A note on the conditional approach to interval estimation in the calibration problem.

abstract：:We propose a likelihood-based test for comparing the means of two or more log-normal distributions, with possibly unequal variances. A modification to the likelihood ratio test is needed when sample sizes are small. The performance of the proposed procedures is compared with the F-ratio test using Monte Carlo simulati...

journal_title：Biometrics

authors： Gill PS

更新日期：2004-06-01 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：:The Wilcoxon rank sum test is widely used for two-group comparisons for nonnormal data. An assumption of this test is independence of sampling units both between and within groups. In ophthalmology, data are often collected on two eyes of an individual, which are highly correlated. In ophthalmological clinical trials,...

journal_title：Biometrics

authors： Rosner B,Glynn RJ,Lee ML

更新日期：2006-12-01 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：:A ranked set sampling procedure with unequal samples (RSSU) is proposed and used to estimate the population mean. This estimator is then compared with the estimators based on the ranked set sampling (RSS) and median ranked set sampling (MRSS) procedures. It is shown that the relative precisions of the estimator based ...

journal_title：Biometrics

authors： Bhoj DS

更新日期：2001-09-01 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：:With advancements in technology, the collection of multiple types of measurements on a common set of subjects is becoming routine in science. Some notable examples include multimodal neuroimaging studies for the simultaneous investigation of brain structure and function and multi-omics studies for combining genetic an...

journal_title：Biometrics

authors： Zhao Y,Li L,Caffo BS

更新日期：2020-08-13 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：: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：:Variable selection for recovering sparsity in nonadditive and nonparametric models with high-dimensional variables has been challenging. This problem becomes even more difficult due to complications in modeling unknown interaction terms among high-dimensional variables. There is currently no variable selection method ...

journal_title：Biometrics

authors： Fang Z,Kim I,Schaumont P

更新日期：2016-12-01 00:00:00

abstract：:The situation considered is the prediction of a future observation from a simple exponential survival distribution in a hierarchical Bayes context. It is shown that when the hyperparameters need to be estimated from the data, a sample reuse approach is superior to maximum likelihood and method of moments estimation pr...

journal_title：Biometrics

authors： Geisser S

更新日期：1990-03-01 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：:I discuss diagnostic methods for discriminant analysis. The equivalence with linear regression is noted and regression diagnostics are considered. The leverage is a function of the linear discriminant function and the Mahalanobis distance of the observation from the group mean. The distribution of this distance is app...

journal_title：Biometrics

authors： Lachenbruch PA

更新日期：1997-12-01 00:00:00

abstract：:A stochastic model is presented for the analysis of incomplete repeated-measures experiments. The general linear model is used to relate the response measures to other variables which are thought to account for inherent variation; an autoregressive moving average (ARMA) time series representation is used to model dist...

journal_title：Biometrics

authors： Rochon J,Helms RW

更新日期：1989-03-01 00:00:00

abstract：:Often with data from immunoassays, the concentration-response relationship is nonlinear and intra-assay response variance is heterogeneous. Estimation of the standard curve is usually based on a nonlinear heteroscedastic regression model for concentration-response, where variance is modeled as a function of mean respo...

journal_title：Biometrics

authors： Belanger BA,Davidian M,Giltinan DM

更新日期：1996-03-01 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：:We consider modeling correlated survival data when cluster sizes may be informative to the outcome of interest based on a within-cluster resampling (WCR) approach and a weighted score function (WSF) method. We derive the large sample properties for the WCR estimators under the Cox proportional hazards model. We establ...

journal_title：Biometrics

authors： Cong XJ,Yin G,Shen Y

更新日期：2007-09-01 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：:Objective measures of oxygen consumption and carbon dioxide production by mammals are used to predict their energy expenditure. Since energy expenditure is not directly observable, it can be viewed as a latent construct with multiple physical indirect measures such as respiratory quotient, volumetric oxygen consumptio...

journal_title：Biometrics

authors： Tekwe CD,Zoh RS,Bazer FW,Wu G,Carroll RJ

更新日期：2018-03-01 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：:We introduce two test procedures for comparing two survival distributions on the basis of randomly right-censored data consisting of both paired and unpaired observations. Our procedures are based on generalizations of a pooled rank test statistic previously proposed for uncensored data. One generalization adapts the ...

journal_title：Biometrics

authors： Dallas MJ,Rao PV

更新日期：2000-03-01 00:00:00

abstract：:A model specified in terms of linear models for marginal logits and linear models for log-odds ratios is proposed for the analysis of two-period binary cross-over experiments. Hypothesis testing and parameter estimation are facilitated by standard likelihood methodology. Two examples are used to illustrate how the mod...

journal_title：Biometrics

authors： Becker MP,Balagtas CC

更新日期：1993-12-01 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：:An adjusted rank correlation test is proposed as a technique for identifying publication bias in a meta-analysis, and its operating characteristics are evaluated via simulations. The test statistic is a direct statistical analogue of the popular "funnel-graph." The number of component studies in the meta-analysis, the...

journal_title：Biometrics

authors： Begg CB,Mazumdar M

更新日期：1994-12-01 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：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 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：:We consider a semiparametric inference procedure for data from epidemiologic studies conducted with a two-component sampling scheme where both a simple random sample and multiple outcome- or outcome-/auxiliary-dependent samples are observed. This sampling scheme allows the investigators to oversample certain subpopula...

journal_title：Biometrics

authors： Wang X,Zhou H

更新日期：2006-12-01 00:00:00

abstract：:We explore the use of a posterior predictive loss criterion for model selection for incomplete longitudinal data. We begin by identifying a property that most model selection criteria for incomplete data should consider. We then show that a straightforward extension of the Gelfand and Ghosh (1998, Biometrika, 85, 1-11...

journal_title：Biometrics

authors： Daniels MJ,Chatterjee AS,Wang C

更新日期：2012-12-01 00:00:00

abstract：:Eguchi and Matsuura (1990, Biometrics 46, 415-426) noted that the generalized Stevens test statistic for the Hardy-Weinberg law for human leukocyte antigen (HLA) data yields an excessively large value when no double blanks are observed. In this paper, we investigated this aberrant case. The inflated value of the test ...

journal_title：Biometrics

authors： Nam J

更新日期：1995-03-01 00:00:00