A pairwise pseudo-likelihood approach for left-truncated and interval-censored data under the Cox model.

abstract：:The method based on the Kolmogorov backward equations of Little (1995, Biometrics 51, 1278-1291) for computing hazard functions for the multistage carcinogenesis models fails when model parameters are time-dependent. In addition to suggesting an alternative method based on the Kolmogorov forward equation, this note hi...

journal_title：Biometrics

authors： Zheng Q

更新日期：1998-03-01 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：:We present a class of simple designs that can be used in early dose-finding studies in HIV. Such designs, in contrast with Phase I designs in cancer, have a lot of the Phase II flavor about them. Information on efficacy is obtained during the trial and is as important as that relating to toxicity. The designs proposed...

journal_title：Biometrics

authors： O'Quigley J,Hughes MD,Fenton T

更新日期：2001-12-01 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：:Let Yi be an ni X 1 vector of observations, Xi an ni X p matrix of known values, and beta an unknown p X 1 with the structure Yi = Xi beta + epsilon i, where the covariance matrix of epsilon i is of intra-class form, that is Cov (epsilon i) = sigma2[(1 - rho) Ii + rho e i e i'] where Ii is the ni X ni identity matrix ...

journal_title：Biometrics

authors： Wiorkowski JJ

更新日期：1975-09-01 00:00:00

abstract：:We describe a logistic-bivariate normal mixture model for a two-state Markov chain in which each individual makes transitions between states according to a subject-specific transition probability matrix. The use of the bivariate normal mixing distribution facilitates inferences regarding the correlation of the random ...

journal_title：Biometrics

authors： Cook RJ,Ng ET

更新日期：1997-03-01 00:00:00

abstract：:Case-control studies offer a rapid and efficient way to evaluate hypotheses. On the other hand, proper selection of the controls is challenging, and the potential for selection bias is a major weakness. Valid inferences about parameters of interest cannot be drawn if selection bias exists. Furthermore, the selection b...

journal_title：Biometrics

authors： Lin IF,Paik MC

更新日期：2001-12-01 00:00:00

abstract：:Dose-response models are intensively used in herbicide bioassays. Despite recent advancements in the development of new herbicides, statistical analyses are commonly based on asymptotic approximations that are sometimes poor. This paper presents the use of recent results in higher order asymptotics for likelihood-base...

journal_title：Biometrics

authors： Bellio R,Jensen JE,Seiden P

更新日期：2000-12-01 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：: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 recent years, increasing attention has been devoted to the problem of the stability of multivariable regression models, understood as the resistance of the model to small changes in the data on which it has been fitted. Resampling techniques, mainly based on the bootstrap, have been developed to address this issue....

journal_title：Biometrics

authors： De Bin R,Janitza S,Sauerbrei W,Boulesteix AL

更新日期：2016-03-01 00:00:00

abstract：:We propose a method to estimate the regression coefficients in a competing risks model where the cause-specific hazard for the cause of interest is related to covariates through a proportional hazards relationship and when cause of failure is missing for some individuals. We use multiple imputation procedures to imput...

journal_title：Biometrics

authors： Lu K,Tsiatis AA

更新日期：2001-12-01 00:00:00

abstract：:Exposure to high levels of air pollution during the pregnancy is associated with increased probability of preterm birth (PTB), a major cause of infant morbidity and mortality. New statistical methodology is required to specifically determine when a particular pollutant impacts the PTB outcome, to determine the role of...

journal_title：Biometrics

authors： Warren J,Fuentes M,Herring A,Langlois P

更新日期：2012-12-01 00:00:00

abstract：:Experimental designs that include repeated measures of binary response variables over time and under different conditions are common in biology. In such settings, it is often desirable to characterize the response pattern over time. When response variables are continuous, this characterization can be made in terms of ...

journal_title：Biometrics

authors： Stanek EJ 3rd,Diehl SR

更新日期：1988-12-01 00:00:00

abstract：SUMMARY:Nonparametric regression models are proposed in the framework of ecological inference for exploratory modeling of disease prevalence rates adjusted for variables, such as age, ethnicity/race, and socio-economic status. Ecological inference is needed when a response variable and covariate are not available at th...

journal_title：Biometrics

authors： Staniswalis JG

更新日期：2008-12-01 00:00:00

abstract：:A life table estimates probabilities of surviving and of dying as well as death rates, as these would apply in a stationary population with the same underlying continuous mortality curve as the observed population. We have derived approximations to the probability of surviving that require no iteration, do not depend ...

journal_title：Biometrics

authors： Keyfitz N,Frauenthal J

更新日期：1975-12-01 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：:In the field of cardio-thoracic surgery, valve function is monitored over time after surgery. The motivation for our research comes from a study which includes patients who received a human tissue valve in the aortic position. These patients are followed prospectively over time by standardized echocardiographic assess...

journal_title：Biometrics

authors： Andrinopoulou ER,Eilers PHC,Takkenberg JJM,Rizopoulos D

更新日期：2018-06-01 00:00:00

abstract：:We consider a semiparametric regression model that relates a normal outcome to covariates and a genetic pathway, where the covariate effects are modeled parametrically and the pathway effect of multiple gene expressions is modeled parametrically or nonparametrically using least-squares kernel machines (LSKMs). This un...

journal_title：Biometrics

authors： Liu D,Lin X,Ghosh D

更新日期：2007-12-01 00:00:00

abstract：:Zhao and Tsiatis (1997) consider the problem of estimation of the distribution of the quality-adjusted lifetime when the chronological survival time is subject to right censoring. The quality-adjusted lifetime is typically defined as a weighted sum of the times spent in certain states up until death or some other fail...

journal_title：Biometrics

authors： van der Laan MJ,Hubbard A

更新日期：1999-06-01 00:00:00

abstract：:At any age the mean residual life function gives the expected remaining life at that age. Reliabilists and biometricians have found it useful to categorize failure distributions by the monotonicity properties of the mean residual life function. Hollander and Proschan (1975, Biometrika 62, 585-593) have derived tests o...

journal_title：Biometrics

authors： Chen YY,Hollander M,Langberg NA

更新日期：1983-03-01 00:00:00

abstract：:Serial dilution assays are widely employed for estimating substance concentrations and minimum inhibitory concentrations. The Poisson-Bernoulli model for such assays is appropriate for count data but not for continuous measurements that are encountered in applications involving substance concentrations. This paper pre...

journal_title：Biometrics

authors： Lee ML,Whitmore GA

更新日期：1999-12-01 00:00:00

abstract：:Estimating the number of clusters in a data set is a crucial step in cluster analysis. In this article, motivated by the gap method (Tibshirani, Walther, and Hastie, 2001, Journal of the Royal Statistical Society B63, 411-423), we propose the weighted gap and the difference of difference-weighted (DD-weighted) gap met...

journal_title：Biometrics

authors： Yan M,Ye K

更新日期：2007-12-01 00:00:00

abstract：:A transformed Bernstein polynomial that is centered at standard parametric families, such as Weibull or log-logistic, is proposed for use in the accelerated hazards model. This class provides a convenient way towards creating a Bayesian nonparametric prior for smooth densities, blending the merits of parametric and no...

journal_title：Biometrics

authors： Chen Y,Hanson T,Zhang J

更新日期：2014-03-01 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：:With the internet, a massive amount of information on species abundance can be collected by citizen science programs. However, these data are often difficult to use directly in statistical inference, as their collection is generally opportunistic, and the distribution of the sampling effort is often not known. In this...

journal_title：Biometrics

authors： Giraud C,Calenge C,Coron C,Julliard R

更新日期：2016-06-01 00:00:00

abstract：:Most existing methods for identifying aberrant regions with array CGH data are confined to a single target sample. Focusing on the comparison of multiple samples from two different groups, we develop a new penalized regression approach with a fused adaptive lasso penalty to accommodate the spatial dependence of the cl...

journal_title：Biometrics

authors： Wang HJ,Hu J

更新日期：2011-06-01 00:00:00

abstract：:The spending function approach proposed by Lan and DeMets (1983, Biometrika 70, 659-663) for sequential monitoring of clinical trials is applied to situations where comparison of changes in a continuous response variable between two groups is the primary concern. Death, loss to follow-up, and missed visits could cause...

journal_title：Biometrics

authors： Wu MC,Lan KK

更新日期：1992-09-01 00:00:00

abstract：:When testing the null hypothesis that treatment arm-specific survival-time distributions are equal, the log-rank test is asymptotically valid when the distribution of time to censoring is conditionally independent of randomized treatment group given survival time. We introduce a test of the null hypothesis for use whe...

journal_title：Biometrics

authors： DiRienzo AG

更新日期：2003-09-01 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