Abstract:
:In many applications of generalized linear mixed models to multilevel data, it is of interest to test whether a random effects variance component is zero. It is well known that the usual asymptotic chi-square distribution of the likelihood ratio and score statistics under the null does not necessarily hold. In this note we propose a permutation test, based on randomly permuting the indices associated with a given level of the model, that has the correct Type I error rate under the null. Results from a simulation study suggest that it is more powerful than tests based on mixtures of chi-square distributions. The proposed test is illustrated using data on the familial aggregation of sleep disturbance.
journal_name
Biometricsjournal_title
Biometricsauthors
Fitzmaurice GM,Lipsitz SR,Ibrahim JGdoi
10.1111/j.1541-0420.2007.00775.xsubject
Has Abstractpub_date
2007-09-01 00:00:00pages
942-6issue
3eissn
0006-341Xissn
1541-0420pii
BIOM775journal_volume
63pub_type
杂志文章相关文献
BIOMETRICS文献大全abstract::This paper proposes a two-stage phase I-II clinical trial design to optimize dose-schedule regimes of an experimental agent within ordered disease subgroups in terms of the toxicity-efficacy trade-off. The design is motivated by settings where prior biological information indicates it is certain that efficacy will imp...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13116
更新日期:2020-03-01 00:00:00
abstract::Interference occurs when the treatment of one person affects the outcome of another. For example, in infectious diseases, whether one individual is vaccinated may affect whether another individual becomes infected or develops disease. Quantifying such indirect (or spillover) effects of vaccination could have important...
journal_title:Biometrics
pub_type: 杂志文章,随机对照试验
doi:10.1111/biom.12184
更新日期:2014-09-01 00:00:00
abstract::A study of otitis media that requires a test for the comparison of two clustered samples of censored data is described. A method is proposed taking into account the within-subject correlation in the formation of the log-rank statistic. ...
journal_title:Biometrics
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:1996-03-01 00:00:00
abstract::The situation considered is the prediction of a future observation from a simple exponential survival distribution in a hierarchical Bayes context. It is shown that when the hyperparameters need to be estimated from the data, a sample reuse approach is superior to maximum likelihood and method of moments estimation pr...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1990-03-01 00:00:00
abstract::We study the issue of identifiability of mixture models in the context of capture-recapture abundance estimation for closed populations. Such models are used to take account of individual heterogeneity in capture probabilities, but their validity was recently questioned by Link (2003, Biometrics 59, 1123-1130) on the ...
journal_title:Biometrics
pub_type: 评论,杂志文章
doi:10.1111/j.1541-0420.2006.00637_1.x
更新日期:2006-09-01 00:00:00
abstract::ChIP-chip (or ChIP-on-chip) is a technology for isolation and identification of genomic sites occupied by specific DNA-binding proteins in living cells. The ChIP-chip signals can be obtained over the whole genome by tiling arrays, where a peak shape is generally observed around a protein-binding site. In this article,...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2007.00768.x
更新日期:2007-09-01 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
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2005.00378.x
更新日期:2005-12-01 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
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2001.00957.x
更新日期:2001-09-01 00:00:00
abstract::In clinical trials and other investigations of survival time, information is often available on a time-dependent event other than survival. An example of such an auxiliary event in cancer studies is objective progression of disease. While some patients expire without experiencing objective disease progression, others ...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1976-09-01 00:00:00
abstract::Microarray technology allows the monitoring of expression levels of thousands of genes simultaneously. A semiparametric location and scale model is proposed to model gene expression levels for normalization and significance analysis purposes. Robust estimation based on weighted least absolute deviation regression and ...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2005.00452.x
更新日期:2006-06-01 00:00:00
abstract::The distance between homologous DNA sequences of two species is proposed to be -1/4 ln[det(P)], where P is the conditional probability matrix specifying the proportions of the various nucleotides in the second sequence, corresponding to each of the four nucleotides in the first sequence. A probability model is describ...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1987-06-01 00:00:00
abstract::Treatments are frequently evaluated in terms of their effect on patient survival. In settings where randomization of treatment is not feasible, observational data are employed, necessitating correction for covariate imbalances. Treatments are usually compared using a hazard ratio. Most existing methods which quantify ...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12542
更新日期:2017-03-01 00:00:00
abstract::We propose a new estimation method for multivariate failure time data using the quadratic inference function (QIF) approach. The proposed method efficiently incorporates within-cluster correlations. Therefore, it is more efficient than those that ignore within-cluster correlation. Furthermore, the proposed method is e...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2009.01307.x
更新日期:2010-06-01 00:00:00
abstract::An efficient method is presented for analyses of death rated in one-way or cross-classified experiments where expected survival time for a patient at time of entry on trial is a function of observable covariates. The survival-time distribution used is a Weibull form of Cox's (1972) model. The analysis proceeds in two ...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1978-06-01 00:00:00
abstract::Variable selection for clustering is an important and challenging problem in high-dimensional data analysis. Existing variable selection methods for model-based clustering select informative variables in a "one-in-all-out" manner; that is, a variable is selected if at least one pair of clusters is separable by this va...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2009.01341.x
更新日期:2010-09-01 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
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2007.00822.x
更新日期:2007-12-01 00:00:00
abstract::We propose a Bayesian latent Ornstein-Uhlenbeck (OU) model to analyze unbalanced longitudinal data of binary and ordinal variables, which are manifestations of fewer continuous latent variables. We focus on the evolution of such latent variables when they continuously change over time. Existing approaches are limited ...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13292
更新日期:2020-05-11 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
pub_type: 临床试验,杂志文章
doi:10.1111/j.1541-0420.2005.00314.x
更新日期:2005-06-01 00:00:00
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
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2006.00612.x
更新日期:2006-12-01 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
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2007.00983.x
更新日期:2008-12-01 00:00:00
abstract::Bayesian methods are presented for assessing bioequivalence for studies in which a new formulation and a standard are administered simultaneously, and for Latin square designs which compare two or more new formulations to a standard. Two examples illustrate the application of the methods. ...
journal_title:Biometrics
pub_type: 临床试验,杂志文章
doi:
更新日期:1984-12-01 00:00:00
abstract:SUMMARY:We develop sample size formulas for studies aiming to test mean differences between a treatment and control group when all-or-none nonadherence (noncompliance) and selection bias are expected. Recent work by Fay, Halloran, and Follmann (2007, Biometrics 63, 465-474) addressed the increased variances within grou...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2008.01114.x
更新日期:2009-06-01 00:00:00
abstract::Inference for continuous time multi-state models presents considerable computational difficulties when the process is only observed at discrete time points with no additional information about the state transitions. In fact, for general multi-state Markov model, evaluation of the likelihood function is possible only v...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13019
更新日期:2019-09-01 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
pub_type: 临床试验,杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract::We assess the efficiency of balanced treatment allocation methods in clinical trials for comparing treatments with respect to survival. We compare optimal designs for each of three standard survival analysis techniques (maximum partial likelihood estimation, log-rank test, exponential regression) with balanced designs...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1988-09-01 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
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract::Prentice and Sheppard (1995, Biometrika 82, 113-125) proposed a method for estimating relative risks associated with poorly measured exposures using disease rates from multiple populations and exposure and confounding factor data from sample surveys of persons in each population. The method involved an assumption of i...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1998-12-01 00:00:00
abstract::Restricted maximum likelihood (REML) is now well established as a method for estimating the parameters of the general Gaussian linear model with a structured covariance matrix, in particular for mixed linear models. Conventionally, estimates of precision and inference for fixed effects are based on their asymptotic di...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1997-09-01 00:00:00
abstract::Whenever inference for variance components is required, the choice between one-sided and two-sided tests is crucial. This choice is usually driven by whether or not negative variance components are permitted. For two-sided tests, classical inferential procedures can be followed, based on likelihood ratios, score stati...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/1541-0420.00032
更新日期:2003-06-01 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
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2003.00116.x
更新日期:2003-12-01 00:00:00