Flexible longitudinal linear mixed models for multiple censored responses data.

abstract：:Clustered grouped survival data arise naturally in clinical medicine and biological research. For example, in a randomized clinical trial, the variable of interest is the time to occurrence of a certain event with or without a new treatment and the data are collected from possibly correlated subjects from independent ...

journal_title：Statistics in medicine

authors： Lam KF,Ip D

更新日期：2003-06-30 00:00:00

abstract：:Correlated response data arise often in biomedical studies. The generalized estimation equation (GEE) approach is widely used in regression analysis for such data. However, there are few methods available to check the adequacy of regression models in GEE. In this paper, a graphical method is proposed based on Cook and...

journal_title：Statistics in medicine

authors： Pan W,Connett JE,Porzio GC,Weisberg S

更新日期：2001-10-15 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：:We propose a goodness-of-fit test statistic for linear regression with heterogeneous variance, which is asymptotically chi-square if the given model is correct. The test statistic is computed as a quadratic form of observed minus predicted responses. We apply the method to a linear regression for an ordinal categorica...

journal_title：Statistics in medicine

authors： Lipsitz SR,Buoncristiani JF

更新日期：1994-01-30 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：: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：:A new goodness-of-fit test for the logistic regression model is proposed. It exploits the property of this model that when it is correct, i.e. not misspecified, the parameter estimates are (asymptotically) invariant under reweighting the observations by weights wi that are a function of the binary (0/1) outcomes yi. M...

journal_title：Statistics in medicine

authors： Nagelkerke N,Smits J,le Cessie S,van Houwelingen H

更新日期：2005-01-15 00:00:00

abstract：:Logistic regression analysis may well be used to develop a prognostic model for a dichotomous outcome. Especially when limited data are available, it is difficult to determine an appropriate selection of covariables for inclusion in such models. Also, predictions may be improved by applying some sort of shrinkage in t...

journal_title：Statistics in medicine

authors： Steyerberg EW,Eijkemans MJ,Harrell FE Jr,Habbema JD

更新日期：2000-04-30 00:00:00

abstract：:Quality of life (QOL) assessment is a key component of many clinical studies and frequently requires the use of single global summary measures that capture the overall balance of findings from a potentially wide-ranging assessment of QOL issues. We propose and evaluate an irregular multilevel latent variable model sui...

journal_title：Statistics in medicine

authors： Kifley A,Heller GZ,Beath KJ,Bulger D,Ma J,Gebski V

更新日期：2012-05-20 00:00:00

abstract：:Meta-analysis has generally been accepted as a fundamental tool for combining effect estimates from several studies. For binary studies with rare events, the Peto odds ratio (POR) method has become the relative effect estimator of choice. However, the POR leads to biased estimates for the OR when treatment effects are...

journal_title：Statistics in medicine

authors： Brockhaus AC,Bender R,Skipka G

更新日期：2014-12-10 00:00:00

abstract：:We study prevalence-dependent diagnostic accuracy measures, specifically, positive and negative predictive values. These measures permit an assessment of the clinical utility of diagnostic tests across populations with different disease prevalences. In many cases, prevalence may not be known with certainty and the eva...

journal_title：Statistics in medicine

authors： Li J,Fine JP,Safdar N

更新日期：2007-07-30 00:00:00

abstract：:This paper is a compendium of exact and asymptotic formulae and tables for estimating the sample size in a clinical trial with two treatment groups and a dichotomous outcome. The paper provides separate formulae for equal and unequal treatment group sizes, formulae for the calculation of power given the sample size, a...

journal_title：Statistics in medicine

authors： Sahai H,Khurshid A

更新日期：1996-01-15 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：:In some randomized controlled trials, subjects with a better prognosis may be diverted into the treatment group. This subverting of randomization results in an unobserved non-compliance with the originally intended treatment assignment. Consequently, the estimate of treatment effect from these trials may be biased. Th...

journal_title：Statistics in medicine

authors： Marcus SM

更新日期：2001-02-28 00:00:00

abstract：:This field study sought to measure the effects of dental delivery and school-based, dental health education on use of dental health care by children in grades K-6. We attempted to control for two potential confounding factors by an approximate randomization of children into treatment groups with stratification on grad...

journal_title：Statistics in medicine

authors： Oler J,Bentley JM

更新日期：1983-01-01 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：:In many epidemiological studies it is common to resort to regression models relating incidence of a disease and its risk factors. The main goal of this paper is to consider inference on such models with error-prone observations and variances of the measurement errors changing across observations. We suppose that the o...

journal_title：Statistics in medicine

authors： de Castro M,Galea M,Bolfarine H

更新日期：2008-11-10 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：:This paper, arising out of an event to honour the statistical and scientific contributions of Professor Peter Armitage, is concerned with research strategies and needs for chronic disease prevention. A few highlights from recent intervention trials for the prevention of cancer, cardiovascular disease, fractures and di...

journal_title：Statistics in medicine

authors： Prentice RL

更新日期：2004-11-30 00:00:00

abstract：:It is often of interest to use observational data to estimate the causal effect of a target exposure or treatment on an outcome. When estimating the treatment effect, it is essential to appropriately adjust for selection bias due to observed confounders using, for example, propensity score weighting. Selection bias du...

journal_title：Statistics in medicine

authors： Parast L,Griffin BA

更新日期：2020-08-15 00:00:00

abstract：:In many medical applications, combining information from multiple biomarkers could yield a better diagnosis than any single one on its own. When there is a lack of a gold standard, an algorithm of classifying subjects into the case and non-case status is necessary for combining multiple markers. The aim of this paper ...

journal_title：Statistics in medicine

authors： Zhang J,Zhang Y,Chaloner K,Stapleton JT

更新日期：2016-04-15 00:00:00

abstract：:We consider methods for selecting the joint specification of the mean and variance functions in statistical models for rates or counts. Based on analyses of diagnosis-specific hospital discharge rates in Michigan, we show that a Poisson model with an extra variance component for the systematic variation is superior to...

journal_title：Statistics in medicine

authors： Wolfe RA,Petroni GR,McLaughlin CG,McMahon LF Jr

更新日期：1991-09-01 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：:This paper discusses the various philosophies that influence the selection of patients for entry into randomized controlled trials. Although a number of different and often competing issues have to be considered depending upon the trial, keeping entry criteria simple, wide and at times even flexible is usually prefera...

journal_title：Statistics in medicine

authors： Yusuf S,Held P,Teo KK,Toretsky ER

更新日期：1990-01-01 00:00:00

abstract：:If the sample size for a t-test is calculated on the basis of a prior estimate of the variance then the power of the test at the treatment difference of interest is not robust to misspecification of the variance. We propose a t-test for a two-treatment comparison based on Stein's two-stage test which involves the use ...

journal_title：Statistics in medicine

authors： Denne JS,Jennison C

更新日期：1999-07-15 00:00:00

abstract：:Statistical modeling methods have had increasing use in drug disposition studies, both to estimate pharmacokinetic parameters and to develop regression models that relate these parameter estimates to patient characteristics. These methods are particularly flexible as they allow non-linearity and sparse within-patient ...

journal_title：Statistics in medicine

authors： Roe DJ

更新日期：1997-06-15 00:00:00

abstract：:Cox proportional hazard regression model is a popular tool to analyze the relationship between a censored lifetime variable with other relevant factors. The semiparametric Cox model is widely used to study different types of data arising from applied disciplines such as medical science, biology, and reliability studie...

journal_title：Statistics in medicine

authors： Ghosh A,Basu A

更新日期：2019-11-30 00:00:00

abstract：:Disease incidence predictions are useful for a number of administrative and scientific purposes. The simplest ones are made using trend extrapolation, on either an arithmetic or a logarithmic scale. This paper shows how approximate confidence prediction intervals can be calculated for such predictions, both for the to...

journal_title：Statistics in medicine

authors： Hakulinen T,Dyba T

更新日期：1994-08-15 00:00:00

abstract：:Studies in health research are commonly carried out in clustered settings, where the individual response data are correlated within clusters. Estimation and modelling of the extent of between-cluster variation contributes to understanding of the current study and to design of future studies. It is common to express be...

journal_title：Statistics in medicine

authors： Turner RM,Omar RZ,Thompson SG

更新日期：2006-05-15 00:00:00

abstract：:Hypothesis testing, in which the null hypothesis specifies no difference between treatment groups, is an important tool in the assessment of new medical interventions. For randomized clinical trials, permutation tests that reflect the actual randomization are design-based analyses for such hypotheses. This means that ...

journal_title：Statistics in medicine

authors： Berger VW

更新日期：2000-05-30 00:00:00