Assessing the causal effect of organ transplantation on the distribution of residual lifetime.

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：:Modeling of longitudinal data from agricultural experiments using growth curves helps understand conditions conducive or unconducive to crop growth. Recent advances in Geographical Information Systems (GIS) now allow geocoding of agricultural data that help understand spatial patterns. A particularly common problem is...

journal_title：Biometrics

authors： Banerjee S,Johnson GA

更新日期：2006-09-01 00:00:00

abstract：:Highly active antiretroviral therapy (HAART) has proved efficient in increasing CD4 counts in many randomized clinical trials. Because randomized trials have some limitations (e.g., short duration, highly selected subjects), it is interesting to assess the effect of treatments using observational studies. This is chal...

journal_title：Biometrics

authors： Prague M,Commenges D,Gran JM,Ledergerber B,Young J,Furrer H,Thiébaut R

更新日期：2017-03-01 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：: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：: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：: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：: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：:Diggle and Kenward (1994, Applied Statistics 43, 49-93) proposed a selection model for continuous longitudinal data subject to nonrandom dropout. It has provoked a large debate about the role for such models. The original enthusiasm was followed by skepticism about the strong but untestable assumptions on which this t...

journal_title：Biometrics

authors： Verbeke G,Molenberghs G,Thijs H,Lesaffre E,Kenward MG

更新日期：2001-03-01 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：:We consider methods for estimating the treatment effect and/or the covariate by treatment interaction effect in a randomized clinical trial under noncompliance with time-to-event outcome. As in Cuzick et al. (2007), assuming that the patient population consists of three (possibly latent) subgroups based on treatment p...

journal_title：Biometrics

authors： Li S,Gray RJ

更新日期：2016-09-01 00:00:00

abstract：:The validation of surrogate endpoints has been studied by Prentice (1989, Statistics in Medicine 8, 431-440) and Freedman, Graubard, and Schatzkin (1992, Statistics in Medicine 11, 167-178). We extended their proposals in the cases where the surrogate and the final endpoints are both binary or normally distributed. Le...

journal_title：Biometrics

authors： Buyse M,Molenberghs G

更新日期：1998-09-01 00:00:00

abstract：:We propose methods for Bayesian inference for a new class of semiparametric survival models with a cure fraction. Specifically, we propose a semiparametric cure rate model with a smoothing parameter that controls the degree of parametricity in the right tail of the survival distribution. We show that such a parameter ...

journal_title：Biometrics

authors： Ibrahim JG,Chen MH,Sinha D

更新日期：2001-06-01 00:00:00

abstract：:The search for an optimal dose of a drug has been investigated in a sequential setting to ensure the safety level by Eichhorn and Zacks (1973, Journal of the American Statistical Association 68, 594-598; 1981, Communications in Statistics--Theory and Methods A10, 931-953), Eichhorn (1974, Communications in Statistics ...

journal_title：Biometrics

authors： Shih WJ

更新日期：1989-06-01 00:00:00

abstract：:We describe a Bayesian quantile regression model that uses a confirmatory factor structure for part of the design matrix. This model is appropriate when the covariates are indicators of scientifically determined latent factors, and it is these latent factors that analysts seek to include as predictors in the quantile ...

journal_title：Biometrics

authors： Burgette LF,Reiter JP

更新日期：2012-03-01 00:00:00

abstract：:For many long-lived animal species, individuals do not breed every year, and are often not accessible during non-breeding periods. Individuals exhibit site fidelity if they return to the same breeding colony or spawning ground when they breed. If capture and recapture is only possible at the breeding site, temporary e...

journal_title：Biometrics

authors： Pledger S,Baker E,Scribner K

更新日期：2013-12-01 00:00:00

abstract：:It has become increasingly common in epidemiological studies to pool specimens across subjects to achieve accurate quantitation of biomarkers and certain environmental chemicals. In this article, we consider the problem of fitting a binary regression model when an important exposure is subject to pooling. We take a re...

journal_title：Biometrics

authors： Zhang Z,Albert PS

更新日期：2011-06-01 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

authors： Ruberg SJ,Stegeman JW

更新日期：1991-09-01 00:00:00

abstract：:In the genetic study of complex traits, especially behavior related ones, such as smoking and alcoholism, usually several phenotypic measurements are obtained for the description of the complex trait, but no single measurement can quantify fully the complicated characteristics of the symptom because of our lack of und...

journal_title：Biometrics

authors： Yu K,Wheeler W,Li Q,Bergen AW,Caporaso N,Chatterjee N,Chen J

更新日期：2010-03-01 00:00:00

abstract：:Some covariate-adaptive randomization methods have been used in clinical trials for a long time, but little theoretical work has been done about testing hypotheses under covariate-adaptive randomization until Shao et al. (2010) who provided a theory with detailed discussion for responses under linear models. In this a...

journal_title：Biometrics

authors： Shao J,Yu X

更新日期：2013-12-01 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：:Genomic data are often characterized by a moderate to large number of categorical variables observed for relatively few subjects. Some of the variables may be missing or noninformative. An example of such data is loss of heterozygosity (LOH), a dichotomous variable, observed on a moderate number of genetic markers. We...

journal_title：Biometrics

authors： Houseman EA,Coull BA,Betensky RA

更新日期：2006-12-01 00:00:00

abstract：:Heart rate oscillates in synchrony with respiration. Several methods have been employed to assess this 'sinus arrhythmia', as an index of autonomic nervous system function. This paper proposes a new, easily computed measure, R, which is relatively resistant to the major nonrespiratory sources of variation, including p...

journal_title：Biometrics

authors： Weinberg CR,Pfeifer MA

更新日期：1984-09-01 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

authors： Langenberg P,Srinivasan R

更新日期：1981-03-01 00:00:00

abstract：:Many statistical tests have been proposed for case-control data to detect disease association with multiple single nucleotide polymorphisms (SNPs) in linkage disequilibrium. The main reason for the existence of so many tests is that each test aims to detect one or two aspects of many possible distributional difference...

journal_title：Biometrics

authors： Han F,Pan W

更新日期：2012-03-01 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：:The relative performance of the unconditioned maximum likelihood estimators (UMLEs), conditional MLEs (CMLEs), and Jewell-type estimators of the odds ratio (OR) and its logarithm were investigated in sets of single 2 x 2 contingency tables. The tables were generated by complete enumeration of all possible cell frequen...

journal_title：Biometrics

authors： Walter SD,Cook RJ

更新日期：1991-09-01 00:00:00

abstract：:We present an approach for analyzing internal dependencies in counting processes. This covers the case with repeated events on each of a number of individuals, and more generally, the situation where several processes are observed for each individual. We define dynamic covariates, i.e., covariates depending on the pas...

journal_title：Biometrics

authors： Aalen OO,Fosen J,Weedon-Fekjaer H,Borgan O,Husebye E

更新日期：2004-09-01 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

authors： McLachlan GJ,Jones PN

更新日期：1988-06-01 00:00:00

abstract：:Differential equations are extensively used for modeling dynamics of physical processes in many scientific fields such as engineering, physics, and biomedical sciences. Parameter estimation of differential equation models is a challenging problem because of high computational cost and high-dimensional parameter space....

journal_title：Biometrics

authors： Wu H,Xue H,Kumar A

更新日期：2012-06-01 00:00:00