A random forest approach for competing risks based on pseudo-values.

abstract：:Standard methods for analysing survival data or case-control data normally concern factors affecting a subject as a whole. However, in a study of a condition that might develop in one or both of a pair of bodily organs information on response and on covariates may be available for each separately. This information can...

journal_title：Statistics in medicine

authors： Whitehead J,Dorse C

更新日期：1988-05-01 00:00:00

abstract：:A trial of Duchenne muscular dystrophy involved tracking boys of all ages through a one-year baseline period, followed by a one-year trial of leucine versus placebo treatment. In this paper we develop a model for a total-muscle-strength score that uses the data of the extended baseline period in the evaluation of the ...

journal_title：Statistics in medicine

authors： Madsen KS,Miller JP,Province MA

更新日期：1986-05-01 00:00:00

abstract：:Clinical trials utilizing predictive biomarkers have become a research focus in personalized medicine. We investigate the effects of biomarker misclassification on the design and analysis of stratified biomarker clinical trials. For a variety of inference problems including marker-treatment interaction in particular, ...

journal_title：Statistics in medicine

authors： Liu C,Liu A,Hu J,Yuan V,Halabi S

更新日期：2014-08-15 00:00:00

abstract：:The coefficient of individual equivalence is a permutation-based measure of agreement between two observers making replicated readings on each subject. It compares the observed disagreement between the observers to the expected disagreement under individual equivalence. Individual equivalence of observers requires tha...

journal_title：Statistics in medicine

authors： Pan Y,Haber M,Gao J,Barnhart HX

更新日期：2012-09-10 00:00:00

abstract：:We applied a two-stage random effects model to pulmonary function data from 31 sarcoidosis patients to illustrate its usefulness in analysing unbalanced longitudinal data. For the first stage, repeated measurements of percentage of predicted forced vital capacity (FVC%) from an individual were modelled as a function o...

journal_title：Statistics in medicine

authors： Vacek PM,Mickey RM,Bell DY

更新日期：1989-02-01 00:00:00

abstract：:Randomized clinical trial designs commonly include one or more planned interim analyses. At these times an external monitoring committee reviews the accumulated data and determines whether it is scientifically and ethically appropriate for the study to continue. With failure-time endpoints, it is common to schedule an...

journal_title：Statistics in medicine

authors： Bagiella E,Heitjan DF

更新日期：2001-07-30 00:00:00

abstract：:In the pharmaceutical industry, an assay method is considered validated if the accuracy and precision for an assay meet some acceptable limits. This paper discusses the assessment of assay precision in terms of the estimation of total variability of an assay from a one-way random effects model which is often considere...

journal_title：Statistics in medicine

authors： Chow SC,Tse SK

更新日期：1991-10-01 00:00:00

abstract：:The Rvachev-Baroyan-Longini model is a space-time predictive model of the spread of influenza epidemics. It has been applied to 128 cities of the USSR, and more recently, to forecasting the spread of the pandemic of 1968-1969 throughout 52 large cities. It is a deterministic, mass-action, space and time continuous mod...

journal_title：Statistics in medicine

authors： Flahault A,Letrait S,Blin P,Hazout S,Ménarés J,Valleron AJ

更新日期：1988-11-01 00:00:00

abstract：:Austin Bradford Hill was once a friend to The Lancet, but, as occasionally happens, friends fall out. The great legacy of his association with the journal, however, was Principles of Medical Statistics. As each edition was succeeded by another--the first in 1937, the last in 1991--he seemed to shift his view about the...

journal_title：Statistics in medicine

authors： Horton R

更新日期：2000-12-15 00:00:00

abstract：:This paper gives a standard error for Cohen's Kappa, conditional on the margins of the observed r x r table. An explicit formula is given for the 2 x 2 table, and a procedure for the more general situation. A parsimonious log-linear model is suggested for the general case and an approximate confidence interval for kap...

journal_title：Statistics in medicine

authors： Garner JB

更新日期：1991-05-01 00:00:00

abstract：:The standard analysis of clinical trials stratified by centre is to include centres as fixed effects, but if many centres contribute small numbers of patients, this approach results in a loss of power. Assuming no treatment by centre interaction, we used simulation to examine power and coverage of confidence intervals...

journal_title：Statistics in medicine

authors： Pickering RM,Weatherall M

更新日期：2007-12-30 00:00:00

abstract：:Members of a cohort of workers in chemical industry (the so-called Boehringer cohort) exposed to 2, 3, 7, 8-tetrachlorodibenzo-para-dioxin (TCDD) from 1950 to 1984 were subject in the years 1985-1986 and 1992-1994 to an extensive biomonitoring programme on the TCDD levels of the individual workers. For establishing a ...

journal_title：Statistics in medicine

authors： Heinzl H,Mittlböck M,Edler L

更新日期：2008-05-30 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：:Biomarkers that predict the efficacy of treatment can potentially improve clinical outcomes and decrease medical costs by allowing treatment to be provided only to those most likely to benefit. We consider the design of a randomized clinical trial in which one objective is to evaluate a treatment selection marker. The...

journal_title：Statistics in medicine

authors： Janes H,Brown MD,Pepe MS

更新日期：2015-11-30 00:00:00

abstract：:A relationship between baseline risk and treatment effect is increasingly investigated as a possible explanation of between-study heterogeneity in clinical trial meta-analysis. An approach that is still often applied in the medical literature is to plot the estimated treatment effects against the estimated measures of...

journal_title：Statistics in medicine

authors： Arends LR,Hoes AW,Lubsen J,Grobbee DE,Stijnen T

更新日期：2000-12-30 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：:In any field in which decisions are subject to measurements, interchangeability between the methods used to obtain these measurements is essential. To consider methods as interchangeable, a certain degree of agreement is needed between the measurements they provide. The concordance correlation coefficient is an index ...

journal_title：Statistics in medicine

authors： Carrasco JL,Jover L

更新日期：2005-12-30 00:00:00

abstract：:The FDA Guidance, while highly appropriate for industry sponsored trials, need not be imposed on publicly (e.g. NIH) financed clinical trials. While the potential for conflicts of interest exist in the latter, they are in general manageable and pose an acceptable low risk of threatening the integrity of a study. Howev...

journal_title：Statistics in medicine

authors： Lachin JM

更新日期：2004-05-30 00:00:00

abstract：:Multivariate finite mixture models have been applied to the identification of dietary patterns. These models are known to have many parameters, and consequently large samples are usually required. We present a special case of a multivariate mixture model that reduces the number of parameters to be estimated and seems ...

journal_title：Statistics in medicine

authors： Rita Gaio A,Costa JP,Santos AC,Ramos E,Lopes C

更新日期：2012-08-30 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：: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：:Often multiple outcomes are of interest in each study identified by a systematic review, and in this situation a separate univariate meta-analysis is usually applied to synthesize the evidence for each outcome independently; an alternative approach is a single multivariate meta-analysis model that utilizes any correla...

journal_title：Statistics in medicine

authors： Riley RD,Abrams KR,Lambert PC,Sutton AJ,Thompson JR

更新日期：2007-01-15 00:00:00

abstract：:In cancer clinical trials, patients often experience a recurrence of disease prior to the outcome of interest, overall survival. Additionally, for many cancers, there is a cured fraction of the population who will never experience a recurrence. There is often interest in how different covariates affect the probability...

journal_title：Statistics in medicine

authors： Conlon AS,Taylor JM,Sargent DJ

更新日期：2014-05-10 00:00:00

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：:It has been increasingly common to analyze simultaneously repeated measures and time to failure data. In this paper we propose a joint model when the repeated measures are semi-continuous, characterized by the presence of a large portion of zero values, as well as right skewness of non zero (positive) values. Examples...

journal_title：Statistics in medicine

authors： Liu L

更新日期：2009-03-15 00:00:00

abstract：:The goal of phase I cancer trials is to determine the highest dose of a treatment regimen with an acceptable toxicity rate. Traditional designs for phase I trials, such as the Continual Reassessment Method (CRM) and the 3 + 3 design, require each patient or a cohort of patients to be fully evaluated for the dose-limit...

journal_title：Statistics in medicine

authors： Polley MY

更新日期：2011-07-30 00:00:00

abstract：:In a cluster randomized cross-over trial, all participating clusters receive both intervention and control treatments consecutively, in separate time periods. Patients recruited by each cluster within the same time period receive the same intervention, and randomization determines order of treatment within a cluster. ...

journal_title：Statistics in medicine

authors： Turner RM,White IR,Croudace T,PIP Study Group.

更新日期：2007-01-30 00:00:00

abstract：:Small but important therapeutic effects of new treatments can be most efficiently detected through the study of large randomized prospective series of patients. Such large scale clinical trials are nowadays commonplace. The alternative is years of polemic and debate surrounding several trials each too small to detect ...

journal_title：Statistics in medicine

authors： McPherson K

更新日期：1982-01-01 00:00:00

abstract：:Cross-sectional designs are often used to monitor the proportion of infections and other post-surgical complications acquired in hospitals. However, conventional methods for estimating incidence proportions when applied to cross-sectional data may provide estimators that are highly biased, as cross-sectional designs t...

journal_title：Statistics in medicine

authors： Fluss R,Mandel M,Freedman LS,Weiss IS,Zohar AE,Haklai Z,Gordon ES,Simchen E

更新日期：2013-06-30 00:00:00

abstract：:This paper presents a statistically optimal exact hypothesis testing procedure for detecting changes in sales adjusted adverse drug reaction (ADR) rates between historical and current periods, with a computer program that implements this test appended. We provide discussions and illustrations on how to monitor ADR rat...

journal_title：Statistics in medicine

authors： Norwood PK,Sampson AR

更新日期：1988-10-01 00:00:00