Hypothesis testing in the polychotomous logistic model with an application to detecting gastrointestinal cancer.

abstract：:Longitudinal studies are commonly used to study processes of change. Because data are collected over time, missing data are pervasive in longitudinal studies, and complete ascertainment of all variables is rare. In this paper a new imputation strategy for completing longitudinal data sets is proposed. The proposed met...

journal_title：Statistics in medicine

authors： Landrum MB,Becker MP

更新日期：2001-09-15 00:00:00

abstract：:Clinical trials, especially the randomized clinical trial, have been and will remain the gold standard for the evaluation of new interventions, including pharmaceuticals, biologics, medical devices, procedures, or behavioral modifications. Despite more than five decades of experience, there are still challenges in the...

journal_title：Statistics in medicine

authors： DeMets DL

更新日期：2012-11-10 00:00:00

abstract：:The microbiome plays an important role in human health by mediating the path from environmental exposures to health outcomes. The relative abundances of the high-dimensional microbiome data have an unit-sum restriction, rendering standard statistical methods in the Euclidean space invalid. To address this problem, we ...

journal_title：Statistics in medicine

authors： Zhang H,Chen J,Feng Y,Wang C,Li H,Liu L

更新日期：2021-02-20 00:00:00

abstract：:We consider a general model for anomaly detection in a longitudinal cohort mortality pattern based on logistic joinpoint regression with unknown joinpoints. We discuss backward and forward sequential procedures for selecting both the locations and the number of joinpoints. Estimation of the model parameters and the se...

journal_title：Statistics in medicine

authors： Czajkowski M,Gill R,Rempala G

更新日期：2008-04-30 00:00:00

abstract：:Interval-censored survival data often occur in medical studies, especially in clinical trials. In this case, many authors have considered estimation of a survival function. There is, however, relatively little discussion on estimating the variance of estimated survival functions. For right-censored data, a special cas...

journal_title：Statistics in medicine

authors： Sun J

更新日期：2001-04-30 00:00:00

abstract：:In genetic and genomic studies, gene-environment (G×E) interactions have important implications. Some of the existing G×E interaction methods are limited by analyzing a small number of G factors at a time, by assuming linear effects of E factors, by assuming no data contamination, and by adopting ineffective selection...

journal_title：Statistics in medicine

authors： Wu C,Shi X,Cui Y,Ma S

更新日期：2015-12-30 00:00:00

abstract：:One Sentence Summary: A Bayesian repeated measures model based on quantitative muscle strength data from a prospective Natural History Study was developed to determine disease progression and design clinical trials for GNE myopathy, a rare and slowly progressive muscle disease. GNE myopathy is a rare muscle disease ch...

journal_title：Statistics in medicine

authors： Quintana M,Shrader J,Slota C,Joe G,McKew JC,Fitzgerald M,Gahl WA,Berry S,Carrillo N

更新日期：2019-04-15 00:00:00

abstract：:In the last decade or so, pharmaceutical drug development activities in the area of new antibacterial drugs for treating serious bacterial diseases have declined, and at the same time, there are worries that the increased prevalence of antibiotic-resistant bacterial infections, especially the increase in drug-resistan...

journal_title：Statistics in medicine

authors： Huque MF,Valappil T,Soon GG

更新日期：2014-11-10 00:00:00

abstract：:To summarize safety data such as clinical adverse experiences in clinical trials with a moderate to long-term follow-up, we may use a measurement which accounts for the potential differences in the follow-up duration between treatment groups. The incidence rate, which uses the total person-time follow-up in a treatmen...

journal_title：Statistics in medicine

authors： Liu GF,Wang J,Liu K,Snavely DB

更新日期：2006-04-30 00:00:00

abstract：:We consider recurrent events of the same type that occur during alternating restraint and non-restraint time periods. This research is motivated by a study on juvenile recidivism, where the probationers were followed for re-offenses during alternating placement periods and free-time periods. During the placement perio...

journal_title：Statistics in medicine

authors： Li X,Chen Y,Li R

更新日期：2017-02-20 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：:The aim of this paper is to demonstrate the effect of excluding incomplete observations and competing events when calculating cross-sectional measures of NHS waiting times, and to obtain a more accurate estimate of the 'time-to-admission' of those listed on NHS waiting lists using life-table methods. The official 'tim...

journal_title：Statistics in medicine

authors： Armstrong PW

更新日期：2000-08-15 00:00:00

abstract：:The purpose of this paper is to show that the sensitivity and specificity estimates obtained by 'discrepant analysis' are biased. Discrepant analysis is a widely used technique that attempts to provide estimates of sensitivity and specificity in the presence of an imperfect gold standard. Many researchers have applied...

journal_title：Statistics in medicine

authors： Hadgu A

更新日期：1997-06-30 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：: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：:Suppression of premature ventricular contractions (PVCs) is one of the goals of antiarrhythmic therapy. In a clinical trial, however, it may be difficult to distinguish antiarrhythmic drug effect from spontaneous variation in PVCs. We propose the application of linear regression to PVC histories to ascertain drug effe...

journal_title：Statistics in medicine

authors： Berry DA,Fox TL

更新日期：1983-07-01 00:00:00

abstract：:There are many settings in which the distribution of error in a mismeasured covariate varies with the value of another covariate. Take, for example, the case of HIV phylogenetic cluster size, large values of which are an indication of rapid HIV transmission. Researchers wish to find behavioral correlates of HIV phylog...

journal_title：Statistics in medicine

authors： Parveen N,Moodie E,Brenner B

更新日期：2017-07-30 00:00:00

abstract：:The introduction of potent antiretroviral therapies for treatment of HIV infection typically results in a dramatic reduction in plasma HIV RNA concentration, often to levels undetectable by current measurement practices. However, although a high proportion of patients achieve 'undetectability', many then experience a ...

journal_title：Statistics in medicine

authors： McKinnon EJ,James IR,John M,Mallal SA

更新日期：2003-02-15 00:00:00

abstract：:Testing the equality of 2 proportions for a control group versus a treatment group is a well-researched statistical problem. In some settings, there may be strong historical data that allow one to reliably expect that the control proportion is one, or nearly so. While one-sample tests or comparisons to historical cont...

journal_title：Statistics in medicine

authors： Gabriel EE,Nason M,Fay MP,Follmann DA

更新日期：2018-03-30 00:00:00

abstract：:Surrogate endpoint validation has been well established by the meta-analytical correlation-based approach as outlined in the seminal work of Buyse et al. (Biostatistics, 2000). Surrogacy can be assumed if strong associations on individual and study levels can be demonstrated. Alternatively, if an effect on a true endp...

journal_title：Statistics in medicine

authors： Schürmann C,Sieben W

更新日期：2016-03-30 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：:We consider counting process methods for analysing time-to-event data with multiple or recurrent outcomes, using the models developed by Anderson and Gill, Wei, Lin and Weissfeld and Prentice, Williams and Peterson. We compare the methods, and show how to implement them using popular statistical software programs. By ...

journal_title：Statistics in medicine

authors： Therneau TM,Hamilton SA

更新日期：1997-09-30 00:00:00

abstract：:For the analysis of time to event data in contraceptive studies when individuals are subject to competing causes for discontinuation, some authors have recently advocated the use of the cumulative incidence rate as a more appropriate measure to summarize data than the complement of the Kaplan-Meier estimate of discont...

journal_title：Statistics in medicine

authors： Farley TM,Ali MM,Slaymaker E

更新日期：2001-12-15 00:00:00

abstract：:We describe the usual statistical concepts and consequent appropriate simulations of a prospective study for the simple case of a single risk variable and an assumed logistic model. We examine the simulations of Lilienfeld and Pyne, and show that they are seriously flawed. Contrary to those authors' claims, the estima...

journal_title：Statistics in medicine

authors： Halperin M,Abbott RD,Blackwelder WC,Jacobowitz R,Lan KK,Verter JI,Wedel H

更新日期：1985-04-01 00:00:00

abstract：:We develop reinforcement learning trials for discovering individualized treatment regimens for life-threatening diseases such as cancer. A temporal-difference learning method called Q-learning is utilized that involves learning an optimal policy from a single training set of finite longitudinal patient trajectories. A...

journal_title：Statistics in medicine

authors： Zhao Y,Kosorok MR,Zeng D

更新日期：2009-11-20 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：:We studied the problem of testing a hypothesized distribution in survival regression models when the data is right censored and survival times are influenced by covariates. A modified chi-squared type test, known as Nikulin-Rao-Robson statistic, is applied for the comparison of accelerated failure time models. This st...

journal_title：Statistics in medicine

authors： Tahir MR,Tran QX,Nikulin MS

更新日期：2017-05-30 00:00:00

abstract：:This paper presents a general approach for simultaneously assessing, from serial data, diagnostic consistency, interrater reliability and incidence of a strictly progressive disease. Observed data are viewed as incomplete: diagnostic errors are not distinguished from true diagnoses. We introduce a broad class of model...

journal_title：Statistics in medicine

authors： Espeland MA,Murphy WC,Leverett DH

更新日期：1988-03-01 00:00:00

abstract：:The primary purpose of a disease surveillance system is to provide data for the detection of changes in the incidence of the disease. Methods for the analysis of data from surveillance systems are reviewed. A new procedure is proposed for use when the system includes geographically dispersed reporting units, such as h...

journal_title：Statistics in medicine

authors： Raubertas RF

更新日期：1989-03-01 00:00:00

abstract：:Frailty models are encountered in many medical applications, yet little research has been devoted to develop measures that quantify the predictive ability of these models. In this paper, we elaborate on the concept of the concordance probability to clustered data, resulting in an 'Overall Conditional C-index' or bfC(O...

journal_title：Statistics in medicine

authors： Van Oirbeek R,Lesaffre E

更新日期：2010-12-30 00:00:00