Identifying the types of missingness in quality of life data from clinical trials.

abstract：:Summarizing the information of many studies using a meta-analysis becomes more and more important, also in the field of diagnostic studies. The special challenge in meta-analysis of diagnostic accuracy studies is that in general sensitivity and specificity are co-primary endpoints. Across the studies both endpoints ar...

journal_title：Statistics in medicine

authors： Zapf A,Hoyer A,Kramer K,Kuss O

更新日期：2015-12-20 00:00:00

abstract：:For time-to-event outcomes, a rich literature exists on the bias introduced by covariate measurement error in regression models, such as the Cox model, and methods of analysis to address this bias. By comparison, less attention has been given to understanding the impact or addressing errors in the failure time outcome...

journal_title：Statistics in medicine

authors： Oh EJ,Shepherd BE,Lumley T,Shaw PA

更新日期：2018-04-15 00:00:00

abstract：:In this paper we give an informal introduction to a robust method for survival analysis which is based on a modification of the usual partial likelihood estimator (PLE). Large sample results lead us to expect reduced bias for this robust estimator compared with the PLE whenever there are even slight violations of the ...

journal_title：Statistics in medicine

authors： Minder CE,Bednarski T

更新日期：1996-05-30 00:00:00

abstract：:In this paper, we develop a method for the simultaneous estimation of spectral density functions (SDFs) for a collection of stationary time series that share some common features. Due to the similarities among the SDFs, the log-SDF can be represented using a common set of basis functions. The basis shared by the colle...

journal_title：Statistics in medicine

authors： Maadooliat M,Sun Y,Chen T

更新日期：2018-12-30 00:00:00

abstract：:Having a surrogate for a definitive endpoint in a clinical trial can sometimes be useful when it is impractical, invasive or very time consuming to obtain the definitive endpoint. This paper discusses methods for assessing whether the surrogate-endpoint results of a trial can be used in place of definitive-endpoint re...

journal_title：Statistics in medicine

authors： Korn EL,Albert PS,McShane LM

更新日期：2005-01-30 00:00:00

abstract：:Graphical methods are often used to check goodness-of-fit of models to data. It is common to plot residuals against a reference distribution so that when the model fits the data, the configuration should be close to a straight line. Since the resemblance to a straight line is often unclear, it has been suggested to ad...

journal_title：Statistics in medicine

authors： Cohen A,Barnett O

更新日期：1995-08-30 00:00:00

abstract：:Providing personalized treatments designed to maximize benefits and minimizing harms is of tremendous current medical interest. One problem in this area is the evaluation of the interaction between the treatment and other predictor variables. Treatment effects in subgroups having the same direction but different magni...

journal_title：Statistics in medicine

authors： Chen W,Ghosh D,Raghunathan TE,Norkin M,Sargent DJ,Bepler G

更新日期：2012-12-10 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：:The Jimma Infant Survival Differential Longitudinal Study is an Ethiopian study, set up to establish risk factors affecting infant survival and to investigate socio-economic, maternal and infant-rearing factors that contribute most to the child's early survival. Here, a subgroup of about 1500 children born in Jimma to...

journal_title：Statistics in medicine

authors： Lesaffre E,Asefa M,Verbeke G

更新日期：1999-04-15 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：: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：:In the medical literature, hundreds of prediction models are being developed to predict health outcomes in individuals. For continuous outcomes, typically a linear regression model is developed to predict an individual's outcome value conditional on values of multiple predictors (covariates). To improve model developm...

journal_title：Statistics in medicine

authors： Riley RD,Snell KIE,Ensor J,Burke DL,Harrell FE Jr,Moons KGM,Collins GS

更新日期：2019-03-30 00:00:00

abstract：:The explanation of heterogeneity plays an important role in meta-analysis. The random effects meta-regression model allows the inclusion of trial-specific covariates which may explain a part of the heterogeneity. We examine the commonly used tests on the parameters in the random effects meta-regression with one covari...

journal_title：Statistics in medicine

authors： Knapp G,Hartung J

更新日期：2003-09-15 00:00:00

abstract：:Hot-deck imputation is an intuitively simple and popular method of accommodating incomplete data. Users of the method will often use the usual multiple imputation variance estimator which is not appropriate in this case. However, no variance expression has yet been derived for this easily implemented method applied to...

journal_title：Statistics in medicine

authors： Reilly M,Pepe M

更新日期：1997-01-15 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：:It is naive and incorrect to use the proportions of successful operations to compare the performance of surgeons because the patients' risk profiles are different. In this paper, we explore the use of risk-adjusted procedures to compare the performance of surgeons. One such risk-adjusted statistic is the standardized ...

journal_title：Statistics in medicine

authors： Tang X,Gan FF

更新日期：2017-07-20 00:00:00

abstract：:Many epidemiologic investigations are designed to study the effects of multiple exposures. Most of these studies are analysed either by fitting a risk-regression model with all exposures forced in the model, or by using a preliminary-testing algorithm, such as stepwise regression, to produce a smaller model. Research ...

journal_title：Statistics in medicine

authors： Greenland S

更新日期：1993-04-30 00:00:00

abstract：:A measure of similarity for response curves is presented and its potential use is discussed. The distribution of a suitable test statistic for testing the independence of the course of two curves is derived. The method proposed is compared with other proposals in the literature for the analysis of paired response curv...

journal_title：Statistics in medicine

authors： Schulgen G

更新日期：1989-11-01 00:00:00

abstract：:A method is presented which allows us to adapt the sample size as well as the number and time points of interim analyses to the treatment difference observed at an interim look during the course of a clinical trial with censored survival time as the endpoint. The method allows the inclusion of data inspections during ...

journal_title：Statistics in medicine

authors： Schäfer H,Müller HH

更新日期：2001-12-30 00:00:00

abstract：:In an individually matched case-control study, effects of potential risk factors are ascertained through conditional logistic regression (CLR). Extension of CLR to situations with multiple disease or reference categories has been made through polychotomous CLR and is shown to be more efficient than carrying out separa...

journal_title：Statistics in medicine

authors： Mukherjee B,Liu I,Sinha S

更新日期：2007-07-30 00:00:00

abstract：:We develop analysis methods for clinical trials with time-to-event outcomes which correct for treatment changes during follow-up, yet are based on comparisons of randomized groups and not of selected groups. A causal model relating observed event times to event times that would have been observed under other treatment...

journal_title：Statistics in medicine

authors： White IR,Babiker AG,Walker S,Darbyshire JH

更新日期：1999-10-15 00:00:00

abstract：:The serial dilution assay (for example, an in vitro antimicrobic susceptibility test or a serum antibody titer assay) is an important technique in biomedical research. The structure of the experiment forces grouping of the threshold concentrations into intervals. Statistical methods to analyse threshold concentrations...

journal_title：Statistics in medicine

authors： Hamilton MA,Rinaldi MG

更新日期：1988-04-01 00:00:00

abstract：:Many observational studies adopt what we call retrospective convenience sampling (RCS). With the sample size in each arm prespecified, RCS randomly selects subjects from the treatment-inclined subpopulation into the treatment arm and those from the control-inclined into the control arm. Samples in each arm are represe...

journal_title：Statistics in medicine

authors： Hu Z,Qin J

更新日期：2018-05-20 00:00:00

abstract：:Public health interventions are often designed to target communities defined either geographically (e.g. cities, counties) or socially (e.g. schools or workplaces). The group randomized trial (GRT) is regarded as the gold standard for evaluating these interventions. However, community leaders may object to randomizati...

journal_title：Statistics in medicine

authors： Pennell ML,Hade EM,Murray DM,Rhoda DA

更新日期：2011-07-10 00:00:00

abstract：:Laboratory determinations on children aged 6 to 10 years obtained over a 5-year period are analysed by a method described in detail for differentiating between children from exposed and control areas of Seveso, Italy. In the analysis, stratification is employed to distinguish the separate days of laboratory measuremen...

journal_title：Statistics in medicine

authors： Mantel N,Mocarelli P,Marocchi A,Brambilla P,Baretta R

更新日期：1983-04-01 00:00:00

abstract：:One is often interested in the ratio of two variables, for example in genetics, assessing drug effectiveness, and in health economics. In this paper, we derive an explicit geometric solution to the general problem of identifying the two tangents from an arbitrary external point to an ellipse. This solution permits num...

journal_title：Statistics in medicine

authors： Walter SD,Gafni A,Birch S

更新日期：2008-12-10 00:00:00

abstract：:Screening and diagnostic tests are important in disease prevention or control. The predictive values of positive and negative (PPV and NPV) test results are two of four operational characteristics of a screening test. We review an existing method based on the generalized estimating equation (GEE) methodology for compa...

journal_title：Statistics in medicine

authors： Wang W,Davis CS,Soong SJ

更新日期：2006-07-15 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：: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：:In multivariate network meta-analysis (NMA), the piecemeal nature of the evidence base means that there may be treatment-outcome combinations for which no data is available. Most existing multivariate evidence synthesis models are either unable to estimate the missing treatment-outcome combinations, or can only do so ...

journal_title：Statistics in medicine

authors： Waddingham E,Matthews PM,Ashby D

更新日期：2020-10-30 00:00:00