Instrumental variable method for time-to-event data using a pseudo-observation approach.

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

authors： Hu J,Zhang L,Wang HJ

更新日期：2016-09-01 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：: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：:We consider hidden Markov models as a versatile class of models for weakly dependent random phenomena. The topic of the present paper is likelihood-ratio testing for hidden Markov models, and we show that, under appropriate conditions, the standard asymptotic theory of likelihood-ratio tests is valid. Such tests are c...

journal_title：Biometrics

authors： Giudici P,Rydén T,Vandekerkhove P

更新日期：2000-09-01 00:00:00

abstract：:Adaptive line transect sampling offers the potential of improved population density estimation efficiency over conventional line transect sampling when populations are spatially clustered. In adaptive sampling, survey effort is increased when areas of high animal density are located, thereby increasing the number of o...

journal_title：Biometrics

authors： Pollard JH,Palka D,Buckland ST

更新日期：2002-12-01 00:00:00

abstract：:In sampling certain types of materials, such as bags of fertilizer, or subsampling large quantities of water, as might be done in investigating the density of plankton in certain environmental situations, it is customary to composite the samples. That is, several samples are drawn, mixed into a composite sample, and a...

journal_title：Biometrics

authors： Rohde CA

更新日期：1976-06-01 00:00:00

abstract：:Pocock et al. (2012, European Heart Journal 33, 176-182) proposed a win ratio approach to analyzing composite endpoints comprised of outcomes with different clinical priorities. In this article, we establish a statistical framework for this approach. We derive the null hypothesis and propose a closed-form variance est...

journal_title：Biometrics

authors： Luo X,Tian H,Mohanty S,Tsai WY

更新日期：2015-03-01 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

authors： Blair RC,Sawilowsky S

更新日期：1993-09-01 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：:Traditional studies of short-term air pollution health effects use time series data, while cohort studies generally focus on long-term effects. There is increasing interest in exploiting individual level cohort data to assess short-term health effects in order to understand the mechanisms and time scales of action. We...

journal_title：Biometrics

authors： Szpiro AA,Sheppard L,Adar SD,Kaufman JD

更新日期：2014-03-01 00:00:00

abstract：:A class of adaptive weighted log-rank statistics is described where the vector of weights is chosen in a data-dependent way from a family of "smooth" weight vectors. A parametric family of weight vectors is identified which includes most shapes of weighting vectors that will be near optimal in many cancer prevention a...

journal_title：Biometrics

authors： Self SG

更新日期：1991-09-01 00:00:00

abstract：:Neuroendocrine ensembles communicate with their remote and proximal target cells via an intermittent pattern of chemical signaling. The identification of episodic releases of hormonal pulse signals constitutes a major emphasis of endocrine investigation. Estimating the number, temporal locations, secretion rate, and e...

journal_title：Biometrics

authors： Yang YC,Liu A,Wang Y

更新日期：2006-03-01 00:00:00

abstract：:Development of HIV resistance mutations is a major cause for failure of antiretroviral treatment. This article proposes a method for jointly modeling the processes of viral genetic changes and treatment failure. Because the viral genome is measured with uncertainty, a hidden Markov model is used to fit the viral genet...

journal_title：Biometrics

authors： Hu C,De Gruttola V

更新日期：2007-03-01 00:00:00

abstract：:A general theory for estimating the size of a closed population from multiple-recapture data is presented. This theory is easily extended to open population models for multiple-recapture data. Estimation is based on a log-linear model developed for modeling dependent capture-recapture data when capture probabilities v...

journal_title：Biometrics

authors： Evans MA,Bonett DG,McDonald LL

更新日期：1994-06-01 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：:Laska and Meisner (1989, Biometrics 45, 1139-1151) dealt with the problem of testing whether an identified treatment belonging to a set of k + 1 treatments is better than each of the other k treatments. They calculated sample size tables for k = 2 when using multiple t-tests or Wilcoxon-Mann-Whitney tests, both under ...

journal_title：Biometrics

authors： Horn M,Vollandt R,Dunnett CW

更新日期：2000-09-01 00:00:00

abstract：:This note discusses the use of capture-mark-recapture methods and log-linear, linear, product models for incomplete tables (Espeland, 1986, Communications in Statistics--Simulation and Computing 15, 405-424) to estimate completeness of reporting in a disease registry and to estimate incompleteness-adjusted incidence r...

journal_title：Biometrics

authors： Hilsenbeck SG,Kurucz C,Duncan RC

更新日期：1992-12-01 00:00:00

abstract：:The log-rank test is widely used to compare two survival distributions in a randomized clinical trial, while partial likelihood (Cox, 1975) is the method of choice for making inference about the hazard ratio under the Cox (1972) proportional hazards model. The Wald 95% confidence interval of the hazard ratio may inclu...

journal_title：Biometrics

authors： Lin DY,Dai L,Cheng G,Sailer MO

更新日期：2016-12-01 00:00:00

abstract：:Unless the true association is very strong, simple large-sample confidence intervals for the odds ratio based on the delta method perform well even for small samples. Such intervals include the Woolf logit interval and the related Gart interval based on adding .5 before computing the log odds ratio estimate and its st...

journal_title：Biometrics

authors： Agresti A

更新日期：1999-06-01 00:00:00

abstract：:We derive a likelihood score method for interval estimation of the intraclass version of the kappa coefficient of agreement with binary classification using a general theory of Bartlett (1953, Biometrika 40, 306-317). By exact evaluation, we investigate statistical properties of the score method, the chi-square goodne...

journal_title：Biometrics

authors： Nam JM

更新日期：2000-06-01 00:00:00

abstract：:A time-dependent measure, termed the rate ratio, was proposed to assess the local dependence between two types of recurrent event processes in one-sample settings. However, the one-sample work does not consider modeling the dependence by covariates such as subject characteristics and treatments received. The focus of ...

journal_title：Biometrics

authors： Ning J,Cai C,Chen Y,Huang X,Wang MC

更新日期：2020-12-01 00:00:00

abstract：:Dilution assays to determine solute concentration have found wide use in biomedical research. Many dilution assays return imprecise concentration estimates because they are only done to orders of magnitude. Previous statistical work has focused on how to design efficient experiments that can return more precise estima...

journal_title：Biometrics

authors： Ferguson JM,Miura TA,Miller CR

更新日期：2019-09-01 00:00:00

abstract：:In diagnostic medicine, estimating the diagnostic accuracy of a group of raters or medical tests relative to the gold standard is often the primary goal. When a gold standard is absent, latent class models where the unknown gold standard test is treated as a latent variable are often used. However, these models have b...

journal_title：Biometrics

authors： Zhang B,Chen Z,Albert PS

更新日期：2012-12-01 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 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：:We consider the problem of estimating a population size from successive catches taken during a removal experiment and propose two estimating functions approaches, the traditional quasi-likelihood (TQL) approach for dependent observations and the conditional quasi-likelihood (CQL) approach using the conditional mean an...

journal_title：Biometrics

authors： Wang YG

更新日期：1999-12-01 00:00:00

abstract：:This article describes the theoretical and practical issues in experimental design for gene expression microarrays. Specifically, this article 1) discusses the basic principles of design (randomization, replication, and blocking) as they pertain to microarrays, and 2) provides some general guidelines for statisticians...

journal_title：Biometrics

authors： Kerr MK

更新日期：2003-12-01 00:00:00

abstract：:In this article, we propose a Bayesian approach to phase I/II dose-finding oncology trials by jointly modeling a binary toxicity outcome and a continuous biomarker expression outcome. We apply our method to a clinical trial of a new gene therapy for bladder cancer patients. In this trial, the biomarker expression indi...

journal_title：Biometrics

authors： Bekele BN,Shen Y

更新日期：2005-06-01 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：:Identifying factors associated with increased medical cost is important for many micro- and macro-institutions, including the national economy and public health, insurers and the insured. However, assembling comprehensive national databases that include both the cost and individual-level predictors can prove challengi...

journal_title：Biometrics

authors： Johnson BA,Long Q,Huang Y,Chansky K,Redman M

更新日期：2016-09-01 00:00:00