A strategy for dose-finding and safety monitoring based on efficacy and adverse outcomes in phase I/II clinical trials.

abstract：:Epidemiological studies of related individuals are often complicated by the fact that follow-up on the event type of interest is incomplete due to the occurrence of other events. We suggest a class of frailty models with cause-specific hazards for correlated competing events in related individuals. The frailties are b...

journal_title：Biometrics

authors： Eriksson F,Scheike T

更新日期：2015-09-01 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

authors： Guo J,Levina E,Michailidis G,Zhu J

更新日期：2010-09-01 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：: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：:Dynamic treatment regimes (DTRs) aim to formalize personalized medicine by tailoring treatment decisions to individual patient characteristics. G-estimation for DTR identification targets the parameters of a structural nested mean model, known as the blip function, from which the optimal DTR is derived. Despite its po...

journal_title：Biometrics

authors： Wallace MP,Moodie EEM,Stephens DA

更新日期：2019-12-01 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：:Understanding HIV incidence, the rate at which new infections occur in populations, is critical for tracking and surveillance of the epidemic. In this article, we derive methods for determining sample sizes for cross-sectional surveys to estimate incidence with sufficient precision. We further show how to specify samp...

journal_title：Biometrics

authors： Konikoff J,Brookmeyer R

更新日期：2015-12-01 00:00:00

abstract：:We propose a new criterion for confounder selection when the underlying causal structure is unknown and only limited knowledge is available. We assume all covariates being considered are pretreatment variables and that for each covariate it is known (i) whether the covariate is a cause of treatment, and (ii) whether t...

journal_title：Biometrics

authors： VanderWeele TJ,Shpitser I

更新日期：2011-12-01 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：SUMMARY:We develop sample size formulas for studies aiming to test mean differences between a treatment and control group when all-or-none nonadherence (noncompliance) and selection bias are expected. Recent work by Fay, Halloran, and Follmann (2007, Biometrics 63, 465-474) addressed the increased variances within grou...

journal_title：Biometrics

authors： Shardell MD,El-Kamary SS

更新日期：2009-06-01 00:00:00

abstract：:Geographic disease surveillance methods identify regions that have higher disease rates than expected. These approaches are generally applied to incident or prevalent cases of disease. In some contexts, disease-related events rather than individuals are the appropriate units of analysis for geographic surveillance. We...

journal_title：Biometrics

authors： Rosychuk RJ,Huston C,Prasad NG

更新日期：2006-06-01 00:00:00

abstract：:A Bayesian multivariate adaptive regression spline fitting approach is used to model univariate and multivariate survival data with censoring. The possible models contain the proportional hazards model as a subclass and automatically detect departures from this. A reversible jump Markov chain Monte Carlo algorithm is ...

journal_title：Biometrics

authors： Mallick BK,Denison DG,Smith AF

更新日期：1999-12-01 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

authors： Haines LM

更新日期：2016-12-01 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：:Pharmacovigilance systems aim at early detection of adverse effects of marketed drugs. They maintain large spontaneous reporting databases for which several automatic signaling methods have been developed. One limit of those methods is that the decision rules for the signal generation are based on arbitrary thresholds...

journal_title：Biometrics

authors： Ahmed I,Dalmasso C,Haramburu F,Thiessard F,Broët P,Tubert-Bitter P

更新日期：2010-03-01 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：:The Wilcoxon rank sum test is widely used for two-group comparisons for nonnormal data. An assumption of this test is independence of sampling units both between and within groups. In ophthalmology, data are often collected on two eyes of an individual, which are highly correlated. In ophthalmological clinical trials,...

journal_title：Biometrics

authors： Rosner B,Glynn RJ,Lee ML

更新日期：2006-12-01 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

abstract：:Statistical models that include random effects are commonly used to analyze longitudinal and correlated data, often with the assumption that the random effects follow a Gaussian distribution. Via theoretical and numerical calculations and simulation, we investigate the impact of misspecification of this distribution o...

journal_title：Biometrics

authors： McCulloch CE,Neuhaus JM

更新日期：2011-03-01 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

abstract：:In family studies, canonical discriminant analysis can be used to find linear combinations of phenotypes that exhibit high ratios of between-family to within-family variabilities. But with large numbers of phenotypes, canonical discriminant analysis may overfit. To estimate the predicted ratios associated with the coe...

journal_title：Biometrics

authors： Jin M,Fang Y

更新日期：2011-03-01 00:00:00

abstract：:Detecting changes in longitudinal data is important in medical research. However, the existence of measurement outliers can cause an unexpected increase in the false alarm rate in claiming changes. To reduce the outliers, a new method has been developed. In this scheme, two measures are initially taken and, if they ar...

journal_title：Biometrics

authors： Namgung YY,Yang MC

更新日期：1994-03-01 00:00:00

abstract：:High throughput technologies, such as gene expression arrays and protein mass spectrometry, allow one to simultaneously evaluate thousands of potential biomarkers that could distinguish different tissue types. Of particular interest here is distinguishing between cancerous and normal organ tissues. We consider statist...

journal_title：Biometrics

authors： Pepe MS,Longton G,Anderson GL,Schummer M

更新日期：2003-03-01 00:00:00

abstract：:We describe group sequential tests for a bivariate response. The tests are defined in terms of the two response components jointly, rather than through a single summary statistic. Such methods are appropriate when the two responses concern different aspects of a treatment; for example, one might wish to show that a ne...

journal_title：Biometrics

authors： Jennison C,Turnbull BW

更新日期：1993-09-01 00:00:00

abstract：:In this article, we propose a graphical technique for assessing the goodness-of-fit of a stationary hidden Markov model (HMM). We show that plots of the estimated distribution against the empirical distribution detect lack of fit with high probability for large sample sizes. By considering plots of the univariate and ...

journal_title：Biometrics

authors： MacKay Altman R

更新日期：2004-06-01 00:00:00

abstract：:Andersen et al. (1985, Biometrics 41, 921-932) gave an estimator of the cumulative relative mortality comparing rates of death in an epidemiologic cohort to an external population as a function of time when covariate information is available on all cohort members. We present an analogous estimator when covariate infor...

journal_title：Biometrics

authors： Borgan O,Langholz B

更新日期：1993-06-01 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：: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

authors： Yasui Y,Pepe M,Hsu L,Adam BL,Feng Z

更新日期：2004-03-01 00:00:00

abstract：:Tsiatis, Rosner, and Mehta (1984, Biometrics 40, 797-803) proposed a procedure for constructing confidence intervals following group sequential tests of a normal mean. This method is first extended for group sequential tests for which the sample sizes between interim analyses are not identical or the times are not equ...

journal_title：Biometrics

authors： Kim K,DeMets DL

更新日期：1987-12-01 00:00:00

abstract：:We develop a Bayesian nonparametric mixture modeling framework for quantal bioassay settings. The approach is built upon modeling dose-dependent response distributions. We adopt a structured nonparametric prior mixture model, which induces a monotonicity restriction for the dose-response curve. Particular emphasis is ...

journal_title：Biometrics

authors： Fronczyk K,Kottas A

更新日期：2014-03-01 00:00:00