A stochastic model for the occurrence of transient ischemic attacks.

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：: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：:Joint models are formulated to investigate the association between a primary endpoint and features of multiple longitudinal processes. In particular, the subject-specific random effects in a multivariate linear random-effects model for multiple longitudinal processes are predictors in a generalized linear model for pr...

journal_title：Biometrics

authors： Li E,Wang N,Wang NY

更新日期：2007-12-01 00:00:00

abstract：:Five procedures are considered for the comparison of two or more multivariate samples. These procedures include a newly proposed nonparametric rank-sum test and a generalized least squares test. Also considered are the following tests: ordinary least squares, Hotelling's T2, and a Bonferroni per-experiment error-rate ...

journal_title：Biometrics

authors： O'Brien PC

更新日期：1984-12-01 00:00:00

abstract：:Studies using a series of increasing doses of a compound, including a zero dose control, are often conducted to study the effect of the compound on the response of interest. For a one-way design, Tukey et al. (1985, Biometrics 41, 295-301) suggested assessing trend by examining the slopes of regression lines under ari...

journal_title：Biometrics

authors： Quan H,Capizzi T

更新日期：1999-06-01 00:00:00

abstract：:Currently, the design of group sequential clinical trials requires choosing among several distinct design categories, design scales, and strategies for determining stopping rules. This approach can limit the design selection process so that clinical issues are not fully addressed. This paper describes a family of desi...

journal_title：Biometrics

authors： Kittelson JM,Emerson SS

更新日期：1999-09-01 00:00:00

abstract：:Although the analysis of censored survival data using the proportional hazards and linear regression models is common, there has been little work examining the ability of these estimators to predict time to failure. This is unfortunate, since a predictive plot illustrating the relationship between time to failure and ...

journal_title：Biometrics

authors： Heller G,Simonoff JS

更新日期：1992-03-01 00:00:00

abstract：:A log-linear model for estimating the size of a closed population is defined for inverse multiple-recapture sampling with dependent samples. Efficient estimators of the log-linear model parameters and the population size are obtained by the method of minimum chi-square. A chi-square test of the general linear hypothes...

journal_title：Biometrics

authors： Bonett DG,Woodward JA,Bentler PM

更新日期：1987-12-01 00:00:00

abstract：:Although the primary focus of Phase I clinical trials is to assess clinical pharmacology and possible toxicities, any information on the potential effect of treatment would be useful in helping to determine priorities between treatments for further study. We consider the scenario where data are routinely collected on ...

journal_title：Biometrics

authors： Lin HM,Hughes MD

更新日期：1995-09-01 00:00:00

abstract：:A novel nonparametric regression model is developed for evaluating the covariate-specific accuracy of a continuous biological marker. Accurately screening diseased from nondiseased individuals and correctly diagnosing disease stage are critically important to health care on several fronts, including guiding recommenda...

journal_title：Biometrics

authors： Inácio de Carvalho V,de Carvalho M,Branscum AJ

更新日期：2017-12-01 00:00:00

abstract：:ChIP-chip (or ChIP-on-chip) is a technology for isolation and identification of genomic sites occupied by specific DNA-binding proteins in living cells. The ChIP-chip signals can be obtained over the whole genome by tiling arrays, where a peak shape is generally observed around a protein-binding site. In this article,...

journal_title：Biometrics

authors： Zheng M,Barrera LO,Ren B,Wu YN

更新日期：2007-09-01 00:00:00

abstract：:Three properties of interest in bioavailability studies using compartmental models are the area under the concentration curve, the maximum concentration, and the time to maximum concentration. Methods are described for finding designs that minimize the variance of the estimates of these quantities in such a model. The...

journal_title：Biometrics

authors： Atkinson AC,Chaloner K,Herzberg AM,Juritz J

更新日期：1993-06-01 00:00:00

abstract：:We propose optimal choice of the design parameters for random discontinuation designs (RDD) using a Bayesian decision-theoretic approach. We consider applications of RDDs to oncology phase II studies evaluating activity of cytostatic agents. The design consists of two stages. The preliminary open-label stage treats al...

journal_title：Biometrics

authors： Trippa L,Rosner GL,Müller P

更新日期：2012-03-01 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：: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：: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：:Left truncation commonly occurs in many areas, and many methods have been proposed in the literature for the analysis of various types of left-truncated failure time data. For the situation, a common approach is to conduct the analysis conditional on truncation times, and the method is relatively simple but may not be...

journal_title：Biometrics

authors： Wang P,Li D,Sun J

更新日期：2020-10-15 00:00:00

abstract：SUMMARY:We consider the analysis of clinical trials that involve randomization to an active treatment (T = 1) or a control treatment (T = 0), when the active treatment is subject to all-or-nothing compliance. We compare three approaches to estimating treatment efficacy in this situation: as-treated analysis, per-protoc...

journal_title：Biometrics

authors： Little RJ,Long Q,Lin X

更新日期：2009-06-01 00:00:00

abstract：:To evaluate diagnostic tests, one would ideally like to verify, for example, with a biopsy, the disease state of all subjects in a study. Often, however, no all subjects are verified. Previous methods for evaluation assume that the decision to verify depends only on recorded variables. Sometimes, particularly if the d...

journal_title：Biometrics

authors： Baker SG

更新日期：1995-03-01 00:00:00

abstract：:In the context of state-space modeling, conventional usage of the deviance information criterion (DIC) evaluates the ability of the model to predict an observation at time t given the underlying state at time t. Motivated by the failure of conventional DIC to clearly choose between competing multivariate nonlinear Bay...

journal_title：Biometrics

authors： Millar RB,McKechnie S

更新日期：2014-12-01 00:00:00

abstract：:Using genetic recombination data to make inferences about chiasmata on the tetrad during meiosis is a classic problem dating back to Weinstein's paper in 1936 (Genetics 21, 155-199). In the last few years, Weinstein's methods have been revived and applied to new problems, but a number of important statistical issues r...

journal_title：Biometrics

authors： Yu K,Feingold E

更新日期：2002-06-01 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：:The concentration of carbon monoxide in the blood of a cigarette smoker varies in response to the frequency and dose of CO delivered by the cigarettes he smokes and by the rate at which CO washes out of his blood. Moments of first passage times or exit times above a nominal threshold can be calculated using a stochast...

journal_title：Biometrics

authors： Marcus AH,Czajkowski S Jr

更新日期：1979-09-01 00:00:00

abstract：:In spatial surveys for estimating the density of objects in a survey region, systematic designs will generally yield lower variance than random designs. However, estimating the systematic variance is well known to be a difficult problem. Existing methods tend to overestimate the variance, so although the variance is g...

journal_title：Biometrics

authors： Fewster RM

更新日期：2011-12-01 00:00:00

abstract：:Traditional paradigms for clinical translation are challenged in settings where multiple contemporaneous therapeutic strategies have been identified as potentially beneficial. Platform trials have emerged as an approach for sequentially comparing multiple trials using a single protocol. The Ebola virus disease outbrea...

journal_title：Biometrics

authors： Kaizer AM,Hobbs BP,Koopmeiners JS

更新日期：2018-09-01 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：:Inference regarding the inclusion or exclusion of random effects in linear mixed models is challenging because the variance components are located on the boundary of their parameter space under the usual null hypothesis. As a result, the asymptotic null distribution of the Wald, score, and likelihood ratio tests will ...

journal_title：Biometrics

authors： Lee OE,Braun TM

更新日期：2012-06-01 00:00:00

abstract：:We consider Bayesian inference and model selection for prevalence estimation using a longitudinal two-phase design in which subjects initially receive a low-cost screening test followed by an expensive diagnostic test conducted on several occasions. The change in the subject's diagnostic probability over time is descr...

journal_title：Biometrics

authors： Erkanli A,Soyer R,Costello EJ

更新日期：1999-12-01 00:00:00

abstract：:Interval-censored failure time data occur in many fields such as demography, economics, medical research, and reliability and many inference procedures on them have been developed (Sun, 2006; Chen, Sun, and Peace, 2012). However, most of the existing approaches assume that the mechanism that yields interval censoring ...

journal_title：Biometrics

authors： Wang P,Zhao H,Sun J

更新日期：2016-12-01 00:00:00

abstract：:The distribution of health care payments to insurance plans has substantial consequences for social policy. Risk adjustment formulas predict spending in health insurance markets in order to provide fair benefits and health care coverage for all enrollees, regardless of their health status. Unfortunately, current risk ...

journal_title：Biometrics

authors： Zink A,Rose S

更新日期：2020-09-01 00:00:00