A likelihood ratio statistic for testing goodness of fit with randomly censored data.

abstract：:Linear multivariate theory is applied to the problem of combining several multivariate bioassays. Results are an asymptotic test of the hypothesis of a common log relative potency; the maximum likelihood estimator of the common log relative potency; and an exact and asymptotic confidence interval estimator for log rel...

journal_title：Biometrics

authors： Meisner M,Kushner HB,Laska EM

更新日期：1986-06-01 00:00:00

abstract：:With increasing frequency, epidemiologic studies are addressing hypotheses regarding gene-environment interaction. In many well-studied candidate genes and for standard dietary and behavioral epidemiologic exposures, there is often substantial prior information available that may be used to analyze current data as wel...

journal_title：Biometrics

authors： Mukherjee B,Ahn J,Gruber SB,Ghosh M,Chatterjee N

更新日期：2010-09-01 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：:R. A. Fisher is widely respected for his contributions to both statistics and genetics. For instance, his 1930 text on The Genetical Theory of Natural Selection remains a watershed contribution in that area. Fisher's subsequent research led him to study the work of (Johann) Gregor Mendel, the 19th century monk who fir...

journal_title：Biometrics

authors： Piegorsch WW

更新日期：1990-12-01 00:00:00

abstract：:We briefly review the major contribution of biometrics to genetics over the last century (population genetic models, familial correlations, segregation analysis, and gene mapping) and current areas of active research and then speculate about what problems will be tackled in the next century. ...

journal_title：Biometrics

authors： Elston RC,Thompson EA

更新日期：2000-09-01 00:00:00

abstract：:In large cohort studies, it often happens that some covariates are expensive to measure and hence only measured on a validation set. On the other hand, relatively cheap but error-prone measurements of the covariates are available for all subjects. Regression calibration (RC) estimation method (Prentice, 1982, Biometri...

journal_title：Biometrics

authors： Yu M,Nan B

更新日期：2010-06-01 00:00:00

abstract：:We present a method for individual and integrative analysis of high dimension, low sample size data that capitalizes on the recurring theme in multivariate analysis of projecting higher dimensional data onto a few meaningful directions that are solutions to a generalized eigenvalue problem. We propose a general framew...

journal_title：Biometrics

authors： Safo SE,Ahn J,Jeon Y,Jung S

更新日期：2018-12-01 00:00:00

abstract：:Quantitative traits analyzed in Genome-Wide Association Studies (GWAS) are often nonnormally distributed. For such traits, association tests based on standard linear regression are subject to reduced power and inflated type I error in finite samples. Applying the rank-based inverse normal transformation (INT) to nonno...

journal_title：Biometrics

authors： McCaw ZR,Lane JM,Saxena R,Redline S,Lin X

更新日期：2020-12-01 00:00:00

abstract：:Some new scale estimators for the censored two-sample accelerated life model are introduced. They are zeros of some integrated weighted difference between the two cumulative hazard estimators. These estimators are asymptotically normal. The weight is chosen to result in estimators whose asymptotic variances do not inv...

journal_title：Biometrics

authors： Yang S

更新日期：1998-09-01 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：:A Bayesian hierarchical generalized linear model is used to estimate hunting success rates at the subarea level for postseason harvest surveys. The model includes fixed week effects, random geographic effects, and spatial correlations between neighboring subareas. The computation is done by Gibbs sampling and adaptive...

journal_title：Biometrics

authors： He Z,Sun D

更新日期：2000-06-01 00:00:00

abstract：:This article considers sieve estimation in the Cox model with an unknown regression structure based on right-censored data. We propose a semiparametric pursuit method to simultaneously identify and estimate linear and nonparametric covariate effects based on B-spline expansions through a penalized group selection meth...

journal_title：Biometrics

authors： Cao Y,Huang J,Liu Y,Zhao X

更新日期：2016-12-01 00:00:00

abstract：:In studies of serial cancer markers or disease states and their relation to survival, data on the marker or state are usually obtained at infrequent time points during follow-up. A Markov model is developed to assess the dependence of risk of death on marker level or disease state and inferences within this model are ...

journal_title：Biometrics

authors： Kay R

更新日期：1986-12-01 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：:Tsiatis, Rosner, and Mehta (1984, Biometrics 40, 797-803) proposed a procedure for constructing confidence intervals following group sequential tests of a normal mean. This method is first extended for group sequential tests for which the sample sizes between interim analyses are not identical or the times are not equ...

journal_title：Biometrics

authors： Kim K,DeMets DL

更新日期：1987-12-01 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：: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：:Estimation of treatment effects in randomized studies is often hampered by possible selection bias induced by conditioning on or adjusting for a variable measured post-randomization. One approach to obviate such selection bias is to consider inference about treatment effects within principal strata, that is, principal...

journal_title：Biometrics

authors： Long DM,Hudgens MG

更新日期：2013-12-01 00:00:00

abstract：:Computer simulation has been used to compare four methods for calculating confidence intervals for simple rate ratios estimated from cohort studies. The method proposed by Cornfield (1956. In Proceedings of the Third Berkeley Symposium on Mathematical Statistics and Probability. Vol. IV, 135-148) for interval estimati...

journal_title：Biometrics

authors： Howe GR

更新日期：1983-06-01 00:00:00

abstract：:We estimate how the effect of antiretroviral treatment depends on the time from HIV-infection to initiation of treatment, using observational data. A major challenge in making inferences from such observational data arises from biases associated with the nonrandom assignment of treatment, for example bias induced by d...

journal_title：Biometrics

authors： Lok JJ,DeGruttola V

更新日期：2012-09-01 00:00:00

abstract：:A method is developed for obtaining tree-structured relative risk estimates for censored survival data. The first step of a full likelihood estimation procedure is used in a recursive partitioning algorithm that adopts most aspects of the widely used Classification and Regression Tree (CART) algorithm of Breiman et al...

journal_title：Biometrics

authors： LeBlanc M,Crowley J

更新日期：1992-06-01 00:00:00

abstract：:This paper presents a comparison of three methods of parameter estimation in analysis of linkage between a quantitative trait locus (QTL) and a marker locus: maximum likelihood, mean square for trait cumulative distribution function, and method of moments, employing simulated backcross data. The sensitivity of estimat...

journal_title：Biometrics

authors： Korol AB,Ronin YI,Kirzhner VM

更新日期：1996-06-01 00:00:00

abstract：:In longitudinal observational studies, repeated measures are often taken at informative observation times. Also, there may exist a dependent terminal event such as death that stops the follow-up. For example, patients in poorer health are more likely to seek medical treatment and their medical cost for each visit tend...

journal_title：Biometrics

authors： Liu L,Huang X,O'Quigley J

更新日期：2008-09-01 00:00:00

abstract：:Epidemiolgic studies have strongly suggested that a vast majority (80-90%) of cancers are caused by radiation, chemical and biologic agents; the remainder result from endogenous or genetic factors. Biologically, cancer is most probably the end result of a complex multistage process and therefore may be due to a sequen...

journal_title：Biometrics

authors： Lilienfeld AM

更新日期：1982-03-01 00:00:00

abstract：:The use of summary rates of reporting health data is discussed. Directly and indirectly adjusted rates are compared under two models of no interaction. A method of analysis is described whereby a model is first fitted to data in order to investigate assumptions, and subsequently the smoothed rates based on the model a...

journal_title：Biometrics

authors： Freeman DH Jr,Holford TR

更新日期：1980-06-01 00:00:00

abstract：:This paper discusses interval estimation of the risk ratio (RR) between a secondary infection, given a primary infection, and the primary infection. Three asymptotic closed-form interval estimators are developed using Wald's test statistic, the logarithmic transformation, and Fieller's theorem. The performance of thes...

journal_title：Biometrics

authors： Lui KJ

更新日期：1998-06-01 00:00:00

abstract：:In binomial group testing, unlike one-at-a-time testing, the test unit consists of a group of individuals, and each group is declared to be defective or nondefective. A defective group is one that is presumed to include one or more defective (e.g., infected, positive) individuals and a nondefective group to contain on...

journal_title：Biometrics

authors： Hung M,Swallow WH

更新日期：1999-03-01 00:00:00

abstract：:Understanding HIV incidence, the rate at which new infections occur in populations, is critical for tracking and surveillance of the epidemic. In this article, we derive methods for determining sample sizes for cross-sectional surveys to estimate incidence with sufficient precision. We further show how to specify samp...

journal_title：Biometrics

authors： Konikoff J,Brookmeyer R

更新日期：2015-12-01 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：: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