Inferences on the association parameter in copula models for bivariate survival data.

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：:The clinical trial design in which the endpoint is measured both at baseline and at the end of the study is used in a variety of situations. For two-group designs, test such as the t test or analysis of covariance are commonly used to evaluate treatment efficacy. Often such pretest-posttest trials restrict participati...

journal_title：Biometrics

authors： Follmann DA

更新日期：1991-06-01 00:00:00

abstract：:In this paper, a Markov process is developed as a mathematical model to study the general problem of quality control monitoring. This approach was previously used by Arnold (1970) in development of sampling plans to study the water quality monitoring of streams. Arnold considered the expected sample size required for ...

journal_title：Biometrics

authors： Smeach SC,Jernigan RW

更新日期：1977-03-01 00:00:00

abstract：:For patients on dialysis, hospitalizations remain a major risk factor for mortality and morbidity. We use data from a large national database, United States Renal Data System, to model time-varying effects of hospitalization risk factors as functions of time since initiation of dialysis. To account for the three-level...

journal_title：Biometrics

authors： Li Y,Nguyen DV,Kürüm E,Rhee CM,Chen Y,Kalantar-Zadeh K,Şentürk D

更新日期：2020-09-01 00:00:00

abstract：:Tang, Gnecco, and Geller (1989, Biometrika 76, 577-583) proposed an approximate likelihood ratio (ALR) test of the null hypothesis that a normal mean vector equals a null vector against the alternative that all of its components are nonnegative with at least one strictly positive. This test is useful for comparing a t...

journal_title：Biometrics

authors： Tamhane AC,Logan BR

更新日期：2002-09-01 00:00:00

abstract：:Modeling of longitudinal data from agricultural experiments using growth curves helps understand conditions conducive or unconducive to crop growth. Recent advances in Geographical Information Systems (GIS) now allow geocoding of agricultural data that help understand spatial patterns. A particularly common problem is...

journal_title：Biometrics

authors： Banerjee S,Johnson GA

更新日期：2006-09-01 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：: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：: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：: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：:Vaccine-induced protection may not be homogeneous across individuals. It is possible that a vaccine gives complete protection for a portion of individuals, while the rest acquire only incomplete (leaky) protection of varying magnitude. If vaccine efficacy is estimated under wrong assumptions about such individual leve...

journal_title：Biometrics

authors： Mehtälä J,Dagan R,Auranen K

更新日期：2016-09-01 00:00:00

abstract：:Calibration, the statistical consistency of forecast distributions and the observations, is a central requirement for probabilistic predictions. Calibration of continuous forecasts is typically assessed using the probability integral transform histogram. In this article, we propose significance tests based on scoring ...

journal_title：Biometrics

authors： Held L,Rufibach K,Balabdaoui F

更新日期：2010-12-01 00:00:00

abstract：:It has become increasingly common in epidemiological studies to pool specimens across subjects to achieve accurate quantitation of biomarkers and certain environmental chemicals. In this article, we consider the problem of fitting a binary regression model when an important exposure is subject to pooling. We take a re...

journal_title：Biometrics

authors： Zhang Z,Albert PS

更新日期：2011-06-01 00:00:00

abstract：:The estimation of maternal genetic variances by a multivariate maximum likelihood method is discussed. As an illustration the method is applied to data on Tribolium using a model based on partitioning the maternal genetic effect into additive and dominance components. An alternative model due to Falconer (1965) is als...

journal_title：Biometrics

authors： Thompson R

更新日期：1976-12-01 00:00:00

abstract：:A class of adaptive weighted log-rank statistics is described where the vector of weights is chosen in a data-dependent way from a family of "smooth" weight vectors. A parametric family of weight vectors is identified which includes most shapes of weighting vectors that will be near optimal in many cancer prevention a...

journal_title：Biometrics

authors： Self SG

更新日期：1991-09-01 00:00:00

abstract：:Epidemiologic data for case-control studies are often summarized into K 2 x 2 tables. Given a fixed number of cases and controls, the degree of sparseness in the data depends on the number of strata, K. The effect of increasing stratification on size and power of seven tests of homogeneity of the odds ratio is studied...

journal_title：Biometrics

authors： Jones MP,O'Gorman TW,Lemke JH,Woolson RF

更新日期：1989-03-01 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：: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：: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：:Methods for modeling and mapping spatial variation in disease risk continue to motivate much research. In particular, spatial analyses provide a useful tool for exploring geographical heterogeneity in health outcomes, and consequently can yield clues as to disease etiology, direct public health management, and generat...

journal_title：Biometrics

authors： Costain DA

更新日期：2009-12-01 00:00:00

abstract：:Treatments are frequently evaluated in terms of their effect on patient survival. In settings where randomization of treatment is not feasible, observational data are employed, necessitating correction for covariate imbalances. Treatments are usually compared using a hazard ratio. Most existing methods which quantify ...

journal_title：Biometrics

authors： Gong Q,Schaubel DE

更新日期：2017-03-01 00:00:00

abstract：:A comparison was made of various tests for Hardy-Weinberg equilibrium, with emphasis on methods for multiple alleles. For an overall test of deviations from equilibrium, the classical chi-square goodness-of-fit test generally performs well, with continuity corrections needed for extreme gene frequencies or extreme dep...

journal_title：Biometrics

authors： Hernández JL,Weir BS

更新日期：1989-03-01 00:00:00

abstract：:Left truncation commonly occurs in many areas, and many methods have been proposed in the literature for the analysis of various types of left-truncated failure time data. For the situation, a common approach is to conduct the analysis conditional on truncation times, and the method is relatively simple but may not be...

journal_title：Biometrics

authors： Wang P,Li D,Sun J

更新日期：2020-10-15 00:00:00

abstract：:Spatial weed count data are modeled and predicted using a generalized linear mixed model combined with a Bayesian approach and Markov chain Monte Carlo. Informative priors for a data set with sparse sampling are elicited using a previously collected data set with extensive sampling. Furthermore, we demonstrate that so...

journal_title：Biometrics

authors： Christensen OF,Waagepetersen R

更新日期：2002-06-01 00:00:00

abstract：:Recent advances in human genetics have led to a renewed interest in statistical methods for the detection of linkage from family data--for example, between marker loci and disease traits. Statistical analysis of linkage between two loci is carried out almost exclusively by means of the lod (log-odds) score test, equiv...

journal_title：Biometrics

authors： Shoukri MM,Lathrop GM

更新日期：1993-03-01 00:00:00

abstract：:In Western countries where food supply is satisfactory, consumers organize their diets around a large combination of foods. It is the purpose of this article to examine how recent nonnegative matrix factorization (NMF) techniques can be applied to food consumption data to understand these combinations. Such data are n...

journal_title：Biometrics

authors： Zetlaoui M,Feinberg M,Verger P,Clémençon S

更新日期：2011-12-01 00:00:00

abstract：:Zhao and Tsiatis (1997) consider the problem of estimation of the distribution of the quality-adjusted lifetime when the chronological survival time is subject to right censoring. The quality-adjusted lifetime is typically defined as a weighted sum of the times spent in certain states up until death or some other fail...

journal_title：Biometrics

authors： van der Laan MJ,Hubbard A

更新日期：1999-06-01 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：: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：: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