Estimation of completeness and adjustment of age-specific and age-standardized incidence rates.

abstract：:In this paper we consider the use of within-subject coefficient of variation (WCV) for assessing the reproducibility or reliability of a measurement. Application to assessing reproducibility of biochemical markers for measuring bone turnover is described and the comparison with intraclass correlation is discussed. Bot...

journal_title：Biometrics

authors： Quan H,Shih WJ

更新日期：1996-12-01 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：: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：:A simple method for comparing independent groups of clustered binary data with group-specific covariates is proposed. It is based on the concepts of design effect and effective sample size widely used in sample surveys, and assumes no specific models for the intracluster correlations. It can be implemented using any s...

journal_title：Biometrics

authors： Rao JN,Scott AJ

更新日期：1992-06-01 00:00:00

abstract：:Tag loss in mark-recapture experiments is a violation of one of the Jolly-Seber model assumptions. It causes bias in parameter estimates and has only been dealt with in an ad hoc manner. We develop methodology to estimate tag retention and abundance in double-tagging mark-recapture experiments. We apply this methodolo...

journal_title：Biometrics

authors： Cowen L,Schwarz CJ

更新日期：2006-09-01 00:00:00

abstract：:In this paper, a group sequential procedure for all-private comparisons of the means of k independent normal populations with a common known variance is proposed. A repeated range test is defined and its critical points are tabulated. The power function is studied and minimum group size needed to achieve a desirable p...

journal_title：Biometrics

authors： Liu W

更新日期：1995-09-01 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：:We propose a nonparametric Bayesian approach to estimate the natural direct and indirect effects through a mediator in the setting of a continuous mediator and a binary response. Several conditional independence assumptions are introduced (with corresponding sensitivity parameters) to make these effects identifiable f...

journal_title：Biometrics

authors： Daniels MJ,Roy JA,Kim C,Hogan JW,Perri MG

更新日期：2012-12-01 00:00:00

abstract：:Link et al. (2010, Biometrics 66, 178-185) define a general framework for analyzing capture-recapture data with potential misidentifications. In this framework, the observed vector of counts, y, is considered as a linear function of a vector of latent counts, x, such that y=Ax, with x assumed to follow a multinomial d...

journal_title：Biometrics

authors： Schofield MR,Bonner SJ

更新日期：2015-12-01 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：:Bayesian experimental design for a clinical trial involves specifying a utility function that models the purpose of the trial, in this case the selection of patients for a diagnostic test. The best sample of patients is selected by maximizing expected utility. This optimization task poses difficulties due to a high-di...

journal_title：Biometrics

authors： Buzoianu M,Kadane JB

更新日期：2009-09-01 00:00:00

abstract：:Combined maximum likelihood estimates for equicorrelation covariance matrices are considered. The case of a common equicorrelation rho and possibly different standard deviations sigma 1, ..., sigma k among k experimental groups is examined first, and the estimation of (rho, sigma 1, ..., sigma k) is discussed. Second,...

journal_title：Biometrics

authors： Viana MA

更新日期：1994-09-01 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：:This article presents a new approach for exploring the distribution of interindividual random effects in nonlinear mixed effect models. The approach introduces a spline function, which transforms an assumed normally distributed interindividual random effect to an arbitrary distribution approximating that of the data. ...

journal_title：Biometrics

authors： Fattinger KE,Sheiner LB,Verotta D

更新日期：1995-12-01 00:00:00

abstract：:For the case of repeated measures on Y with mean values linear in a concomitant variable Z in [a, b], a straight-line confidence band over [a, b] is given with width linear in Z. Graphical presentation of such line-segment confidence bands can help emphasize that appropriate inferences are limited to the range of the ...

journal_title：Biometrics

authors： Stewart PW

更新日期：1987-09-01 00:00:00

abstract：:Multivariate current status data, consist of indicators of whether each of several events occur by the time of a single examination. Our interest focuses on inferences about the joint distribution of the event times. Conventional methods for analysis of multiple event-time data cannot be used because all of the event ...

journal_title：Biometrics

authors： Dunson DB,Dinse GE

更新日期：2002-03-01 00:00:00

abstract：:The estimation of gene frequencies, linkage disequilibrium and disease associations for the human leukocyte antigen (HLA) system is considered. Comprehensive models for HLA data are introduced and contrasted with simpler approaches to the analysis of such data. ...

journal_title：Biometrics

authors： Farewell VT,Dahlberg S

更新日期：1984-06-01 00:00:00

abstract：:Inference regarding the inclusion or exclusion of random effects in linear mixed models is challenging because the variance components are located on the boundary of their parameter space under the usual null hypothesis. As a result, the asymptotic null distribution of the Wald, score, and likelihood ratio tests will ...

journal_title：Biometrics

authors： Lee OE,Braun TM

更新日期：2012-06-01 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 method is presented for choosing an additive constant c when transforming data x to y = log(x + c). The method preserves Type I error probability and power in ANOVA under the assumption that the x + c for some c are log-normally distributed. The method has advantages similar to those of rank transformations--namely,...

journal_title：Biometrics

authors： Berry DA

更新日期：1987-06-01 00:00:00

abstract：:Recent advances in human genetics have led to a renewed interest in statistical methods for the detection of linkage from family data--for example, between marker loci and disease traits. Statistical analysis of linkage between two loci is carried out almost exclusively by means of the lod (log-odds) score test, equiv...

journal_title：Biometrics

authors： Shoukri MM,Lathrop GM

更新日期：1993-03-01 00:00:00

abstract：:Currently, the design of group sequential clinical trials requires choosing among several distinct design categories, design scales, and strategies for determining stopping rules. This approach can limit the design selection process so that clinical issues are not fully addressed. This paper describes a family of desi...

journal_title：Biometrics

authors： Kittelson JM,Emerson SS

更新日期：1999-09-01 00:00:00

abstract：:The risks of conception, due to sexual intercourse at various times before and after the periovulatory rise in the woman's basal body temperature, are evaluated. In general, the risk is small nine or more days before, and two or more days after, the first day of elevated temperature. The model for the conception proba...

journal_title：Biometrics

authors： Royston JP

更新日期：1982-06-01 00:00:00

abstract：:This article develops a latent model and likelihood-based inference to detect temporal clustering of events. The model mimics typical processes generating the observed data. We apply model selection techniques to determine the number of clusters, and develop likelihood inference and a Monte Carlo expectation-maximizat...

journal_title：Biometrics

authors： Xie M,Sun Q,Naus J

更新日期：2009-12-01 00:00:00

abstract：:Cohort case-control design is an efficient and economical design to study risk factors for disease incidence or mortality in a large cohort. In the last few decades, a variety of cohort case-control designs have been developed and theoretically justified. These designs have been exclusively applied to the analysis of ...

journal_title：Biometrics

authors： Lu SE,Wang MC

更新日期：2002-12-01 00:00:00

abstract：SUMMARY:In this article we investigate regression calibration methods to jointly model longitudinal and survival data using a semiparametric longitudinal model and a proportional hazards model. In the longitudinal model, a biomarker is assumed to follow a semiparametric mixed model where covariate effects are modeled p...

journal_title：Biometrics

authors： Ye W,Lin X,Taylor JM

更新日期：2008-12-01 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：:Variable selection for recovering sparsity in nonadditive and nonparametric models with high-dimensional variables has been challenging. This problem becomes even more difficult due to complications in modeling unknown interaction terms among high-dimensional variables. There is currently no variable selection method ...

journal_title：Biometrics

authors： Fang Z,Kim I,Schaumont P

更新日期：2016-12-01 00:00:00

abstract：:As ultra high-dimensional longitudinal data are becoming ever more apparent in fields such as public health and bioinformatics, developing flexible methods with a sparse model is of high interest. In this setting, the dimension of the covariates can potentially grow exponentially as ...

journal_title：Biometrics

authors： Green B,Lian H,Yu Y,Zu T

更新日期：2020-08-04 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