Analysis of incomplete multivariate data using linear models with structured covariance matrices.

abstract：:Few methods are currently available for group sequential analysis of recurrent events data subject to a terminal event in the clinical trial setting. This research helps fill this gap by developing a completely nonparametric group sequential monitoring procedure for use with the two-sample Tayob and Murray statistic. ...

journal_title：Statistics in medicine

authors： Xia M,Murray S,Tayob N

更新日期：2019-12-30 00:00:00

abstract：:In different fields of applications including, but not limited to, behavioral, environmental, medical sciences, and econometrics, the use of panel data regression models has become increasingly popular as a general framework for making meaningful statistical inferences. However, when the ordinary least squares (OLS) m...

journal_title：Statistics in medicine

authors： Hamiye Beyaztas B,Bandyopadhyay S

更新日期：2020-12-20 00:00:00

abstract：:This paper discusses regression analysis of multivariate current status failure time data (The Statistical Analysis of Interval-censoring Failure Time Data. Springer: New York, 2006), which occur quite often in, for example, tumorigenicity experiments and epidemiologic investigations of the natural history of a diseas...

journal_title：Statistics in medicine

authors： Chen MH,Tong X,Sun J

更新日期：2009-11-30 00:00:00

abstract：:Health surveillance involves collecting public health data on chronic and infectious diseases to detect changes in disease incidence rates in order to improve public health. Timely detection of disease clusters is essential in prospective public health surveillance. Most existing health surveillance research is based ...

journal_title：Statistics in medicine

authors： Jiang W,Han SW,Tsui KL,Woodall WH

更新日期：2011-02-28 00:00:00

abstract：:Binary matched-pairs data occur commonly in longitudinal studies, such as in cross-over experiments. Many analyses for comparing the matched probabilities of a particular outcome do not utilize pairs having the same outcome for each observation. An example is McNemar's test. Some methodologists find this to be counter...

journal_title：Statistics in medicine

authors： Agresti A,Min Y

更新日期：2004-01-15 00:00:00

abstract：:Case-control studies are prone to low power for testing gene-environment interactions (GXE) given the need for a sufficient number of individuals on each strata of disease, gene, and environment. We propose a new study design to increase power by strategically pooling biospecimens. Pooling biospecimens allows us to in...

journal_title：Statistics in medicine

authors： Danaher MR,Schisterman EF,Roy A,Albert PS

更新日期：2012-11-20 00:00:00

abstract：:Quantifying socioeconomic disparities and understanding the roots of inequalities are growing topics in cancer research. However, socioeconomic differences are challenging to investigate mainly due to the lack of accurate data at individual-level, while aggregate indicators are only partially informative. We implement...

journal_title：Statistics in medicine

authors： Mezzetti M,Palli D,Dominici F

更新日期：2020-01-15 00:00:00

abstract：:Orthogonal polynomial scores (OPS) is a simple, biologically meaningful approach to characterize longitudinal data in phase I and II clinical pharmacology trials. It describes average, linear, quadratic and higher order polynomial characteristics of each subject's response over time with use of composite scores comput...

journal_title：Statistics in medicine

authors： Bradstreet TE

更新日期：1993-04-15 00:00:00

abstract：:This paper presents a simple method for estimation of population vaccination effectiveness, which is the fraction of disease cases prevented by a vaccination programme. The method is based on the susceptible-infectious-recovered (SIR) model for the spread of an epidemic in a heterogeneous population under non-homogene...

journal_title：Statistics in medicine

authors： Haber M

更新日期：1997-03-30 00:00:00

abstract：:Genome-wide association studies are characterized by a huge number of statistical tests performed to discover new disease-related genetic variants [in the form of single-nucleotide polymorphisms (SNPs)] in human DNA. Many SNPs have been identified for cross-sectionally measured phenotypes. However, there is a growing ...

journal_title：Statistics in medicine

authors： Sikorska K,Rivadeneira F,Groenen PJ,Hofman A,Uitterlinden AG,Eilers PH,Lesaffre E

更新日期：2013-01-15 00:00:00

abstract：:When sample size is recalculated using unblinded interim data, use of the usual t-test at the end of a study may lead to an elevated type I error rate. This paper describes a numerical quadrature investigation to calculate the true probability of rejection as a function of the time of the recalculation, the magnitude ...

journal_title：Statistics in medicine

authors： Wittes J,Schabenberger O,Zucker D,Brittain E,Proschan M

更新日期：1999-12-30 00:00:00

abstract：:In this study, 401 cases of childhood cancer in four California counties in 1980-1988 were analysed with the innovative methodology of density equalizing map projections. The data were originally collected and analysed by the California State Department of Health Services (DHS). In addition to the new analytic techniq...

journal_title：Statistics in medicine

authors： Merrill DW

更新日期：2001-05-15 00:00:00

abstract：:Subjective judgements of complex variables are commonly recorded as ordered categorical data. The rank-invariant properties of such data are well known, and there are various statistical approaches to the analysis and modelling of ordinal data. This paper focuses on the non-additive property of ordered categorical dat...

journal_title：Statistics in medicine

authors： Svensson E

更新日期：1998-12-30 00:00:00

abstract：:Sequential analysis is frequently employed to address ethical and financial issues in clinical trials. Sequential analysis may be performed using standard group sequential designs, or, more recently, with adaptive designs that use estimates of treatment effect to modify the maximal statistical information to be collec...

journal_title：Statistics in medicine

authors： Emerson SC,Rudser KD,Emerson SS

更新日期：2011-05-20 00:00:00

abstract：:The receiver operating characteristic (ROC) curve is a popular technique with applications, for example, investigating an accuracy of a biomarker to delineate between disease and non-disease groups. A common measure of accuracy of a given diagnostic marker is the area under the ROC curve (AUC). In contrast with the AU...

journal_title：Statistics in medicine

authors： Yu J,Yang L,Vexler A,Hutson AD

更新日期：2016-06-15 00:00:00

abstract：:We examine different methods to pool binary outcomes used both in parallel and cross-over trials. Odds ratio (OR) estimators obtained from joint conditional probabilities in cross-over trials, such as the Mantel-Haenszel and Peto methods, are compared to an OR estimator using marginal results of cross-over trials. Whe...

journal_title：Statistics in medicine

authors： Curtin F,Elbourne D,Altman DG

更新日期：2002-08-15 00:00:00

abstract：:We construct nonparametric regression estimators of a number of temporal functions in a multistate system based on a continuous univariate baseline covariate. These estimators include state occupation probabilities, state entry, exit, and waiting (sojourn) time distribution functions of a general progressive (e.g., ac...

journal_title：Statistics in medicine

authors： Mostajabi F,Datta S

更新日期：2013-07-30 00:00:00

abstract：:Phase II trials often test the null hypothesis H(0): p or=p(1), where p is the true unknown proportion responding to the new treatment, p(0) is the greatest response proportion which is deemed clinically ineffective, and p(1) is the smallest response proportion which is deemed clinically effe...

journal_title：Statistics in medicine

authors： Ayanlowo AO,Redden DT

更新日期：2007-03-30 00:00:00

abstract：:We consider evaluation and comparison of the diagnostic accuracy of biomarkers with continuous test outcomes, possibly correlated due to repeated measurements. We develop nonparametric group sequential testing procedures to evaluate and compare the area of biomarkers under their receiver operating characteristic curve...

journal_title：Statistics in medicine

authors： Liu A,Wu C,Schisterman EF

更新日期：2008-05-10 00:00:00

abstract：:Summarizing the information of many studies using a meta-analysis becomes more and more important, also in the field of diagnostic studies. The special challenge in meta-analysis of diagnostic accuracy studies is that in general sensitivity and specificity are co-primary endpoints. Across the studies both endpoints ar...

journal_title：Statistics in medicine

authors： Zapf A,Hoyer A,Kramer K,Kuss O

更新日期：2015-12-20 00:00:00

abstract：:We discuss some of the statistical approaches to the design and analysis of phase I clinical trials in cancer. An attempt is made to identify the issues, particular to this type of trial, that should be addressed by an appropriate methodology. A brief review of schemes currently in use is provided together with our vi...

journal_title：Statistics in medicine

authors： O'Quigley J,Chevret S

更新日期：1991-11-01 00:00:00

abstract：:We present a method to estimate the time-dependent vaccine efficacy from the cohort-specific vaccination coverage and from data on the vaccination status of cases and apply it to a measles epidemic in Germany which involved 529 cases, 88 of whom were vaccinated and 370 unvaccinated (for the remaining 71 cases the vacc...

journal_title：Statistics in medicine

authors： Eichner M,Diebner HH,Schubert C,Kreth HW,Dietz K

更新日期：2002-08-30 00:00:00

abstract：:Sexually transmitted infections (STIs) with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis are among the most common infectious diseases in the United States, disproportionately affecting young women. Because a significant portion of the infections present no symptoms, infection control relies...

journal_title：Statistics in medicine

authors： Li Z,Liu H,Tu W

更新日期：2015-09-10 00:00:00

abstract：:In this paper, we argue that causal effect models for realistic individualized treatment rules represent an attractive tool for analyzing sequentially randomized trials. Unlike a number of methods proposed previously, this approach does not rely on the assumption that intermediate outcomes are discrete or that models ...

journal_title：Statistics in medicine

authors： Bembom O,van der Laan MJ

更新日期：2008-08-30 00:00:00

abstract：:Blinded estimation of variance allows for changing the sample size without compromising the integrity of the trial. Some of the methods that estimate the variance in a blinded manner either make untenable assumptions or are only applicable to two-treatment trials. We propose a new method for continuous endpoints that ...

journal_title：Statistics in medicine

authors： Xing B,Ganju J

更新日期：2005-06-30 00:00:00

abstract：:In order for national statistical offices to maintain the trust of the public to collect data and publish statistics of importance to society and decision-making, it is imperative that respondents (persons or establishments) be guaranteed privacy and confidentiality in return for providing requested confidential data....

journal_title：Statistics in medicine

authors： Gonzalez JF Jr,Cox LH

更新日期：2005-02-28 00:00:00

abstract：:The use of data from multiple studies or centers for the validation of a clinical test or a multivariable prediction model allows researchers to investigate the test's/model's performance in multiple settings and populations. Recently, meta-analytic techniques have been proposed to summarize discrimination and calibra...

journal_title：Statistics in medicine

authors： Wynants L,Riley RD,Timmerman D,Van Calster B

更新日期：2018-05-30 00:00:00

abstract：:We consider the problem of identifying a subgroup of patients who may have an enhanced treatment effect in a randomized clinical trial, and it is desirable that the subgroup be defined by a limited number of covariates. For this problem, the development of a standard, pre-determined strategy may help to avoid the well...

journal_title：Statistics in medicine

authors： Foster JC,Taylor JM,Ruberg SJ

更新日期：2011-10-30 00:00:00

abstract：:A mixed effect model is proposed to jointly analyze multivariate longitudinal data with continuous, proportion, count, and binary responses. The association of the variables is modeled through the correlation of random effects. We use a quasi-likelihood type approximation for nonlinear variables and transform the prop...

journal_title：Statistics in medicine

authors： Li H,Zhang Y,Carroll RJ,Keadle SK,Sampson JN,Matthews CE

更新日期：2017-11-10 00:00:00

abstract：:A preference trial is a special form of cross-over trial where clinical conditions determine when patients change treatment, in a prescribed order. This can be modelled using a geometric distribution. The model can be simply fitted using standard logistic regression methodology. The procedure is applied to a trial stu...

journal_title：Statistics in medicine

authors： Lindsey JK,Jones B

更新日期：1996-02-28 00:00:00