Sample size methods for estimating HIV incidence from cross-sectional surveys.

abstract：:We consider a semiparametric inference procedure for data from epidemiologic studies conducted with a two-component sampling scheme where both a simple random sample and multiple outcome- or outcome-/auxiliary-dependent samples are observed. This sampling scheme allows the investigators to oversample certain subpopula...

journal_title：Biometrics

authors： Wang X,Zhou H

更新日期：2006-12-01 00:00:00

abstract：:Estimates of waterfowl demographic parameters often come from resighting studies where birds fit with individually identifiable neck collars are resighted at a distance. Concerns have been raised about the effects of collar loss on parameter estimates, and the reliability of extrapolating from collared individuals to ...

journal_title：Biometrics

authors： Conn PB,Kendall WL,Samuel MD

更新日期：2004-12-01 00:00:00

abstract：:Drawing inferences for high-dimensional models is challenging as regular asymptotic theories are not applicable. This article proposes a new framework of simultaneous estimation and inferences for high-dimensional linear models. By smoothing over partial regression estimates based on a given variable selection scheme,...

journal_title：Biometrics

authors： Fei Z,Zhu J,Banerjee M,Li Y

更新日期：2019-06-01 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：:There has been great interest in developing nonlinear structural equation models and associated statistical inference procedures, including estimation and model selection methods. In this paper a general semiparametric structural equation model (SSEM) is developed in which the structural equation is composed of nonpar...

journal_title：Biometrics

authors： Guo R,Zhu H,Chow SM,Ibrahim JG

更新日期：2012-06-01 00:00:00

abstract：:In large cohort studies, it often happens that some covariates are expensive to measure and hence only measured on a validation set. On the other hand, relatively cheap but error-prone measurements of the covariates are available for all subjects. Regression calibration (RC) estimation method (Prentice, 1982, Biometri...

journal_title：Biometrics

authors： Yu M,Nan B

更新日期：2010-06-01 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 longitudinal studies and in clustered situations often binary and continuous response variables are observed and need to be modeled together. In a recent publication Dunson, Chen, and Harry (2003, Biometrics 59, 521-530) (DCH) propose a Bayesian approach for joint modeling of cluster size and binary and continuous ...

journal_title：Biometrics

authors： Gueorguieva RV

更新日期：2005-09-01 00:00:00

abstract：:Within the framework of Fisher's discriminant analysis, we propose a multiclass classification method which embeds variable screening for ultrahigh-dimensional predictors. Leveraging interfeature correlations, we show that the proposed linear classifier recovers informative features with probability tending to one and...

journal_title：Biometrics

authors： Li Y,Hong HG,Li Y

更新日期：2019-12-01 00:00:00

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 mod...

journal_title：Biometrics

authors： Herring AH,Yang J

更新日期：2007-06-01 00:00:00

abstract：:Increasingly, genetic studies of tumors of the same histologic diagnosis are elucidating subtypes that are distinct with respect to clinical endpoints such as response to treatment and survival. This raises concerns about the efficiency of using the simple log-rank test for analysis of treatment effect on survival in ...

journal_title：Biometrics

authors： Li Y,Betensky RA,Louis DN,Cairncross JG

更新日期：2002-03-01 00:00:00

abstract：:The classical concordance correlation coefficient (CCC) to measure agreement among a set of observers assumes data to be distributed as normal and a linear relationship between the mean and the subject and observer effects. Here, the CCC is generalized to afford any distribution from the exponential family by means of...

journal_title：Biometrics

authors： Carrasco JL

更新日期：2010-09-01 00:00:00

abstract：:An estimator proposed by Greenland and Holland (1991, Biometrics 47, 319-322) for a standardized risk difference parameter is shown to be a maximum likelihood estimator if the consistent estimator of the common odds ratio is appropriately chosen. The statistical problem under consideration is reparameterized. Likeliho...

journal_title：Biometrics

authors： Yu KF

更新日期：1992-09-01 00:00:00

abstract：:Patients who were previously treated for prostate cancer with radiation therapy are monitored at regular intervals using a laboratory test called Prostate Specific Antigen (PSA). If the value of the PSA test starts to rise, this is an indication that the prostate cancer is more likely to recur, and the patient may wis...

journal_title：Biometrics

authors： Taylor JM,Park Y,Ankerst DP,Proust-Lima C,Williams S,Kestin L,Bae K,Pickles T,Sandler H

更新日期：2013-03-01 00:00:00

abstract：:Missing values appear very often in many applications, but the problem of missing values has not received much attention in testing order-restricted alternatives. Under the missing at random (MAR) assumption, we impute the missing values nonparametrically using kernel regression. For data with imputation, the classica...

journal_title：Biometrics

authors： Wang H,Zhong PS

更新日期：2017-09-01 00:00:00

abstract：:Petersen-type mark-recapture experiments are often used to estimate the number of fish or other animals in a population moving along a set migration route. A first sample of individuals is captured at one location, marked, and returned to the population. A second sample is then captured farther along the route, and in...

journal_title：Biometrics

authors： Bonner SJ,Schwarz CJ

更新日期：2011-12-01 00:00:00

abstract：:A ranked set sampling procedure with unequal samples (RSSU) is proposed and used to estimate the population mean. This estimator is then compared with the estimators based on the ranked set sampling (RSS) and median ranked set sampling (MRSS) procedures. It is shown that the relative precisions of the estimator based ...

journal_title：Biometrics

authors： Bhoj DS

更新日期：2001-09-01 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：: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：:Johnson and Wehrly (1978, Journal of the American Statistical Association 73, 602-606) and Wehrly and Johnson (1980, Biometrika 67, 255-256) show one way to construct the joint distribution of a circular and a linear random variable, or the joint distribution of a pair of circular random variables from their marginal ...

journal_title：Biometrics

authors： Fernández-Durán JJ

更新日期：2007-06-01 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：:Objective measures of oxygen consumption and carbon dioxide production by mammals are used to predict their energy expenditure. Since energy expenditure is not directly observable, it can be viewed as a latent construct with multiple physical indirect measures such as respiratory quotient, volumetric oxygen consumptio...

journal_title：Biometrics

authors： Tekwe CD,Zoh RS,Bazer FW,Wu G,Carroll RJ

更新日期：2018-03-01 00:00:00

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

authors： Altomare D,Consonni G,La Rocca L

更新日期：2013-06-01 00:00:00

abstract：:In this paper we propose a new class of statistics to test a simple hypothesis against a family of alternatives characterized by a mixture model. Unlike the likelihood ratio statistic, whose large sample distribution is still unknown in this situation, these new statistics have a simple asymptotic distribution to whic...

journal_title：Biometrics

authors： Liang KY,Rathouz PJ

更新日期：1999-03-01 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：:The problem of regression dilution arising from covariate measurement error is investigated for survival data using the proportional hazards model. The naive approach to parameter estimation is considered whereby observed covariate values are used, inappropriately, in the usual analysis instead of the underlying covar...

journal_title：Biometrics

authors： Hughes MD

更新日期：1993-12-01 00:00:00

abstract：:Genetic variants associated with disease outcomes can be used to develop personalized treatment. To reach this precision medicine goal, hundreds of large-scale genome-wide association studies (GWAS) have been conducted in the past decade to search for promising genetic variants associated with various traits. They hav...

journal_title：Biometrics

authors： Masotti M,Guo B,Wu B

更新日期：2019-12-01 00:00:00

abstract：:Consider a collection of spatially clustered objects where the clusters are geographically rare. Of interest is estimation of the total number of objects on the site from a sample of plots of equal size. Under these spatial conditions, adaptive cluster sampling of plots is generally useful in improving efficiency in e...

journal_title：Biometrics

authors： Christman MC,Pontius JS

更新日期：2000-06-01 00:00:00

abstract：:Suppose that the response variable in a well-executed clinical or observational study to evaluate a treatment is the time to a certain event, and a set of baseline covariates or predictors was collected for each study patient. Furthermore, suppose that a significant number of study patients had nontrivial, long-term a...

journal_title：Biometrics

authors： Tian L,Wang W,Wei LJ

更新日期：2003-12-01 00:00:00

abstract：:In this article, we investigate clustering methods for multilevel functional data, which consist of repeated random functions observed for a large number of units (e.g., genes) at multiple subunits (e.g., bacteria types). To describe the within- and between variability induced by the hierarchical structure in the data...

journal_title：Biometrics

authors： Serban N,Jiang H

更新日期：2012-09-01 00:00:00