Improved doubly robust estimation when data are monotonely coarsened, with application to longitudinal studies with dropout.

abstract：:Despite major methodological developments, Bayesian inference in Gaussian graphical models remains challenging in high dimension due to the tremendous size of the model space. This article proposes a method to infer the marginal and conditional independence structures between variables by multiple testing, which bypas...

journal_title：Biometrics

authors： Leday GGR,Richardson S

更新日期：2019-12-01 00:00:00

abstract：:This paper studies randomization model methods for analyzing data from a multicenter study comparing the effectiveness of two treatments. The Mantel-Haenszel mean score statistic, which can be used for continuous or ordered categorical response variables, is shown to be a useful nonparametric alternative to standard l...

journal_title：Biometrics

authors： Davis CS,Chung Y

更新日期：1995-09-01 00:00:00

abstract：:As ultra high-dimensional longitudinal data are becoming ever more apparent in fields such as public health and bioinformatics, developing flexible methods with a sparse model is of high interest. In this setting, the dimension of the covariates can potentially grow exponentially as ...

journal_title：Biometrics

authors： Green B,Lian H,Yu Y,Zu T

更新日期：2020-08-04 00:00:00

abstract：:We propose a sequential approach for constructing multiple-objective locally optimal designs for nonlinear models. The technique used here is a general one and we demonstrate the added benefits of using a multiple-objective design over a single-objective design with examples from biomedical studies. ...

journal_title：Biometrics

authors： Huang YC,Wong WK

更新日期：1998-12-01 00:00:00

abstract：:Spatial cluster detection is an important methodology for identifying regions with excessive numbers of adverse health events without making strong model assumptions on the underlying spatial dependence structure. Previous work has focused on point or individual-level outcome data and few advances have been made when ...

journal_title：Biometrics

authors： Cook AJ,Li Y,Arterburn D,Tiwari RC

更新日期：2010-09-01 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

abstract：:Whenever inference for variance components is required, the choice between one-sided and two-sided tests is crucial. This choice is usually driven by whether or not negative variance components are permitted. For two-sided tests, classical inferential procedures can be followed, based on likelihood ratios, score stati...

journal_title：Biometrics

authors： Verbeke G,Molenberghs G

更新日期：2003-06-01 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：:Complex issues arise when investigating the association between longitudinal immunologic measures and time to an event, such as time to relapse, in cancer vaccine trials. Unlike many clinical trials, we may encounter patients who are cured and no longer susceptible to the time-to-event endpoint. If there are cured pat...

journal_title：Biometrics

authors： Brown ER,Ibrahim JG

更新日期：2003-09-01 00:00:00

abstract：:We derive semiparametric methods for estimating and testing treatment effects when censored recurrent event data are available over multiple periods. These methods are based on estimating functions motivated by a working "mixed-Poisson" assumption under which conditioning can eliminate subject-specific random effects....

journal_title：Biometrics

authors： Cook RJ,Wei W,Yi GY

更新日期：2005-09-01 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：:Conditional likelihood based on counting processes are combined with a Horvitz-Thompson estimator to yield a population size estimator that is more efficient than the existing ones. Random removals are allowed in the recapturing process. Simulation studies are shown to assess the performance of the proposed estimators...

journal_title：Biometrics

authors： Yip PS,Wang Y

更新日期：2002-03-01 00:00:00

abstract：:There is a simple robust variance estimator for cluster-correlated data. While this estimator is well known, it is poorly documented, and its wide range of applicability is often not understood. The estimator is widely used in sample survey research, but the results in the sample survey literature are not easily appli...

journal_title：Biometrics

authors： Williams RL

更新日期：2000-06-01 00:00:00

abstract：:Prentice and Sheppard (1995, Biometrika 82, 113-125) proposed a method for estimating relative risks associated with poorly measured exposures using disease rates from multiple populations and exposure and confounding factor data from sample surveys of persons in each population. The method involved an assumption of i...

journal_title：Biometrics

authors： Anderson AB,Prentice RL

更新日期：1998-12-01 00:00:00

abstract：:In this article, we present an estimation approach for solving nonlinear constrained generalized estimating equations that can be implemented using object-oriented software for nonlinear programming, such as nlminb in Splus or fmincon and lsqnonlin in Matlab. We show how standard estimating equation theory includes th...

journal_title：Biometrics

authors： Contreras M,Ryan LM

更新日期：2000-12-01 00:00:00

abstract：:The approach to early termination for efficacy in a trial where events occur over time but the primary question of interest relates to a long-term binary endpoint is not straightforward. This article considers comparison of treatment groups with Kaplan-Meier (KM) proportions evaluated at increasing times from randomiz...

journal_title：Biometrics

authors： Brittain E,Follmann D,Yang S

更新日期：2008-03-01 00:00:00

abstract：:Large amounts of longitudinal health records are now available for dynamic monitoring of the underlying processes governing the observations. However, the health status progression across time is not typically observed directly: records are observed only when a subject interacts with the system, yielding irregular and...

journal_title：Biometrics

authors： Luo Y,Stephens DA,Verma A,Buckeridge DL

更新日期：2020-03-11 00:00:00

abstract：:This paper establishes a framework for understanding the complex relationships between HIV-1 genotypic markers of resistance to antiretroviral drugs and clinical measures of disease progression. A new classification scheme based on the probabilities of how new patients will respond to antiretroviral therapy given the ...

journal_title：Biometrics

authors： Foulkes AS,De GV

更新日期：2002-03-01 00:00:00

abstract：:In clinical trials and other investigations of survival time, information is often available on a time-dependent event other than survival. An example of such an auxiliary event in cancer studies is objective progression of disease. While some patients expire without experiencing objective disease progression, others ...

journal_title：Biometrics

authors： Lagakos SW

更新日期：1976-09-01 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：:When a true survival endpoint cannot be assessed for some subjects, an alternative endpoint that measures the true endpoint with error may be collected, which often occurs when obtaining the true endpoint is too invasive or costly. We develop an estimated likelihood function for the situation where we have both uncert...

journal_title：Biometrics

authors： Zee J,Xie SX

更新日期：2015-09-01 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：: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：: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：:Many techniques of functional data analysis require choosing a measure of distance between functions, with the most common choice being L2 distance. In this article we show that using a weighted L2 distance, with a judiciously chosen weight function, can improve the performance of various statistical methods for funct...

journal_title：Biometrics

authors： Chen H,Reiss PT,Tarpey T

更新日期：2014-09-01 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：:In epidemiologic studies, subjects are often misclassified as to their level of exposure. Ignoring this misclassification error in the analysis introduces bias in the estimates of certain parameters and invalidates many hypothesis tests. For situations in which there is misclassification of exposure in a follow-up stu...

journal_title：Biometrics

authors： Reade-Christopher SJ,Kupper LL

更新日期：1991-06-01 00:00:00

abstract：:We describe a simple, computationally efficient, permutation-based procedure for selecting the penalty parameter in LASSO-penalized regression. The procedure, permutation selection, is intended for applications where variable selection is the primary focus, and can be applied in a variety of structural settings, inclu...

journal_title：Biometrics

authors： Sabourin JA,Valdar W,Nobel AB

更新日期：2015-12-01 00:00:00

abstract：:Mixed longitudinal growth data consists of several observations on a characteristic over a limited age range for each individual in a study. This data is then combined to model growth over the total age range of all individuals in the study. The limited data collected on each individual precludes a subject-specific ap...

journal_title：Biometrics

authors： Huggins RM,Loesch DZ

更新日期：1998-06-01 00:00:00

abstract：:When comparing follow-up measurements from two independent populations, missing records may arise due to censoring by events whose occurrence is associated with baseline covariates. In these situations, inferences based only on the completely followed observations may be biased if the follow-up measurements and the co...

journal_title：Biometrics

authors： Cheung YK

更新日期：2005-06-01 00:00:00