstract：:A topic of current biometric discussion is whether stratification should be used in randomized clinical trials and, if so, which kind. An approach based upon randomization theory is used to evaluate pre- versus post-stratification. The results obtained relate specifically to the effect of the size of the clinical tria...

journal_title：Biometrics

authors： McHugh R,Matts J

更新日期：1983-03-01 00:00:00

abstract：:Statistical models that include random effects are commonly used to analyze longitudinal and correlated data, often with the assumption that the random effects follow a Gaussian distribution. Via theoretical and numerical calculations and simulation, we investigate the impact of misspecification of this distribution o...

journal_title：Biometrics

authors： McCulloch CE,Neuhaus JM

更新日期：2011-03-01 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：:Recent developments in the animal breeding literature facilitate estimation of the variance components in quantitative genetic models. However, computation remains intensive, and many of the procedures are restricted to specialized designs and models, unsuited to data arising from studies of natural populations. We de...

journal_title：Biometrics

authors： Thompson EA,Shaw RG

更新日期：1990-06-01 00:00:00

abstract：:The method based on the Kolmogorov backward equations of Little (1995, Biometrics 51, 1278-1291) for computing hazard functions for the multistage carcinogenesis models fails when model parameters are time-dependent. In addition to suggesting an alternative method based on the Kolmogorov forward equation, this note hi...

journal_title：Biometrics

authors： Zheng Q

更新日期：1998-03-01 00:00:00

abstract：:Capture-recapture models are widely used to estimate demographic parameters of marked populations. Recently, this statistical theory has been extended to modeling dispersal of open populations. Multistate models can be used to estimate movement probabilities among subdivided populations if multiple sites are sampled. ...

journal_title：Biometrics

authors： Lindberg MS,Kendall WL,Hines JE,Anderson MG

更新日期：2001-03-01 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：:The standard approach to inference for random effects meta-analysis relies on approximating the null distribution of a test statistic by a standard normal distribution. This approximation is asymptotic on k, the number of studies, and can be substantially in error in medical meta-analyses, which often have only a few ...

journal_title：Biometrics

authors： Follmann DA,Proschan MA

更新日期：1999-09-01 00:00:00

abstract：:At any age the mean residual life function gives the expected remaining life at that age. Reliabilists and biometricians have found it useful to categorize failure distributions by the monotonicity properties of the mean residual life function. Hollander and Proschan (1975, Biometrika 62, 585-593) have derived tests o...

journal_title：Biometrics

authors： Chen YY,Hollander M,Langberg NA

更新日期：1983-03-01 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：: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：:Geographic disease surveillance methods identify regions that have higher disease rates than expected. These approaches are generally applied to incident or prevalent cases of disease. In some contexts, disease-related events rather than individuals are the appropriate units of analysis for geographic surveillance. We...

journal_title：Biometrics

authors： Rosychuk RJ,Huston C,Prasad NG

更新日期：2006-06-01 00:00:00

abstract：:A considerable body of literature has arisen over the past 15 years for analyzing univariate repeated measures data. However, it is rare in applied biomedical research for interest to be restricted to a single outcome measure. In this paper, we consider the case of bivariate repeated measures. We apply a generalized e...

journal_title：Biometrics

authors： Rochon J

更新日期：1996-06-01 00:00:00

abstract：:We consider Bayesian inference and model selection for prevalence estimation using a longitudinal two-phase design in which subjects initially receive a low-cost screening test followed by an expensive diagnostic test conducted on several occasions. The change in the subject's diagnostic probability over time is descr...

journal_title：Biometrics

authors： Erkanli A,Soyer R,Costello EJ

更新日期：1999-12-01 00:00:00

abstract：:Three properties of interest in bioavailability studies using compartmental models are the area under the concentration curve, the maximum concentration, and the time to maximum concentration. Methods are described for finding designs that minimize the variance of the estimates of these quantities in such a model. The...

journal_title：Biometrics

authors： Atkinson AC,Chaloner K,Herzberg AM,Juritz J

更新日期：1993-06-01 00:00:00

abstract：:A novel nonparametric regression model is developed for evaluating the covariate-specific accuracy of a continuous biological marker. Accurately screening diseased from nondiseased individuals and correctly diagnosing disease stage are critically important to health care on several fronts, including guiding recommenda...

journal_title：Biometrics

authors： Inácio de Carvalho V,de Carvalho M,Branscum AJ

更新日期：2017-12-01 00:00:00

abstract：:Given data from bilateral visual assessments on N subjects at k occasions, we consider inference for contralateral correlations (C) between fellow eyes and lateral correlations (L) among p different assessments of the same eye. Under permutation symmetric dependence structure between observations from fellow eyes and ...

journal_title：Biometrics

authors： Viana M,Olkin I

更新日期：2000-12-01 00:00:00

abstract：:In biomedical cohort studies for assessing the association between an outcome variable and a set of covariates, usually, some covariates can only be measured on a subgroup of study subjects. An important design question is-which subjects to select into the subgroup to increase statistical efficiency. When the outcome ...

journal_title：Biometrics

authors： Wang L,Williams ML,Chen Y,Chen J

更新日期：2020-03-01 00:00:00

abstract：:We present a class of simple designs that can be used in early dose-finding studies in HIV. Such designs, in contrast with Phase I designs in cancer, have a lot of the Phase II flavor about them. Information on efficacy is obtained during the trial and is as important as that relating to toxicity. The designs proposed...

journal_title：Biometrics

authors： O'Quigley J,Hughes MD,Fenton T

更新日期：2001-12-01 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：:The feasibility and cost-effectiveness of estimation of kappa using a case-control method of sampling, proposed by Jannarone, Macera, and Garrison (1987, Biometrics 43, 433-437), is provided support. However, in this article unrealistic assumptions in their presentation are identified and more general results for more...

journal_title：Biometrics

authors： Kraemer HC,Bloch DA

更新日期：1990-03-01 00:00:00

abstract：:Likelihood ratio tests for parameters estimated assuming normally distributed errors are examined under a variety of homoscedastic and heteroscedastic variance assumptions. It is assumed that gamma ij, the jth observation from the ith population, is distributed as N[mu(chi ij, beta i), (sigma i mu(chi ij, beta i)theta...

journal_title：Biometrics

authors： Kimura DK

更新日期：1990-09-01 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：:With the internet, a massive amount of information on species abundance can be collected by citizen science programs. However, these data are often difficult to use directly in statistical inference, as their collection is generally opportunistic, and the distribution of the sampling effort is often not known. In this...

journal_title：Biometrics

authors： Giraud C,Calenge C,Coron C,Julliard R

更新日期：2016-06-01 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：:Multiple outcomes are often used to properly characterize an effect of interest. This paper proposes a latent variable model for the situation where repeated measures over time are obtained on each outcome. These outcomes are assumed to measure an underlying quantity of main interest from different perspectives. We re...

journal_title：Biometrics

authors： Roy J,Lin X

更新日期：2000-12-01 00:00:00

abstract：:We describe a logistic-bivariate normal mixture model for a two-state Markov chain in which each individual makes transitions between states according to a subject-specific transition probability matrix. The use of the bivariate normal mixing distribution facilitates inferences regarding the correlation of the random ...

journal_title：Biometrics

authors： Cook RJ,Ng ET

更新日期：1997-03-01 00:00:00

abstract：:We develop a Bayesian nonparametric mixture modeling framework for quantal bioassay settings. The approach is built upon modeling dose-dependent response distributions. We adopt a structured nonparametric prior mixture model, which induces a monotonicity restriction for the dose-response curve. Particular emphasis is ...

journal_title：Biometrics

authors： Fronczyk K,Kottas A

更新日期：2014-03-01 00:00:00

abstract：:Asbestos exposure is a well-known risk factor for various lung diseases, and when they occur, workmen's compensation boards need to make decisions concerning the probability the cause is work related. In the absence of a definitive work history, measures of short and long asbestos fibers as well as counts of asbestos ...

journal_title：Biometrics

authors： Weichenthal S,Joseph L,Bélisle P,Dufresne A

更新日期：2010-06-01 00:00:00

abstract：:We consider inference for the reaction rates in discretely observed networks such as those found in models for systems biology, population ecology, and epidemics. Most such networks are neither slow enough nor small enough for inference via the true state-dependent Markov jump process to be feasible. Typically, infere...

journal_title：Biometrics

authors： Fearnhead P,Giagos V,Sherlock C

更新日期：2014-06-01 00:00:00