Testing equality of survival functions based on both paired and unpaired censored data.

abstract：:Prognostic models in survival analysis typically aim to describe the association between patient covariates and future outcomes. More recently, efforts have been made to include covariate information that is updated over time. However, there exists as yet no standard approach to assess the predictive accuracy of such ...

journal_title：Biometrics

authors： Schoop R,Graf E,Schumacher M

更新日期：2008-06-01 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：:Brain connectivity analysis is now at the foreground of neuroscience research. A connectivity network is characterized by a graph, where nodes represent neural elements such as neurons and brain regions, and links represent statistical dependence that is often encoded in terms of partial correlation. Such a graph is i...

journal_title：Biometrics

authors： Xia Y,Li L

更新日期：2017-09-01 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：:We describe an adaptive Bayesian design for a clinical trial of an experimental treatment for patients with hematologic malignancies who initially received an allogeneic bone marrow transplant but subsequently suffered a disease recurrence. Treatment consists of up to two courses of targeted immunotherapy followed by ...

journal_title：Biometrics

authors： Thall PF,Inoue LY,Martin TG

更新日期：2002-09-01 00:00:00

abstract：:Several models for the course of microbial infections during the incubation period are examined. Each model fits sore throat incubation data very well. Together with the lack of precision of the resulting parameter estimates, this suggests that incubation data alone are insufficient for elucidating the finer details o...

journal_title：Biometrics

authors： Morgan BJ,Watts SA

更新日期：1980-06-01 00:00:00

abstract：:In this article, we develop new methods for estimating average treatment effects in observational studies, in settings with more than two treatment levels, assuming unconfoundedness given pretreatment variables. We emphasize propensity score subclassification and matching methods which have been among the most popular...

journal_title：Biometrics

authors： Yang S,Imbens GW,Cui Z,Faries DE,Kadziola Z

更新日期：2016-12-01 00:00:00

abstract：:We develop a parameterization of the beta-binomial mixture that provides sensible inferences about the size of a closed population when probabilities of capture or detection vary among individuals. Three classes of mixture models (beta-binomial, logistic-normal, and latent-class) are fitted to recaptures of snowshoe h...

journal_title：Biometrics

authors： Dorazio RM,Royle JA

更新日期：2003-06-01 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：:Some failure time data come from a population that consists of some subjects who are susceptible to and others who are nonsusceptible to the event of interest. The data typically have heavy censoring at the end of the follow-up period, and a standard survival analysis would not always be appropriate. In such situation...

journal_title：Biometrics

authors： Sy JP,Taylor JM

更新日期：2000-03-01 00:00:00

abstract：:A likelihood ratio statistic is proposed for testing goodness of fit with grouped data which are subject to random right censoring. It is shown that, under appropriate conditions, this statistic has an asymptotic chi-square distribution which is non-central under contiguous alternatives. A formula is given for the non...

journal_title：Biometrics

authors： Turnbull BW,Weiss L

更新日期：1978-09-01 00:00:00

abstract：:In multivariate survival analysis, investigators are often interested in testing for heterogeneity among clusters, both overall and within specific classes. We represent different hypotheses about the heterogeneity structure using a sequence of gamma frailty models, ranging from a null model with no random effects to ...

journal_title：Biometrics

authors： Dunson DB,Chen Z

更新日期：2004-06-01 00:00:00

abstract：:We extend the linear random-effects growth curve model (REGCM) (Laird and Ware, 1982, Biometrics 38, 963-974) to study the effects of population covariates on one or more characteristics of the growth curve when the characteristics are expressed as linear combinations of the growth curve parameters. This definition in...

journal_title：Biometrics

authors： Stukel TA,Demidenko E

更新日期：1997-06-01 00:00:00

abstract：:This note discusses the use of capture-mark-recapture methods and log-linear, linear, product models for incomplete tables (Espeland, 1986, Communications in Statistics--Simulation and Computing 15, 405-424) to estimate completeness of reporting in a disease registry and to estimate incompleteness-adjusted incidence r...

journal_title：Biometrics

authors： Hilsenbeck SG,Kurucz C,Duncan RC

更新日期：1992-12-01 00:00:00

abstract：:Adaptive line transect sampling offers the potential of improved population density estimation efficiency over conventional line transect sampling when populations are spatially clustered. In adaptive sampling, survey effort is increased when areas of high animal density are located, thereby increasing the number of o...

journal_title：Biometrics

authors： Pollard JH,Palka D,Buckland ST

更新日期：2002-12-01 00:00:00

abstract：:A wide variety of similarity indices for comparing two assemblages based on species incidence (i.e., presence/absence) data have been proposed in the literature. These indices are generally based on three simple incidence counts: the number of species shared by two assemblages and the number of species unique to each ...

journal_title：Biometrics

authors： Chao A,Chazdon RL,Colwell RK,Shen TJ

更新日期：2006-06-01 00:00:00

abstract：:For the case of repeated measures on Y with mean values linear in a concomitant variable Z in [a, b], a straight-line confidence band over [a, b] is given with width linear in Z. Graphical presentation of such line-segment confidence bands can help emphasize that appropriate inferences are limited to the range of the ...

journal_title：Biometrics

authors： Stewart PW

更新日期：1987-09-01 00:00:00

abstract：:Advances in sequencing technologies and bioinformatics tools have vastly improved our ability to collect and analyze data from complex microbial communities. A major goal of microbiome studies is to correlate the overall microbiome composition with clinical or environmental variables. La Rosa et al. recently proposed ...

journal_title：Biometrics

authors： Song Y,Zhao H,Wang T

更新日期：2020-06-01 00:00:00

abstract：:Assuming a model of proportional failure rates, Cox (1972) presents a systematic study of the use of covariates in the analysis of life time. The treatment of tied observations is a particularly troublesome point in both theory and application. It appears that grouping rather than discrete time is the right way to han...

journal_title：Biometrics

authors： Thompson WA Jr

更新日期：1977-09-01 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：:We consider a two-sample problem where data come from symmetric distributions. Usual two-sample data with only magnitudes recorded, arising from case-control studies or logistic discriminant analyses, may constitute a symmetric two-sample problem. We propose a semiparametric model such that, in addition to symmetry, t...

journal_title：Biometrics

authors： Li M,Diao G,Qin J

更新日期：2020-12-01 00:00:00

abstract：:This article introduces an original methodology based on empirical likelihood, which aims at combining different food contamination and consumption surveys to provide risk managers with a risk measure, taking into account all the available information. This risk index is defined as the probability that exposure to a c...

journal_title：Biometrics

authors： Crépet A,Harari-Kermadec H,Tressou J

更新日期：2009-03-01 00:00:00

abstract：:The spending function approach proposed by Lan and DeMets (1983, Biometrika 70, 659-663) for sequential monitoring of clinical trials is applied to situations where comparison of changes in a continuous response variable between two groups is the primary concern. Death, loss to follow-up, and missed visits could cause...

journal_title：Biometrics

authors： Wu MC,Lan KK

更新日期：1992-09-01 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 method purporting to provide optimal allocations in bioequivalence studies fails to do so on both statistical and practical grounds. Reasons as to why this is so are given. ...

journal_title：Biometrics

authors： Senn S,Grieve AP

更新日期：1999-12-01 00:00:00

abstract：:In the evaluation of diagnostic accuracy of tests, a gold standard on the disease status is required. However, in many complex diseases, it is impossible or unethical to obtain such a gold standard. If an imperfect standard is used, the estimated accuracy of the tests would be biased. This type of bias is called imper...

journal_title：Biometrics

authors： Zhou XH,Castelluccio P,Zhou C

更新日期：2005-06-01 00:00:00

abstract：:The basic problem under consideration is the comparison of treatments with respect to a response Y when a covariable X is taken into account. Various methods involving matching may be regarded as compromises between the standard analysis of covariance and the standard analysis of independent matched pairs. First, ther...

journal_title：Biometrics

authors： Quade D

更新日期：1982-09-01 00:00:00

abstract：:In clinical studies, longitudinal biomarkers are often used to monitor disease progression and failure time. Joint modeling of longitudinal and survival data has certain advantages and has emerged as an effective way to mutually enhance information. Typically, a parametric longitudinal model is assumed to facilitate t...

journal_title：Biometrics

authors： Ding J,Wang JL

更新日期：2008-06-01 00:00:00

abstract：:For patients with chronic myelogenous leukemia (CML), the effect of elevated blood levels of adenosine deaminase (ADA) is studied as a marker for transitions from stable disease to blast crisis and then to death. Data in the form of snapshots over time, with day, state of disease, and ADA level, are analyzed for 55 pa...

journal_title：Biometrics

authors： Klein JP,Klotz JH,Grever MR

更新日期：1984-12-01 00:00:00

abstract：:In practice, when analyzing data from a capture-recapture experiment it is tempting to apply modern advanced statistical methods to the observed capture histories. However, unless the analysis takes into account that the data have only been collected from individuals who have been captured at least once, the results m...

journal_title：Biometrics

authors： Stoklosa J,Hwang WH,Wu SH,Huggins R

更新日期：2011-12-01 00:00:00