Model diagnostics for censored regression via randomized survival probabilities.

abstract：:This paper reviews Bayesian strategies for monitoring clinical trial data. It focuses on a Bayesian stochastic curtailment method based on the predictive probability of observing a clinically significant outcome at the scheduled end of the study given the observed data. The proposed method is applied to derive efficac...

journal_title：Statistics in medicine

authors： Dmitrienko A,Wang MD

更新日期：2006-07-15 00:00:00

abstract：:Many models for clinical prediction (prognosis or diagnosis) are published in the medical literature every year but few such models find their way into clinical practice. The reason may be that since in most cases models have not been validated in independent data, they lack generality and/or credibility. In this pape...

journal_title：Statistics in medicine

authors： Royston P,Parmar MK,Sylvester R

更新日期：2004-03-30 00:00:00

abstract：:Missing values in the covariates are a widespread complication in the statistical inference of regression models. The maximum likelihood principle requires specification of the distribution of the covariates, at least in part. For categorical covariates, log-linear models can be used. Additionally, the missing at rand...

journal_title：Statistics in medicine

authors： Vach W,Blettner M

更新日期：1995-06-30 00:00:00

abstract：:Non-linear mixed-effects models (NLMEMs) are used to improve information gathering from longitudinal studies and are applied to treatment evaluation in disease-evolution studies, such as human immunodeficiency virus (HIV) infection. The estimation of parameters and the statistical tests are critical issues in NLMEMs s...

journal_title：Statistics in medicine

authors： Samson A,Lavielle M,Mentré F

更新日期：2007-11-30 00:00:00

abstract：:We suggest measures to quantify the degrees of necessity and of sufficiency of prognostic factors for dichotomous and for survival outcomes. A cause, represented by certain values of prognostic factors, is considered necessary for an event if, without the cause, the event cannot develop. It is considered sufficient fo...

journal_title：Statistics in medicine

authors： Gleiss A,Schemper M

更新日期：2019-10-15 00:00:00

abstract：:Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and t...

journal_title：Statistics in medicine

authors： Capuano AW,Dawson JD

更新日期：2013-06-15 00:00:00

abstract：:Writing the variance of the Mantel-Haenszel estimator under the null of homogeneity and inverting the corresponding test, we arrive at an improved confidence interval for the common risk difference in stratified 2 × 2 tables. This interval outperforms a variety of other intervals currently recommended in the literatur...

journal_title：Statistics in medicine

authors： Klingenberg B

更新日期：2014-07-30 00:00:00

abstract：:The development of drugs and biologicals whose mechanisms of action may extend beyond their target indications has led to a need to identify unexpected potential toxicities promptly even while blinded clinical trials are under way. One component of recently issued FDA rules regarding safety reporting requirements rais...

journal_title：Statistics in medicine

authors： Gould AL,Wang WB

更新日期：2017-01-15 00:00:00

abstract：:Despite our best efforts, missing outcomes are common in randomized controlled clinical trials. The National Research Council's Committee on National Statistics panel report titled The Prevention and Treatment of Missing Data in Clinical Trials noted that further research is required to assess the impact of missing da...

journal_title：Statistics in medicine

authors： Cook T,Zea R

更新日期：2020-01-30 00:00:00

abstract：:The additional time to complete a three-period two-treatment (3P2T) cross-over trial may cause a greater number of patient dropouts than with a two-period trial. This paper develops maximum likelihood (ML), single imputation and multiple imputation missing data analysis methods for the 3P2T cross-over designs. We use ...

journal_title：Statistics in medicine

authors： Richardson BA,Flack VF

更新日期：1996-01-30 00:00:00

abstract：:In many chronic diseases, therapy aims to prevent or reduce the frequency of episodes of a disease manifestation, for example cardiac ischaemic episodes or epileptic seizures. Entry criteria for clinical trials typically include a minimum number of episodes within a baseline period, and regression to the mean should b...

journal_title：Statistics in medicine

authors： McMahon RP,Proschan M,Geller NL,Stone PH,Sopko G

更新日期：1994-04-30 00:00:00

abstract：:In this commentary, we revisit Sir Austin Bradford Hill's seminal Alfred Watson Memorial Lecture in 1962 through the eyes of two practicing biostatisticians of the current era. We summarize some eternal takeaway messages from Hill's lecture regarding observations and experiments translated through the modern lexicon o...

journal_title：Statistics in medicine

authors： Dempsey W,Mukherjee B

更新日期：2021-01-15 00:00:00

abstract：:In England and Wales, a large-scale multiple statistical surveillance system for infectious disease outbreaks has been in operation for nearly two decades. This system uses a robust quasi-Poisson regression algorithm to identify abberrances in weekly counts of isolates reported to the Health Protection Agency. In this...

journal_title：Statistics in medicine

authors： Noufaily A,Enki DG,Farrington P,Garthwaite P,Andrews N,Charlett A

更新日期：2013-03-30 00:00:00

abstract：:Correlation analysis is widely used in biomedical and psychosocial research for assessing rater reliability, precision of diagnosis and accuracy of proxy outcomes. The popularity of longitudinal study designs has propelled the proliferation in recent years of new methods for longitudinal and other multi-level clustere...

journal_title：Statistics in medicine

authors： Tu XM,Feng C,Kowalski J,Tang W,Wang H,Wan C,Ma Y

更新日期：2007-09-30 00:00:00

abstract：:A problem occurring in chronic disease modeling is the estimation of transition probabilities of moving from one state of a categorical risk factor to another. Transitions could be obtained from a cohort study, but often such data may not be available. However, under the assumption that transitions remain stable over ...

journal_title：Statistics in medicine

authors： Kassteele Jv,Hoogenveen RT,Engelfriet PM,Baal PH,Boshuizen HC

更新日期：2012-03-15 00:00:00

abstract：:Recurrent event data are commonly encountered in health-related longitudinal studies. In this paper time-to-events models for recurrent event data are studied with non-informative and informative censorings. In statistical literature, the risk set methods have been confirmed to serve as an appropriate and efficient ap...

journal_title：Statistics in medicine

authors： Wang MC,Chiang CT

更新日期：2002-02-15 00:00:00

abstract：:Non-tumor cell-based model systems have recently gained interest in pharmacogenetic research as a hypothesis generating tool. The hypotheses generated from these model systems can be followed up in functional studies, or tested in individuals taking the same investigational agents. The current cellular phenotypes (e.g...

journal_title：Statistics in medicine

authors： Fridley BL,Jenkins G,Schaid DJ,Wang L

更新日期：2009-09-20 00:00:00

abstract：:In a recent Statistics in Medicine paper, Warn, Thompson and Spiegelhalter (WTS) made a comparison between the Bayesian approach to the meta-analysis of binary outcomes and a popular Classical approach that uses summary (two-stage) techniques. They included approximate summary (two-stage) Bayesian techniques in their ...

journal_title：Statistics in medicine

authors： O'Rourke K,Altman DG

更新日期：2005-09-15 00:00:00

abstract：:The use of the continual reassessment method (CRM) and other model-based approaches to design Phase I clinical trials has increased owing to the ability of the CRM to identify the maximum tolerated dose better than the 3 + 3 method. However, the CRM can be sensitive to the variance selected for the prior distribution ...

journal_title：Statistics in medicine

authors： Zhang J,Braun TM,Taylor JM

更新日期：2013-06-15 00:00:00

abstract：:In medical research, risk difference (RD) and number needed to treat (NNT) measures for survival times have been mainly proposed without consideration of covariates. In this paper, we develop adjusted RD and NNT measures for use in observational studies with survival time outcomes within the framework of the Cox propo...

journal_title：Statistics in medicine

authors： Laubender RP,Bender R

更新日期：2010-03-30 00:00:00

abstract：:This paper discusses design considerations and the role of randomization-based inference in randomized community intervention trials. We stress that longitudinal follow-up of cohorts within communities often yields useful information on the effects of intervention on individuals, whereas cross-sectional surveys can us...

journal_title：Statistics in medicine

authors： Gail MH,Mark SD,Carroll RJ,Green SB,Pee D

更新日期：1996-06-15 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：:Biomarkers, increasingly used in biomedical studies for the diagnosis and prognosis of acute and chronic diseases, provide insight into the effectiveness of treatments and potential pathways that can be used to guide future treatment targets. The measurement of these markers is often limited by the sensitivity of the ...

journal_title：Statistics in medicine

authors： Lee M,Kong L,Weissfeld L

更新日期：2012-07-30 00:00:00

abstract：:In a long-running longitudinal study using complex machinery to obtain measurements, it is sometimes necessary to replace the machine. This can result in lack of continuity in the measurements that can overwhelm any treatment effect or time trend. We propose a Bayesian procedure implemented using Markov chain Monte Ca...

journal_title：Statistics in medicine

authors： Ambrosius WT,Hui SL

更新日期：2004-09-30 00:00:00

abstract：:We examine the common clinical belief that there is an interaction between epilepsy type and the two standard anti-epileptic drugs, valproate and carbamazepine, using data from several randomized clinical trials. Epilepsy type is not always easy to define, and three possible reclassifications are investigated to see w...

journal_title：Statistics in medicine

authors： Williamson PR,Clough HE,Hutton JL,Marson AG,Chadwick DW

更新日期：2002-09-30 00:00:00

abstract：:The 'at least as good as' criterion, introduced by Laster and Johnson for a continuous response variate, is developed here for applications with dichotomous data. This approach is adaptive in nature, as the margin of non-inferiority is not taken as a fixed difference; it varies as a function of the positive control re...

journal_title：Statistics in medicine

authors： Laster LL,Johnson MF,Kotler ML

更新日期：2006-04-15 00:00:00

abstract：:Box-Cox transformation is investigated for regression models for left-censored data. Examples are provided using coronary calcification data from the Multi-Ethnic Study of Atherosclerosis and pharmacokinetic data of a nicotine nasal spray. ...

journal_title：Statistics in medicine

authors： Han C,Kronmal R

更新日期：2004-12-15 00:00:00

abstract：:The Cardiac Arrythmia Suppression Trial was stopped much earlier than planned. Statistical considerations played a very important role in the decision. Flexible group sequential testing was developed for the trial by implementing a Lan and DeMets procedure with use of the permutation test. We compute P-values from the...

journal_title：Statistics in medicine

authors： Pawitan Y,Hallstrom A

更新日期：1990-09-01 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：:Patient non-compliance and drop-out can bias analyses of clinical trial data. I describe a parametric model for treatment cross-over and drop-out and demonstrate how the concept of ignorability, originally defined for incomplete-data problems, can elucidate sources of bias in clinical trials. I discuss some implicatio...

journal_title：Statistics in medicine

authors： Heitjan DF

更新日期：1999-09-15 00:00:00