On prediction of future observation in growth curve model.

abstract：:Two important qualities of controlled clinical trials are that they reduce dependence on historical standards for evaluating therapy and separate the effect of treatment from the confounding influence of time. Whatever the theory of the clinical trial, however, time has not easily been banished from the analysis of me...

journal_title：Statistics in medicine

authors： Senn SJ

更新日期：1989-11-01 00:00:00

abstract：:In this paper, we argue that causal effect models for realistic individualized treatment rules represent an attractive tool for analyzing sequentially randomized trials. Unlike a number of methods proposed previously, this approach does not rely on the assumption that intermediate outcomes are discrete or that models ...

journal_title：Statistics in medicine

authors： Bembom O,van der Laan MJ

更新日期：2008-08-30 00:00:00

abstract：:This paper describes statistical procedures for use in an experiment that compares two handwashing protocols. The evaluation of a handwashing protocol entails collection of the wash effluent. Colony counts for the effluent reflect the number of flora removed by the wash protocol. The analysis aims to formulate and est...

journal_title：Statistics in medicine

authors： Le CT

更新日期：1986-07-01 00:00:00

abstract：:Proportional hazards (or Cox) regression is a popular method for modelling the effects of prognostic factors on survival. Use of cubic spline functions to model time-by-covariate interactions in Cox regression allows investigation of the shape of a possible covariate-time dependence without having to specify a specifi...

journal_title：Statistics in medicine

authors： Hess KR

更新日期：1994-05-30 00:00:00

abstract：:Generalized linear models may be extended in several ways. This paper describes five such extensions: (i) generalized additive models; (ii) the use of quasi-likelihood; (iii) joint modelling of mean and dispersion; (iv) introduction of extra random components to give hierarchical generalized linear models; (v) modelli...

journal_title：Statistics in medicine

authors： Nelder JA

更新日期：1998-12-15 00:00:00

abstract：:In the recent years, studies of hepatitis B (HBV) and hepatitis C virus (HCV) dynamics have drawn great attention as they provide insight into the process of virus elimination/production and of infected cells decay during antiviral treatment. Estimates of viral dynamic parameters may be used to determine the lifetime ...

journal_title：Statistics in medicine

authors： Sypsa V,Hatzakis A

更新日期：2008-12-30 00:00:00

abstract：:We discuss some of the statistical approaches to the design and analysis of phase I clinical trials in cancer. An attempt is made to identify the issues, particular to this type of trial, that should be addressed by an appropriate methodology. A brief review of schemes currently in use is provided together with our vi...

journal_title：Statistics in medicine

authors： O'Quigley J,Chevret S

更新日期：1991-11-01 00:00:00

abstract：:Nutritional exposures are often measured with considerable error in commonly used surrogate instruments such as the food frequency questionnaire (FFQ) (denoted by Q(i) for the ith subject). The error can be both systematic and random. The diet record (DR) denoted by R(i) for the ith subject is considered an alloyed go...

journal_title：Statistics in medicine

authors： Rosner B,Michels KB,Chen YH,Day NE

更新日期：2008-08-15 00:00:00

abstract：:The receiver operating characteristic (ROC) curve can be utilized to evaluate the performance of diagnostic tests. The area under the ROC curve (AUC) is a widely used summary index for comparing multiple ROC curves. Both parametric and nonparametric methods have been developed to estimate and compare the AUCs. However...

journal_title：Statistics in medicine

authors： Yao W,Li Z,Graubard BI

更新日期：2015-04-15 00:00:00

abstract：:Instrumental variable estimates of causal effects can be biased when using many instruments that are only weakly associated with the exposure. We describe several techniques to reduce this bias and estimate corrected standard errors. We present our findings using a simulation study and an empirical application. For th...

journal_title：Statistics in medicine

authors： Davies NM,von Hinke Kessler Scholder S,Farbmacher H,Burgess S,Windmeijer F,Smith GD

更新日期：2015-02-10 00:00:00

abstract：:In this paper, we discuss family-based association test (FBATs) relating genetic data to survival and time-to-onset data. We show how the standard logrank and Wilcoxon statistics can be used with family data to develop tests of association. We prove that the FBAT-logrank approach can be identical to the proportional h...

journal_title：Statistics in medicine

authors： Lange C,Blacker D,Laird NM

更新日期：2004-01-30 00:00:00

abstract：:In standard time-to-event or survival analysis, occurrence times of the event of interest are observed exactly or are right-censored, meaning that it is only known that the event occurred after the last observation time. There are numerous methods available for estimating the survival curve and for testing and estimat...

journal_title：Statistics in medicine

authors： Lindsey JC,Ryan LM

更新日期：1998-01-30 00:00:00

abstract：:The World Health Organization and collaborating institutions in four developing countries have conducted a multi-centre randomized controlled trial, in which clinics were allocated at random to two antenatal care (ANC) models. These were the standard 'Western' ANC model and a 'new' ANC model consisting of tests, clini...

journal_title：Statistics in medicine

authors： Piaggio G,Carroli G,Villar J,Pinol A,Bakketeig L,Lumbiganon P,Bergsjø P,Al-Mazrou Y,Ba'aqeel H,Belizán JM,Farnot U,Berendes H,WHO Antenatal Care Trial Research Group.

更新日期：2001-02-15 00:00:00

abstract：:Rationalization of antibiotic therapy in the management of infectious diseases is helped by a knowledge of the patterns of sensitivity and resistance of bacteria to antibiotics and their possible changes both in time and from one hospital unit to another. In this paper we present the results regarding the sensitivitie...

journal_title：Statistics in medicine

authors： Bonetto C,Giannerini S,Giovagnoli A

更新日期：2006-10-30 00:00:00

abstract：:In clinical trials, treatment comparisons are often performed by models that incorporate important prognostic factors. Since these models require complete covariate information on all patients, statisticians frequently resort to complete case analysis or to omission of an important covariate. A probability imputation ...

journal_title：Statistics in medicine

authors： Schemper M,Smith TL

更新日期：1990-07-01 00:00:00

abstract：:In the study of multiple failure times for the same subjects, for example, recurrent infections for patients with a given disease, there are often subject effects, that is, subjects have different risks that cannot be explained by known covariates. Standard methods, which ignore subject effects, lead to overestimation...

journal_title：Statistics in medicine

authors： Yau KK,McGilchrist CA

更新日期：1998-06-15 00:00:00

abstract：:This article concerns construction of a confidence surface for tangential slopes of the dose-response surface of a combination therapy to identify where response increases as a function of drug dosage. This approach extends to the assessment of the effectiveness of the combination therapy. ...

journal_title：Statistics in medicine

authors： Hung HM

更新日期：1992-03-01 00:00:00

abstract：:Juvenile dermatomyositis (JDM) is a rare autoimmune disease that may lead to serious complications, even to death. We develop a 2-state Markov regression model in a Bayesian framework to characterise disease progression in JDM over time and gain a better understanding of the factors influencing disease risk. The trans...

journal_title：Statistics in medicine

authors： De Iorio M,Gallot N,Valcarcel B,Wedderburn L

更新日期：2018-05-10 00:00:00

abstract：:Multi-type recurrent event data arise when two or more different kinds of events may occur repeatedly over a period of observation. The scientific objectives in such settings are often to describe features of the marginal processes and to study the association between the different types of events. Interval-censored m...

journal_title：Statistics in medicine

authors： Chen BE,Cook RJ,Lawless JF,Zhan M

更新日期：2005-03-15 00:00:00

abstract：:The analysis of patient-reported outcomes or other psychological traits can be realized using the Rasch measurement model. When the objective of a study is to compare groups of individuals, it is important, before the study, to define a sample size such that the group comparison test will attain a given power. The Ras...

journal_title：Statistics in medicine

authors： Hardouin JB,Blanchin M,Feddag ML,Le Néel T,Perrot B,Sébille V

更新日期：2015-07-20 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：:I discuss alternatives to the one compartment model, delta Yt = alpha + beta exp(- gamma t). Instead of comparing the one and two compartment models, I derive statistics for testing mixtures of the parameters (beta, gamma) in the one compartment model. I apply the proposed methods to the problem of hydrogen clearance ...

journal_title：Statistics in medicine

authors： Zelterman D

更新日期：1989-08-01 00:00:00

abstract：:The intraclass correlation coefficient rho plays a key role in the design of cluster randomized trials. Estimates of rho obtained from previous cluster trials and used to inform sample size calculation in planned trials may be imprecise due to the typically small numbers of clusters in such studies. It may be useful t...

journal_title：Statistics in medicine

authors： Ukoumunne OC,Davison AC,Gulliford MC,Chinn S

更新日期：2003-12-30 00:00:00

abstract：:Subjects in randomized controlled trials do not always comply to the treatment condition they have been assigned to. This may cause the estimated effect of the intervention to be biased and also affect efficiency, coverage of confidence intervals, and statistical power. In cluster randomized trials non-compliance may ...

journal_title：Statistics in medicine

authors： Moerbeek M,Schie SV

更新日期：2019-11-20 00:00:00

abstract：:Many reactions in enzymology are governed by the Michaelis-Menten equation. Characterising these reactions requires the estimation of the parameters K(M) and V(max) which determine the Michaelis-Menten equation and this is done by observing rates of reactions at a set of substrate concentrations. The choice of substra...

journal_title：Statistics in medicine

authors： Matthews JN,Allcock GC

更新日期：2004-02-15 00:00:00

abstract：:Bivariate survival data arise, for example, in twin studies and studies of both eyes or ears of the same individual. Often it is of interest to regress the survival times on a set of predictors. In this paper we extend Wei and Tanner's multiple imputation approach for linear regression with univariate censored data to...

journal_title：Statistics in medicine

authors： Pan W,Kooperberg C

更新日期：1999-11-30 00:00:00

abstract：:Genetic networks for gene expression data are often built by graphical models, which in turn are built from pair-wise correlations of gene expression levels. A key feature of building graphical models is the evaluation of conditional independence of two traits, given other traits. When conditional independence can be ...

journal_title：Statistics in medicine

authors： Yu Z,Wang L,Hildebrandt MA,Schaid DJ

更新日期：2008-08-30 00:00:00

abstract：:Novel methodology is implemented to assess the predictive power of covariate information associated with sequential binary events. Logistic models are first fitted on the basis of a subset of the observations and then evaluated sequentially on the rest. The probabilistic forecasts are compared to the outcomes via a sc...

journal_title：Statistics in medicine

authors： Seillier-Moiseiwitsch F

更新日期：1996-10-30 00:00:00

abstract：:In order for national statistical offices to maintain the trust of the public to collect data and publish statistics of importance to society and decision-making, it is imperative that respondents (persons or establishments) be guaranteed privacy and confidentiality in return for providing requested confidential data....

journal_title：Statistics in medicine

authors： Gonzalez JF Jr,Cox LH

更新日期：2005-02-28 00:00:00

abstract：:Longitudinal studies are often concerned with estimating the recurrence rate of a non-fatal event. In many cases, only the total number of events occurring during successive time intervals is known. We compared a mixed Poisson-gamma regression method proposed by Thall and a quasi-likelihood method proposed by Zeger an...

journal_title：Statistics in medicine

authors： Stukel TA

更新日期：1993-07-30 00:00:00