Comparison of predictive values of two diagnostic tests from the same sample of subjects using weighted least squares.

abstract：:Antimicrobial resistance has become one of the main public health burdens of the last decades, and monitoring the development and spread of non-wild-type isolates has therefore gained increased interest. Monitoring is performed based on the minimum inhibitory concentration (MIC) values, which are collected through the...

journal_title：Statistics in medicine

authors： Jaspers S,Aerts M,Verbeke G,Beloeil PA

更新日期：2014-01-30 00:00:00

abstract：:Correlation is inherent in longitudinal studies due to the repeated measurements on subjects, as well as due to time-dependent covariates in the study. In the National Longitudinal Study of Adolescent to Adult Health (Add Health), data were repeatedly collected on children in grades 7-12 across four waves. Thus, obser...

journal_title：Statistics in medicine

authors： Irimata KM,Broatch J,Wilson JR

更新日期：2019-05-30 00:00:00

abstract：:The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, many of these methodolog...

journal_title：Statistics in medicine

authors： Sauerbrei W,Abrahamowicz M,Altman DG,le Cessie S,Carpenter J,STRATOS initiative.

更新日期：2014-12-30 00:00:00

abstract：:The concept of broad sense agreement (BSA) has recently been proposed for studying the relationship between a continuous measurement and an ordinal measurement. They developed a nonparametric procedure for estimating the BSA index, which is only applicable to completely observed data. In this work, we consider the pro...

journal_title：Statistics in medicine

authors： Dai T,Guo Y,Peng L,Manatunga A

更新日期：2020-06-30 00:00:00

abstract：:In the comparison of two or more treatment groups to a control group, consider a study with non-decreasing repeated measurements of the same characteristic taken over a common set of time points for each subject. Based on the vector of possibly incomplete responses from each subject, this paper considers asymptoticall...

journal_title：Statistics in medicine

authors： Davis CS

更新日期：1996-12-15 00:00:00

abstract：:Funnel plots are widely used to visualize grouped data, for example, in institutional comparison. This paper extends the concept to a multi-level setting, displaying one level at a time, adjusted for the other levels, as well as for covariates at all levels. These level-adjusted funnel plots are based on a Markov chai...

journal_title：Statistics in medicine

authors： Lindhagen L,Darkahi B,Sandblom G,Berglund L

更新日期：2014-09-20 00:00:00

abstract：:The purpose of this research was to develop appropriate methods for analysing repeated ordinal categorical data that arose in an intervention trial to prevent oesophageal cancer. The measured response was the degree of oesophageal dysplasia at 2.5 and 6 years after randomization. An important feature was that some res...

journal_title：Statistics in medicine

authors： Mark SD,Gail MH

更新日期：1994-03-15 00:00:00

abstract：:A study of long term survival of 1487 patients given an allogeneic bone marrow transplant for acute myelogenous leukaemia and 729 patients given a transplant for severe aplastic anaemia was conducted by the International Bone Marrow Transplant Registry. One aim of this study is to determine if the mortality rates of t...

journal_title：Statistics in medicine

authors： Andersen PK,Horowitz MM,Klein JP,Socie G,Stone JV,Zhang MJ

更新日期：1999-06-30 00:00:00

abstract：:Existing methods for power analysis for longitudinal study designs are limited in that they do not adequately address random missing data patterns. Although the pattern of missing data can be assessed during data analysis, it is unknown during the design phase of a study. The random nature of the missing data pattern ...

journal_title：Statistics in medicine

authors： Tu XM,Zhang J,Kowalski J,Shults J,Feng C,Sun W,Tang W

更新日期：2007-07-10 00:00:00

abstract：:Binary matched-pairs data occur commonly in longitudinal studies, such as in cross-over experiments. Many analyses for comparing the matched probabilities of a particular outcome do not utilize pairs having the same outcome for each observation. An example is McNemar's test. Some methodologists find this to be counter...

journal_title：Statistics in medicine

authors： Agresti A,Min Y

更新日期：2004-01-15 00:00:00

abstract：:Modelling disease clustering over space and time can be helpful in providing indications of possible exposures and planning corresponding public health practices. Though a considerable number of studies focus on modelling spatio-temporal patterns of disease, most of them do not directly model a spatio-temporal cluster...

journal_title：Statistics in medicine

authors： Yan P,Clayton MK

更新日期：2006-03-15 00:00:00

abstract：:Exposure to a carcinogen is likely to be reflected by temporal clustering of cancer cases among the community members. Detection of such clustering is a complicated task in general and more so in a small workplace community with low turnover rate. In this study we applied the CUSCORE test and the q-interval statistic ...

journal_title：Statistics in medicine

authors： Chen R,Froom P

更新日期：2003-10-15 00:00:00

abstract：:We consider the use of the assurance method in clinical trial planning. In the assurance method, which is an alternative to a power calculation, we calculate the probability of a clinical trial resulting in a successful outcome, via eliciting a prior probability distribution about the relevant treatment effect. This i...

journal_title：Statistics in medicine

authors： Ren S,Oakley JE

更新日期：2014-01-15 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：:In medical and health studies, heterogeneities in clustered count data have been traditionally modeled by positive random effects in Poisson mixed models; however, excessive zeros often occur in clustered medical and health count data. In this paper, we consider a three-level random effects zero-inflated Poisson model...

journal_title：Statistics in medicine

authors： Ma R,Hasan MT,Sneddon G

更新日期：2009-08-15 00:00:00

abstract：:Epidemiologic and clinical studies routinely collect longitudinal measures of multiple outcomes, including biomarker measures, cognitive functions, and clinical symptoms. These longitudinal outcomes can be used to establish the temporal order of relevant biological processes and their association with the onset of cli...

journal_title：Statistics in medicine

authors： Yang L,Gao S

更新日期：2013-03-15 00:00:00

abstract：:In biomedical studies and clinical trials, repeated measures are often subject to some upper and/or lower limits of detection. Hence, the responses are either left or right censored. A complication arises when more than one series of responses is repeatedly collected on each subject at irregular intervals over a perio...

journal_title：Statistics in medicine

authors： Lachos VH,A Matos L,Castro LM,Chen MH

更新日期：2019-03-15 00:00:00

abstract：:New combination regimens evaluated in phase II cancer clinical trials often show promising results compared to the standard therapy for a disease system. Selection of patients with a better prognosis can be a prominent factor for this optimism. For most disease systems, prognostic variables that are related to the out...

journal_title：Statistics in medicine

authors： Mazumdar M,Fazzari M,Panageas KS

更新日期：2001-03-30 00:00:00

abstract：:The need for resource-intensive laboratory assays to assess exposures in many epidemiologic studies provides ample motivation to consider study designs that incorporate pooled samples. In this paper, we consider the case in which specimens are combined for the purpose of determining the presence or absence of a pool-w...

journal_title：Statistics in medicine

authors： Lyles RH,Tang L,Lin J,Zhang Z,Mukherjee B

更新日期：2012-09-28 00:00:00

abstract：:Multilevel mixed effects survival models are used in the analysis of clustered survival data, such as repeated events, multicenter clinical trials, and individual participant data (IPD) meta-analyses, to investigate heterogeneity in baseline risk and covariate effects. In this paper, we extend parametric frailty model...

journal_title：Statistics in medicine

authors： Crowther MJ,Look MP,Riley RD

更新日期：2014-09-28 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：:We consider the problem of identifying a subgroup of patients who may have an enhanced treatment effect in a randomized clinical trial, and it is desirable that the subgroup be defined by a limited number of covariates. For this problem, the development of a standard, pre-determined strategy may help to avoid the well...

journal_title：Statistics in medicine

authors： Foster JC,Taylor JM,Ruberg SJ

更新日期：2011-10-30 00:00:00

abstract：:Ewell and Ibrahim derived the large sample distribution of the logrank statistic under general local alternatives. Their asymptotic results enable us to extend several group sequential designs which allow for early stopping in favour of the null hypothesis to the setting in which the cure rate model is appropriate. In...

journal_title：Statistics in medicine

authors： Patricia Bernardo MV,Ibrahim JG

更新日期：2000-11-30 00:00:00

abstract：:We examine different methods to pool binary outcomes used both in parallel and cross-over trials. Odds ratio (OR) estimators obtained from joint conditional probabilities in cross-over trials, such as the Mantel-Haenszel and Peto methods, are compared to an OR estimator using marginal results of cross-over trials. Whe...

journal_title：Statistics in medicine

authors： Curtin F,Elbourne D,Altman DG

更新日期：2002-08-15 00:00:00

abstract：:In this article, we investigate procedures for comparing two independent Poisson variates that are observed over unequal sampling frames (i.e. time intervals, populations, areas or any combination thereof). We consider two statistics (with and without the logarithmic transformation) for testing the equality of two Poi...

journal_title：Statistics in medicine

authors： Ng HK,Tang ML

更新日期：2005-03-30 00:00:00

abstract：:Combinatorial drugs have been widely applied in disease treatment, especially chemotherapy for cancer, due to its improved efficacy and reduced toxicity compared with individual drugs. The study of combinatorial drugs requires efficient experimental designs and proper follow-up statistical modeling techniques. Linear ...

journal_title：Statistics in medicine

authors： Xiao Q,Wang L,Xu H

更新日期：2019-01-30 00:00:00

abstract：:For clinical trials with multiple treatment arms or endpoints a variety of sequentially rejective, weighted Bonferroni-type tests have been proposed, such as gatekeeping procedures, fixed sequence tests, and fallback procedures. They allow to map the difference in importance as well as the relationship between the var...

journal_title：Statistics in medicine

authors： Bretz F,Maurer W,Brannath W,Posch M

更新日期：2009-02-15 00:00:00

abstract：:Piecewise constant incidence models were developed to estimate the force of infection in women from age- and time-specific antenatal or neonatal seroprevalence data. Differential inclusion of infected women in sero-surveys compared to uninfected women was taken into account, with respect to both changes in inclusion r...

journal_title：Statistics in medicine

authors： Ades AE,Medley GF

更新日期：1994-09-30 00:00:00

abstract：:Longitudinal studies with repeated measures are often subject to non-response. Methods currently employed to alleviate the difficulties caused by missing data are typically unsatisfactory, especially when the cause of the missingness is related to the outcomes. We present an approach for incomplete categorical data in...

journal_title：Statistics in medicine

authors： West CP,Dawson JD

更新日期：2002-01-30 00:00:00

abstract：:The weighted average treatment effect is a causal measure for the comparison of interventions in a specific target population, which may be different from the population where data are sampled from. For instance, when the goal is to introduce a new treatment to a target population, the question is what efficacy (or ef...

journal_title：Statistics in medicine

authors： Tao Y,Fu H

更新日期：2019-02-10 00:00:00