Multivariate bioassay, combination of bioassays, and Fieller's theorem.

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：: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：:Some failure time data come from a population that consists of some subjects who are susceptible to and others who are nonsusceptible to the event of interest. The data typically have heavy censoring at the end of the follow-up period, and a standard survival analysis would not always be appropriate. In such situation...

journal_title：Biometrics

authors： Sy JP,Taylor JM

更新日期：2000-03-01 00:00:00

abstract：:This paper presents an approach to handling missing covariates in the generalized estimating equation (GEE) model for binary outcomes when the probability of missingness depends on the observed outcomes and covariates. The proposed method is to replace the missing quantities in the estimating function with consistent ...

journal_title：Biometrics

authors： Xie F,Paik MC

更新日期：1997-12-01 00:00:00

abstract：:The search for an optimal dose of a drug has been investigated in a sequential setting to ensure the safety level by Eichhorn and Zacks (1973, Journal of the American Statistical Association 68, 594-598; 1981, Communications in Statistics--Theory and Methods A10, 931-953), Eichhorn (1974, Communications in Statistics ...

journal_title：Biometrics

authors： Shih WJ

更新日期：1989-06-01 00:00:00

abstract：:A model specified in terms of linear models for marginal logits and linear models for log-odds ratios is proposed for the analysis of two-period binary cross-over experiments. Hypothesis testing and parameter estimation are facilitated by standard likelihood methodology. Two examples are used to illustrate how the mod...

journal_title：Biometrics

authors： Becker MP,Balagtas CC

更新日期：1993-12-01 00:00:00

abstract：:For many long-lived animal species, individuals do not breed every year, and are often not accessible during non-breeding periods. Individuals exhibit site fidelity if they return to the same breeding colony or spawning ground when they breed. If capture and recapture is only possible at the breeding site, temporary e...

journal_title：Biometrics

authors： Pledger S,Baker E,Scribner K

更新日期：2013-12-01 00:00:00

abstract：:A formula is derived for determining the number of observations necessary to test the equality of two survival distributions when concomitant information is incorporated. This formula should be useful in designing clinical trials with a heterogeneous patient population. Schoenfeld (1981, Biometrika 68, 316-319) derive...

journal_title：Biometrics

authors： Schoenfeld DA

更新日期：1983-06-01 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：:Motivated by the particular problem of predicting defoliation based on a measure of gypsy moth egg mass density, prediction in the presence of measurement error is discussed. The measurement error variances and covariances are allowed to vary from unit to unit and are estimated by some type of within unit sampling. A ...

journal_title：Biometrics

authors： Buonaccorsi JP

更新日期：1995-12-01 00:00:00

abstract：:Gene-disease association studies based on case-control designs may often be used to identify candidate polymorphisms (markers) conferring disease risk. If a large number of markers are studied, genotyping all markers on all samples is inefficient in resource utilization. Here, we propose an alternative two-stage metho...

journal_title：Biometrics

authors： Satagopan JM,Venkatraman ES,Begg CB

更新日期：2004-09-01 00:00:00

abstract：:The approach to early termination for efficacy in a trial where events occur over time but the primary question of interest relates to a long-term binary endpoint is not straightforward. This article considers comparison of treatment groups with Kaplan-Meier (KM) proportions evaluated at increasing times from randomiz...

journal_title：Biometrics

authors： Brittain E,Follmann D,Yang S

更新日期：2008-03-01 00:00:00

abstract：:In this study we are concerned with the construction of confidence intervals for the conditional probability of misallocation associated with Anderson's classification statistics, W. The available methods of computing confidence intervals for the conditional probability are not satisfactory in practice, mainly because...

journal_title：Biometrics

authors： McLachlan GJ

更新日期：1975-03-01 00:00:00

abstract：:A recurring objective in longitudinal studies on aging and longevity has been the investigation of the relationship between age-at-death and current values of a longitudinal covariate trajectory that quantifies reproductive or other behavioral activity. We propose a novel technique for predicting age-at-death distribu...

journal_title：Biometrics

authors： Müller HG,Zhang Y

更新日期：2005-12-01 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：: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：:Observational studies are often in peril of unmeasured confounding. Instrumental variable analysis is a method for controlling for unmeasured confounding. As yet, theory on instrumental variable analysis of censored time-to-event data is scarce. We propose a pseudo-observation approach to instrumental variable analysi...

journal_title：Biometrics

authors： Kjaersgaard MI,Parner ET

更新日期：2016-06-01 00:00:00

abstract：:In this paper, a Markov process is developed as a mathematical model to study the general problem of quality control monitoring. This approach was previously used by Arnold (1970) in development of sampling plans to study the water quality monitoring of streams. Arnold considered the expected sample size required for ...

journal_title：Biometrics

authors： Smeach SC,Jernigan RW

更新日期：1977-03-01 00:00:00

abstract：:In this article, we develop new methods for estimating average treatment effects in observational studies, in settings with more than two treatment levels, assuming unconfoundedness given pretreatment variables. We emphasize propensity score subclassification and matching methods which have been among the most popular...

journal_title：Biometrics

authors： Yang S,Imbens GW,Cui Z,Faries DE,Kadziola Z

更新日期：2016-12-01 00:00:00

abstract：:In this note we propose a frailty model called piecewise gamma frailty for correlated survival data with random effects having a nested structure. In frailty models, a dependence function defined as a hazard ratio of one member given the failure time of another member in a unit is determined by the distributional assu...

journal_title：Biometrics

authors： Paik MC,Tsai WY,Ottman R

更新日期：1994-12-01 00:00:00

abstract：:This paper considers methods for estimating the relationship between a binary response Y and the genetic effects responsible for a second binary trait Z. The responses Y are observed only for target individuals, and the responses Z are observed only for the relatives of these targets. The analysis consists of two part...

journal_title：Biometrics

authors： Houwing-Duistermaat JJ,van Houwelingen HC,de Winter JP

更新日期：2000-09-01 00:00:00

abstract：:The use of the uniformly most powerful among the unbiased (UMPU) test was recently suggested for the study of gametic association between two polymorphic loci as an alternative to the Fisher's exact test (Zapata and Alvarez, 1997, Annals of Human Genetics 61, 71-77). However, the proposed test is not UMPU for two-side...

journal_title：Biometrics

authors： Fuchs C

更新日期：2001-06-01 00:00:00

abstract：:We propose a response-adaptive model for functional linear regression, which is adapted to sparsely sampled longitudinal responses. Our method aims at predicting response trajectories and models the regression relationship by directly conditioning the sparse and irregular observations of the response on the predictor,...

journal_title：Biometrics

authors： Wu S,Müller HG

更新日期：2011-09-01 00:00:00

abstract：:Brain connectivity analysis is now at the foreground of neuroscience research. A connectivity network is characterized by a graph, where nodes represent neural elements such as neurons and brain regions, and links represent statistical dependence that is often encoded in terms of partial correlation. Such a graph is i...

journal_title：Biometrics

authors： Xia Y,Li L

更新日期：2017-09-01 00:00:00

abstract：:In controlled clinical trials there are usually several prognostic factors known or thought to influence the patient's ability to respond to treatment. Therefore, the method of sequential treatment assignment needs to be designed so that treatment balance is simultaneously achieved across all such patients factor. Tra...

journal_title：Biometrics

authors： Pocock SJ,Simon R

更新日期：1975-03-01 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：:With advancements in technology, the collection of multiple types of measurements on a common set of subjects is becoming routine in science. Some notable examples include multimodal neuroimaging studies for the simultaneous investigation of brain structure and function and multi-omics studies for combining genetic an...

journal_title：Biometrics

authors： Zhao Y,Li L,Caffo BS

更新日期：2020-08-13 00:00:00

abstract：:In epidemiologic studies of time to an event, mean lifetime is often of direct interest. We propose methods to estimate group- (e.g., treatment-) specific differences in restricted mean lifetime for studies where treatment is not randomized and lifetimes are subject to both dependent and independent censoring. The pro...

journal_title：Biometrics

authors： Zhang M,Schaubel DE

更新日期：2011-09-01 00:00:00

abstract：:Phase I trials to study the pharmacokinetic properties of a new drug generally involve a restricted number of healthy volunteers. Because of the nature of the group involved in such studies, the appropriate distributional assumptions are not always obvious. These model assumptions include the actual distribution but a...

journal_title：Biometrics

authors： Lindsey JK,Byrom WD,Wang J,Jarvis P,Jones B

更新日期：2000-03-01 00:00:00

abstract：:Agricultural screening trials often involve a large number (t) of treatments in a complete block design with limited replication (b = 3 or 4 blocks). The null hypothesis of interest is that of no differences between treatments. For the commonly used analysis of variance (ANOVA) procedure, most texts do not discuss agr...

journal_title：Biometrics

authors： Brownie C,Boos DD

更新日期：1994-06-01 00:00:00