Monitoring potential adverse event rate differences using data from blinded trials: the canary in the coal mine.

abstract：:Parameters for latent transition analysis (LTA) are easily estimated by maximum likelihood (ML) or Bayesian method via Markov chain Monte Carlo (MCMC). However, unusual features in the likelihood can cause difficulties in ML and Bayesian inference and estimation, especially with small samples. In this study we explore...

journal_title：Statistics in medicine

authors： Chung H,Lanza ST,Loken E

更新日期：2008-05-20 00:00:00

abstract：:The general linear mixed model provides a useful approach for analysing a wide variety of data structures which practising statisticians often encounter. Two such data structures which can be problematic to analyse are unbalanced repeated measures data and longitudinal data. Owing to recent advances in methods and sof...

journal_title：Statistics in medicine

authors： Cnaan A,Laird NM,Slasor P

更新日期：1997-10-30 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：:In lifetime data, like cancer studies, there may be long term survivors, which lead to heavy censoring at the end of the follow-up period. Since a standard survival model is not appropriate to handle these data, a cure model is needed. In the literature, covariate hypothesis tests for cure models are limited to parame...

journal_title：Statistics in medicine

authors： López-Cheda A,Jácome MA,Van Keilegom I,Cao R

更新日期：2020-07-30 00:00:00

abstract：:In the pharmaceutical industry, some tests for quality assurance before, during and after the manufacture of a drug product involve a two-stage sampling technique. We propose statistical testing procedures in a two-stage sampling problem with large within-class sample sizes. We also derive a two-stage sampling plan by...

journal_title：Statistics in medicine

authors： Shao J,Chow SC

更新日期：1993-11-15 00:00:00

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：:Patient compliance (adherence) with prescribed medication is often erratic, while clinical outcomes are causally linked to actual, rather than nominal medication dosage. We propose here a hierarchical Markov model for patient compliance. At the first stage, conditional upon individual random effects and a set of indiv...

journal_title：Statistics in medicine

authors： Girard P,Blaschke TF,Kastrissios H,Sheiner LB

更新日期：1998-10-30 00:00:00

abstract：:Cost data that arise in the evaluation of health care technologies usually exhibit highly skew, heavy-tailed and, possibly, multi-modal distributions. Distribution-free methods for analysing these data, such as the bootstrap, or those based on the asymptotic normality of sample means, may often lead to inefficient or ...

journal_title：Statistics in medicine

authors： Conigliani C,Tancredi A

更新日期：2005-10-30 00:00:00

abstract：:A popular method for analysing repeated-measures data is generalized estimating equations (GEE). When response data are missing at random (MAR), two modifications of GEE use inverse-probability weighting and imputation. The weighted GEE (WGEE) method involves weighting observations by their inverse probability of bein...

journal_title：Statistics in medicine

authors： Seaman S,Copas A

更新日期：2009-03-15 00:00:00

abstract：:Various aspects of portfolio management and project prioritization within the pharmaceutical industry are examined. It is shown that the cost and probability architecture of a project is a crucial aspect of its value. An appropriate simple tool for ranking projects is the Pearson index. Various difficulties are consid...

journal_title：Statistics in medicine

authors： Senn S

更新日期：1996-12-30 00:00:00

abstract：:Lung function tests are used both clinically, in assessing disease, and epidemiologically, in identifying those factors which influence the growth and aging process of the lungs. The user must beware of several common pitfalls in the use of these tests, however. First, the commonly used tests of lung function can only...

journal_title：Statistics in medicine

authors： Buist AS,Vollmer WM

更新日期：1988-01-01 00:00:00

abstract：:This paper describes compliance with the completion of a quality of life questionnaire in the Breast Cancer Prevention Trial, a large multi-centre randomized trial that is studying the efficacy of Tamoxifen in preventing breast cancer. In the first 4875 women enrolled in the control arm of the study, there was a very ...

journal_title：Statistics in medicine

authors： Ganz PA,Day R,Costantino J

更新日期：1998-03-15 00:00:00

abstract：:In the recent two decades, data mining methods for signal detection have been developed for drug safety surveillance, using large post-market safety data. Several of these methods assume that the number of reports for each drug-adverse event combination is a Poisson random variable with mean proportional to the unknow...

journal_title：Statistics in medicine

authors： Hu N,Huang L,Tiwari RC

更新日期：2015-08-30 00:00:00

abstract：:Both the variation of positive responses (negative responses) among individuals and the internal correlation among responses for the same individual affect the precision of the estimate of sensitivity (specificity). To estimate the sensitivity (specificity) of a medical diagnostic test, this paper proposes a Bayesian ...

journal_title：Statistics in medicine

authors： Lui KJ

更新日期：1989-10-01 00:00:00

abstract：:The application of Bayesian hierarchical models to measure spatial effects in time to event data has not been widely reported. This case study aims to estimate the effect of area of residence on waiting times to coronary artery bypass graft (CABG) and to assess the role of important individual specific covariates (age...

journal_title：Statistics in medicine

authors： Crook AM,Knorr-Held L,Hemingway H

更新日期：2003-09-30 00:00:00

abstract：:A new, intuitive method has recently been proposed to explore treatment-covariate interactions in survival data arising from two treatment arms of a clinical trial. The method is based on constructing overlapping subpopulations of patients with respect to one (or more) covariates of interest and in observing the patte...

journal_title：Statistics in medicine

authors： Bonetti M,Zahrieh D,Cole BF,Gelber RD

更新日期：2009-04-15 00:00:00

abstract：:In this paper we describe Bonferroni-based multiple testing procedures (MTPs) as strategies to split and recycle test mass. Here, 'test mass' refers to (parts of) the nominal level alpha at which the family-wise error rate is controlled. Briefly, test mass is split between different null hypotheses, and whenever a nul...

journal_title：Statistics in medicine

authors： Burman CF,Sonesson C,Guilbaud O

更新日期：2009-02-28 00:00:00

abstract：:In US states with small subpopulations, the observed mortality rates are often zero, particularly among young ages. Because in life tables, death rates are reported mostly on a log scale, zero mortality rates are problematic. To overcome the observed zero death rates problem, appropriate probability models are used. U...

journal_title：Statistics in medicine

authors： Voulgaraki A,Wei R,Kedem B

更新日期：2015-05-20 00:00:00

abstract：:This paper investigates the impact on area life tables of the specification of unobserved frailty. Frailty specification may affect both the regression effects of area and individual level covariates, and lead to changes in the value of summary mortality parameters, such as life expectancy. The paper also investigates...

journal_title：Statistics in medicine

authors： Congdon P

更新日期：1995-09-15 00:00:00

abstract：:Testing involving the intra-class kappa coefficient is commonly performed in order to assess agreement involving categorical ratings. A number of procedures have been proposed, which make use of the limiting null distribution as the sample size goes to infinity in order to compute the observed significance. As with ma...

journal_title：Statistics in medicine

authors： Wilding GE,Consiglio JD,Shan G

更新日期：2014-07-30 00:00:00

abstract：:Elevated plasma levels of apolipoproteins A1 (apoA1) and B (apoB) are important protective factors and risk factors, respectively, for atherosclerosis and coronary heart disease. It is well known that both apoA1 and apoB reveal strong familial aggregation. Our goal was to investigate whether exogenous variables influe...

journal_title：Statistics in medicine

authors： Ziegler A,Kastner C,Brunner D,Blettner M

更新日期：2000-12-30 00:00:00

abstract：:Prevalent sampling is frequently a convenient and economical sampling technique for the collection of time-to-event data and thus is commonly used in studies of the natural history of a disease. However, it is biased by design because it tends to recruit individuals with longer survival times. This paper considers est...

journal_title：Statistics in medicine

authors： Li S

更新日期：2017-04-15 00:00:00

abstract：:Identification of treatment selection biomarkers has become very important in cancer drug development. Adaptive enrichment designs have been developed for situations where a unique treatment selection biomarker is not apparent based on the mechanism of action of the drug. With such designs, the eligibility rules may b...

journal_title：Statistics in medicine

authors： Simon R,Simon N

更新日期：2017-11-20 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

abstract：:Many complex diseases are known to be affected by the interactions between genetic variants and environmental exposures beyond the main genetic and environmental effects. Study of gene-environment (G×E) interactions is important for elucidating the disease etiology. Existing Bayesian methods for G×E interaction studie...

journal_title：Statistics in medicine

authors： Ren J,Zhou F,Li X,Chen Q,Zhang H,Ma S,Jiang Y,Wu C

更新日期：2020-02-28 00:00:00

abstract：:Motivated by a previously published study of HIV treatment, we simulated data subject to time-varying confounding affected by prior treatment to examine some finite-sample properties of marginal structural Cox proportional hazards models. We compared (a) unadjusted, (b) regression-adjusted, (c) unstabilized, and (d) s...

journal_title：Statistics in medicine

authors： Westreich D,Cole SR,Schisterman EF,Platt RW

更新日期：2012-08-30 00:00:00

abstract：:Important differences between explanatory and pragmatic studies were originally argued by Schwartz and Lellouch. Three important differences between the two types of study involve study control, study violators and inclusion criteria. It was originally argued that explanatory studies are highly controlled, and pragmat...

journal_title：Statistics in medicine

authors： McMahon AD

更新日期：2002-05-30 00:00:00

abstract：:A survey is conducted at w of K selection units or lists, e.g. health care institutions or weeks in a year, to estimate N, the total number of individuals with particular characteristics. Our estimator utilizes two items determined for each survey participant: the number, u, among the w lists in S and the number, j, a...

journal_title：Statistics in medicine

authors： Laska EM,Meisner M,Wanderling J

更新日期：2009-07-30 00:00:00

abstract：:Mediation analyses can help us to understand the biological mechanism in which an exposure or treatment affects an outcome. Single mediator analyses have been used in various applications, but may not be appropriate for analyzing intricate mechanisms involving multiple mediators that affect each other. Thus, in this a...

journal_title：Statistics in medicine

authors： Lai EY,Shih S,Huang YT,Wang S

更新日期：2020-05-15 00:00:00

abstract：:Clinical studies that involve the recording of two or more distinct and well-defined events on each subject give rise to multiple event data. Treatment comparisons are usually reported in univariate analyses of time to first event or number of events observed. However, this approach may not uncover the 'full story' of...

journal_title：Statistics in medicine

authors： Barai U,Teoh N

更新日期：1997-04-30 00:00:00