Exact equivalence test for risk ratio and its sample size determination under inverse sampling.

abstract：:We investigate a binary partitioning algorithm in the case of a continuous repeated measures outcome. The procedure is based on the use of the likelihood ratio statistic to evaluate the performance of individual splits. The procedure partitions a set of longitudinal data into two mutually exclusive groups based on an ...

journal_title：Statistics in medicine

authors： Abdolell M,LeBlanc M,Stephens D,Harrison RV

更新日期：2002-11-30 00:00:00

abstract：:Much has been published on various aspects of data analysis and reporting from clinical trials within the biopharmaceutical environment. This ranges from regulatory guidelines on the format and content of registration dossiers to recommendations on data presentation and the statistical methodologies that are appropria...

journal_title：Statistics in medicine

authors： Huster WJ,Enas GG

更新日期：1998-08-15 00:00:00

abstract：:A three-component, competing-risk mortality model, developed for animal survival data, fits human life table data for all ages over a range of mean life spans from 16 to 74 years. The competing risks are a novel exponentially-decreasing hazard, dominant during immaturity; a constant hazard, dominant during adulthood; ...

journal_title：Statistics in medicine

authors： Siler W

更新日期：1983-07-01 00:00:00

abstract：:Pearson's chi-squared, the likelihood-ratio, and Fisher-Freeman-Halton's test statistics are often used to test the association of unordered r x c tables. Asymptotical, exact conditional, or exact conditional with mid-p adjustment methods are commonly used to compute the p-value. We have compared test power and signif...

journal_title：Statistics in medicine

authors： Lydersen S,Pradhan V,Senchaudhuri P,Laake P

更新日期：2007-10-15 00:00:00

abstract：:Predicting an individual's risk of experiencing a future clinical outcome is a statistical task with important consequences for both practicing clinicians and public health experts. Modern observational databases such as electronic health records provide an alternative to the longitudinal cohort studies traditionally ...

journal_title：Statistics in medicine

authors： Wolfson J,Bandyopadhyay S,Elidrisi M,Vazquez-Benitez G,Vock DM,Musgrove D,Adomavicius G,Johnson PE,O'Connor PJ

更新日期：2015-09-20 00:00:00

abstract：:In this paper, we consider pooling schemes in which samples are to be tested in two-stages. We show that when batch size is limited as well as pool size, selection schemes tend to be more efficient and flexible. Formulae for the efficiencies of square arrays in all dimensions and for all selection schemes are given in...

journal_title：Statistics in medicine

authors： Sudbury A

更新日期：2010-09-20 00:00:00

abstract：:We extend the shared frailty model of recurrent events and a dependent terminal event to allow for a nonparametric covariate function. We include a Gaussian random effect (frailty) in the intensity functions of both the recurrent and terminal events to capture correlation between the two processes. We employ the penal...

journal_title：Statistics in medicine

authors： Zhangsheng Y,Liu L

更新日期：2011-09-30 00:00:00

abstract：:Individuals may vary in their responses to treatment, and identification of subgroups differentially affected by a treatment is an important issue in medical research. The risk of misleading subgroup analyses has become well known, and some exploratory analyses can be helpful in clarifying how covariates potentially i...

journal_title：Statistics in medicine

authors： Kim HJ,Lu B,Nehus EJ,Kim MO

更新日期：2019-02-10 00:00:00

abstract：:Standard approaches to analysis of randomized controlled trials (RCTs) using Markov models make it difficult to generalize treatment effects to new patient groups and synthesize evidence across trials. This paper demonstrates how pair-wise and mixed treatment comparison meta-analysis can be applied to event history da...

journal_title：Statistics in medicine

authors： Price MJ,Welton NJ,Ades AE

更新日期：2011-01-30 00:00:00

abstract：:We propose a new, less costly, design to test the equivalence of digital versus analogue mammography in terms of sensitivity and specificity. Because breast cancer is a rare event among asymptomatic women, the sample size for testing equivalence of sensitivity is larger than that for testing equivalence of specificity...

journal_title：Statistics in medicine

authors： Baker SG,Connor RJ,Kessler LG

更新日期：1998-10-15 00:00:00

abstract：:Correlation is always a concern in the analysis of clustered data. One area of interest is to develop a general correlation modelling approach for high dimensional data with unbalanced hierarchical and heterogeneous data structures, e.g. multilevel data. Commonly used correlation structures might have limitation for s...

journal_title：Statistics in medicine

authors： Chao EC

更新日期：2006-07-30 00:00:00

abstract：:We propose a joint modeling approach to investigating the observed and latent risk factors of mixed types of outcomes. The proposed model comprises three parts. The first part is an exploratory factor analysis model that summarizes latent factors through multiple observed variables. The second part is a proportional h...

journal_title：Statistics in medicine

authors： Pan D,Wei Y,Song X

更新日期：2020-12-09 00:00:00

abstract：:Missing data arise in crossover trials, as they do in any form of clinical trial. Several papers have addressed the problems that missing data create, although almost all of these assume that the probability that a planned observation is missing does not depend on the value that would have been observed; that is, the ...

journal_title：Statistics in medicine

authors： Ho WK,Matthews JN,Henderson R,Farewell D,Rodgers LR

更新日期：2012-07-20 00:00:00

abstract：:Among many other uses, positron emission tomography (PET) can be used in studies to estimate the density of a neuroreceptor at each location throughout the brain by measuring the concentration of a radiotracer over time and modeling its kinetics. There are a variety of kinetic models in common usage and these typicall...

journal_title：Statistics in medicine

authors： Chang C,Ogden RT

更新日期：2009-03-15 00:00:00

abstract：:Multilevel and longitudinal studies are frequently subject to missing data. For example, biomarker studies for oral cancer may involve multiple assays for each participant. Assays may fail, resulting in missing data values that can be assumed to be missing completely at random. Catellier and Muller proposed a data ana...

journal_title：Statistics in medicine

authors： Ringham BM,Kreidler SM,Muller KE,Glueck DH

更新日期：2016-07-30 00:00:00

abstract：:Results from an analysis of traffic accidents from a study of the police records of four police stations in the Bangkok metropolis are presented. The main emphasis in this study was put on the development of a measure for traffic accident density. The traffic flow was estimated at the various study locations by traine...

journal_title：Statistics in medicine

authors： Ayuthya RS,Böhning D

更新日期：1995-11-15 00:00:00

abstract：:Korn and Whittemore have presented methods for analyzing longitudinal data where the number of observations per individual is large relative to the number of variables considered for each subject. However, this is often not the case in epidemiologic studies, since one usually collects data at relatively few time point...

journal_title：Statistics in medicine

authors： Rosner B,Muñoz A,Tager I,Speizer F,Weiss S

更新日期：1985-10-01 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：:In applications such as medical statistics and genetics, we encounter situations where a large number of highly correlated predictors explain a response. For example, the response may be a disease indicator and the predictors may be treatment indicators or single nucleotide polymorphisms (SNPs). Constructing a good pr...

journal_title：Statistics in medicine

authors： Sperrin M,Jaki T

更新日期：2010-10-30 00:00:00

abstract：:Methodology for the meta-analysis of individual patient data with survival end-points is proposed. Motivated by questions about the reliance on hazard ratios as summary measures of treatment effects, a parametric approach is considered and percentile ratios are introduced as an alternative to hazard ratios. The genera...

journal_title：Statistics in medicine

authors： Siannis F,Barrett JK,Farewell VT,Tierney JF

更新日期：2010-12-20 00:00:00

abstract：:Between-community variance or community-by-time variance is one of the key factors driving the cost of conducting group randomized trials, which are often very expensive. We investigated empirically whether between-community variance could be reduced by controlling individual- and/or community-level covariates and ide...

journal_title：Statistics in medicine

authors： Feng Z,Diehr P,Yasui Y,Evans B,Beresford S,Koepsell TD

更新日期：1999-03-15 00:00:00

abstract：:Many observational studies adopt what we call retrospective convenience sampling (RCS). With the sample size in each arm prespecified, RCS randomly selects subjects from the treatment-inclined subpopulation into the treatment arm and those from the control-inclined into the control arm. Samples in each arm are represe...

journal_title：Statistics in medicine

authors： Hu Z,Qin J

更新日期：2018-05-20 00:00:00

abstract：:Typical analyses of lifetime data treat the time to death or failure as the response variable and use a variety of modelling strategies such as proportional hazards or fully parametric, to investigate the relationship between the response and covariates. In certain circumstances it may be more natural to view the dist...

journal_title：Statistics in medicine

authors： Ghahramani M,Dean CB,Spinelli JJ

更新日期：2001-07-15 00:00:00

abstract：:In clinical research, investigators are interested in inferring the average causal effect of a treatment. However, the causal parameter that can be used to derive the average causal effect is not well defined for ordinal outcomes. Although some definitions have been proposed, they are limited in that they are not iden...

journal_title：Statistics in medicine

authors： Chiba Y

更新日期：2017-11-10 00:00:00

abstract：:Inference for randomized clinical trials is generally based on the assumption that outcomes are independently and identically distributed under the null hypothesis. In some trials, particularly in infectious disease, outcomes may be correlated. This may be known in advance (e.g. allowing randomization of family member...

journal_title：Statistics in medicine

authors： Proschan M,Follmann D

更新日期：2008-03-15 00:00:00

abstract：:A significant source of missing data in longitudinal epidemiological studies on elderly individuals is death. Subjects in large scale community-based longitudinal dementia studies are usually evaluated for disease status in study waves, not under continuous surveillance as in traditional cohort studies. Therefore, for...

journal_title：Statistics in medicine

authors： Harezlak J,Gao S,Hui SL

更新日期：2003-05-15 00:00:00

abstract：:Although the frequentist paradigm has been the predominant approach to clinical trial design since the 1940s, it has several notable limitations. Advancements in computational algorithms and computer hardware have greatly enhanced the alternative Bayesian paradigm. Compared with its frequentist counterpart, the Bayesi...

journal_title：Statistics in medicine

authors： Lee JJ,Chu CT

更新日期：2012-11-10 00:00:00

abstract：:Exploring the possible reasons for heterogeneity between studies is an important aspect of conducting a meta-analysis. This paper compares a number of methods which can be used to investigate whether a particular covariate, with a value defined for each study in the meta-analysis, explains any heterogeneity. The main ...

journal_title：Statistics in medicine

authors： Thompson SG,Sharp SJ

更新日期：1999-10-30 00:00:00

abstract：:In longitudinal studies with incomplete data, where the number of time points can become numerous, it is often advantageous to model the covariance matrix. We describe several covariance models (for example, mixed models, compound symmetry, AR(1)-type models, and combination models) that offer parsimonious alternative...

journal_title：Statistics in medicine

authors： Grady JJ,Helms RW

更新日期：1995-07-15 00:00:00

abstract：:A Non-Parametric Maximum Likelihood approach to the estimation of relative risks in the context of disease mapping is discussed and a NPML approximation to conditional autoregressive models is proposed. NPML estimates have been compared to other proposed solutions (Maximum Likelihood via Monte Carlo Scoring, Hierarchi...

journal_title：Statistics in medicine

authors： Biggeri A,Marchi M,Lagazio C,Martuzzi M,Böhning D

更新日期：2000-09-15 00:00:00