Abstract:
:An individual's health condition can affect the frequency and intensity of episodes that can occur repeatedly and that may be related to an event time of interest. For example, bleeding episodes during pregnancy may indicate problems predictive of preterm delivery. Motivated by this application, we propose a joint model for a multiple episode process and an event time. The frequency of occurrence and severity of the episodes are characterized by a latent variable model, which allows an individual's episode intensity to change dynamically over time. This latent episode intensity is then incorporated as a predictor in a discrete time model for the terminating event. Time-varying coefficients are used to distinguish among effects earlier versus later in gestation. Formulating the model within a Bayesian framework, prior distributions are chosen so that conditional posterior distributions are conjugate after data augmentation. Posterior computation proceeds via an efficient Gibbs sampling algorithm. The methods are illustrated using bleeding episode and gestational length data from a pregnancy study.
journal_name
Biometricsjournal_title
Biometricsauthors
Herring AH,Yang Jdoi
10.1111/j.1541-0420.2006.00720.xsubject
Has Abstractpub_date
2007-06-01 00:00:00pages
381-8issue
2eissn
0006-341Xissn
1541-0420pii
BIOM720journal_volume
63pub_type
杂志文章相关文献
BIOMETRICS文献大全abstract::Directed acyclic graphical (DAG) models are increasingly employed in the study of physical and biological systems to model direct influences between variables. Identifying the graph from data is a challenging endeavor, which can be more reasonably tackled if the variables are assumed to satisfy a given ordering; in th...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12018
更新日期:2013-06-01 00:00:00
abstract::The focus of this article is on the nature of the likelihood associated with N-mixture models for repeated count data. It is shown that the infinite sum embedded in the likelihood associated with the Poisson mixing distribution can be expressed in terms of a hypergeometric function and, thence, in closed form. The res...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12521
更新日期:2016-12-01 00:00:00
abstract::In studying rates of occurrence and progression of lesions (or tumors), it is typically not possible to obtain exact onset times for each lesion. Instead, data consist of the number of lesions that reach a detectable size between screening examinations, along with measures of the size/severity of individual lesions at...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341X.2004.00217.x
更新日期:2004-09-01 00:00:00
abstract::Given a large number of t-statistics, we consider the problem of approximating the distribution of noncentrality parameters (NCPs) by a continuous density. This problem is closely related to the control of false discovery rates (FDR) in massive hypothesis testing applications, e.g., microarray gene expression analysis...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2012.01764.x
更新日期:2012-12-01 00:00:00
abstract::In the field of cardio-thoracic surgery, valve function is monitored over time after surgery. The motivation for our research comes from a study which includes patients who received a human tissue valve in the aortic position. These patients are followed prospectively over time by standardized echocardiographic assess...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12814
更新日期:2018-06-01 00:00:00
abstract::Dose-response models are intensively used in herbicide bioassays. Despite recent advancements in the development of new herbicides, statistical analyses are commonly based on asymptotic approximations that are sometimes poor. This paper presents the use of recent results in higher order asymptotics for likelihood-base...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2000.01204.x
更新日期:2000-12-01 00:00:00
abstract::The simultaneous testing of multiple hypotheses is common to the analysis of high-dimensional data sets. The two-group model, first proposed by Efron, identifies significant comparisons by allocating observations to a mixture of an empirical null and an alternative distribution. In the Bayesian nonparametrics literatu...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13314
更新日期:2020-06-14 00:00:00
abstract::Interference occurs between individuals when the treatment (or exposure) of one individual affects the outcome of another individual. Previous work on causal inference methods in the presence of interference has focused on the setting where it is a priori assumed that there is "partial interference," in the sense that...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13125
更新日期:2020-03-01 00:00:00
abstract::The data set presented relates a binomial response to ordered levels of an explanatory variable, representing doses of a drug, with data collected at several centers. A study goal is to test independence of the response and the ordinal factor, assuming under the alternative only that the binomial parameter is a monoto...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1996-09-01 00:00:00
abstract::The Colton model for the choice between two medical treatments is studied, with the additional assumption that there is a time lag between the administration of the treatments and the availability of the responses. Two simple procedures are suggested for dealing with patients who arrive during the waiting period, caus...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1981-03-01 00:00:00
abstract::Spatial replication is a common theme in count surveys of animals. Such surveys often generate sparse count data from which it is difficult to estimate population size while formally accounting for detection probability. In this article, I describe a class of models (N-mixture models) which allow for estimation of pop...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341X.2004.00142.x
更新日期:2004-03-01 00:00:00
abstract::When testing the null hypothesis that treatment arm-specific survival-time distributions are equal, the log-rank test is asymptotically valid when the distribution of time to censoring is conditionally independent of randomized treatment group given survival time. We introduce a test of the null hypothesis for use whe...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/1541-0420.00059
更新日期:2003-09-01 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
pub_type: 杂志文章
doi:10.1111/1541-0420.00042
更新日期:2003-06-01 00:00:00
abstract::Brownie, Boos, and Hughes-Oliver (1990, Biometrics 46, 259-266) suggested a modification to the fixed-effects analysis of variance (ANOVA) F test for use in situations where treatments are likely to affect mean response while simultaneously increasing between-subject variability. These authors suggest that the modifie...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1993-09-01 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
pub_type: 杂志文章
doi:
更新日期:1982-09-01 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
pub_type: 杂志文章
doi:
更新日期:1983-06-01 00:00:00
abstract::Variable selection for clustering is an important and challenging problem in high-dimensional data analysis. Existing variable selection methods for model-based clustering select informative variables in a "one-in-all-out" manner; that is, a variable is selected if at least one pair of clusters is separable by this va...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2009.01341.x
更新日期:2010-09-01 00:00:00
abstract::Array-based CGH experiments are designed to detect genomic aberrations or regions of DNA copy-number variation that are associated with an outcome, typically a state of disease. Most of the existing statistical methods target on detecting DNA copy number variations in a single sample or array. We focus on the detectio...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12478
更新日期:2016-09-01 00:00:00
abstract::The standard approach to inference for random effects meta-analysis relies on approximating the null distribution of a test statistic by a standard normal distribution. This approximation is asymptotic on k, the number of studies, and can be substantially in error in medical meta-analyses, which often have only a few ...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.1999.00732.x
更新日期:1999-09-01 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
pub_type: 杂志文章
doi:10.1111/biom.12886
更新日期:2018-12-01 00:00:00
abstract::Pharmaceutical products are routinely monitored for their stability over time. Stability studies generally consist of a random sample of dosage units (e.g., tablets, capsules, vials) from a batch or several batches placed in a storage room and periodically assayed for their drug content. The degradation of the drug pr...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1991-09-01 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
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2011.01596.x
更新日期:2011-12-01 00:00:00
abstract::Training data in a supervised learning problem consist of the class label and its potential predictors for a set of observations. Constructing effective classifiers from training data is the goal of supervised learning. In biomedical sciences and other scientific applications, class labels may be subject to errors. We...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341X.2004.00156.x
更新日期:2004-03-01 00:00:00
abstract::The fitting of finite mixture models via the EM algorithm is considered for data which are available only in grouped form and which may also be truncated. A practical example is presented where a mixture of two doubly truncated log-normal distributions is adopted to model the distribution of the volume of red blood ce...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1988-06-01 00:00:00
abstract::This article presents a new approach for exploring the distribution of interindividual random effects in nonlinear mixed effect models. The approach introduces a spline function, which transforms an assumed normally distributed interindividual random effect to an arbitrary distribution approximating that of the data. ...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1995-12-01 00:00:00
abstract::In this article, we propose approximate sample size formulas for establishing equivalence or noninferiority of two treatments in match-pairs design. Using the ratio of two proportions as the equivalence measure, we derive sample size formulas based on a score statistic for two types of analyses: hypothesis testing and...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2002.00957.x
更新日期:2002-12-01 00:00:00
abstract::A mean residual life function is the average remaining life of a surviving subject, as it varies with time. The proportional mean residual life model was proposed by Oakes and Dasu (1990, Biometrika77, 409-410) in regression analysis to study its association with related covariates in absence of censoring. In this art...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341X.2005.030224.x
更新日期:2005-03-01 00:00:00
abstract::This paper presents the development, application and evaluation of a stochastic model of the frequency of occurrence of transient ischemic attacks (TIAs). TIAs occur during periods of abnormal arterial activity. The TIAs which occur during a single period of abnormal activity are called a cluster of TIAs. Thus, the nu...
journal_title:Biometrics
pub_type: 临床试验,杂志文章
doi:
更新日期:1980-03-01 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
pub_type: 杂志文章
doi:
更新日期:1989-03-01 00:00:00
abstract::The objective of this article is to develop a hypothesis-testing procedure to determine whether a common source outbreak has ended. We consider the case when neither the calendar date of exposure to the pathogen nor the exact incubation period distribution is known. The hypothesis-testing procedure is based on the spa...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2005.00421.x
更新日期:2006-03-01 00:00:00