Medical registers as historical controls: analysis of an open clinical trial of inosiplex in subacute sclerosing panencephalitis.

abstract：:Parameters for latent transition analysis (LTA) are easily estimated by maximum likelihood (ML) or Bayesian method via Markov chain Monte Carlo (MCMC). However, unusual features in the likelihood can cause difficulties in ML and Bayesian inference and estimation, especially with small samples. In this study we explore...

journal_title：Statistics in medicine

authors： Chung H,Lanza ST,Loken E

更新日期：2008-05-20 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：:Appropriate quantification of added usefulness offered by new markers included in risk prediction algorithms is a problem of active research and debate. Standard methods, including statistical significance and c statistic are useful but not sufficient. Net reclassification improvement (NRI) offers a simple intuitive w...

journal_title：Statistics in medicine

authors： Pencina MJ,D'Agostino RB Sr,Steyerberg EW

更新日期：2011-01-15 00:00:00

abstract：:Genome-wide association studies are characterized by a huge number of statistical tests performed to discover new disease-related genetic variants [in the form of single-nucleotide polymorphisms (SNPs)] in human DNA. Many SNPs have been identified for cross-sectionally measured phenotypes. However, there is a growing ...

journal_title：Statistics in medicine

authors： Sikorska K,Rivadeneira F,Groenen PJ,Hofman A,Uitterlinden AG,Eilers PH,Lesaffre E

更新日期：2013-01-15 00:00:00

abstract：:We simulated multinomial AIDS incidence counts from 27 'representative' AIDS epidemics that spanned a period corresponding to previous applications of backcalculation (1 January 1977 to 1 July 1987) and assessed mean square error for several back-calculated estimators of HIV prevalence and short-term AIDS projections....

journal_title：Statistics in medicine

authors： Rosenberg PS,Gail MH,Pee D

更新日期：1991-08-01 00:00:00

abstract：:We present an estimate of the kappa-coefficient of agreement between two methods of rating based on matched pairs of binary responses and show that the estimate depends on the common intraclass correlation coefficient between the pairs. Via Monte Carlo simulation, we investigate power of the test of significance on ka...

journal_title：Statistics in medicine

authors： Shoukri MM,Martin SW,Mian IU

更新日期：1995-01-15 00:00:00

abstract：:Several large-sample confidence intervals for the ratio of independent binomial proportions are compared in terms of exact coverage probability and width. A non-iterative approximate Bayesian interval is derived and its frequency properties are superior to all of the non-iterative confidence intervals considered. The ...

journal_title：Statistics in medicine

authors： Price RM,Bonett DG

更新日期：2008-11-20 00:00:00

abstract：:Correlation analysis is widely used in biomedical and psychosocial research for assessing rater reliability, precision of diagnosis and accuracy of proxy outcomes. The popularity of longitudinal study designs has propelled the proliferation in recent years of new methods for longitudinal and other multi-level clustere...

journal_title：Statistics in medicine

authors： Tu XM,Feng C,Kowalski J,Tang W,Wang H,Wan C,Ma Y

更新日期：2007-09-30 00:00:00

abstract：:In a medical study we are often interested in graphically displaying the relationship between continuous variables and clinical events indicating disease progression. Often, it is reasonable to make the minimal assumption that the risk of progression is an arbitrary monotone function of the continuous variable. Someti...

journal_title：Statistics in medicine

authors： Ancukiewicz M,Finkelstein DM,Schoenfeld DA

更新日期：2003-10-30 00:00:00

abstract：:For the meta-analysis of controlled clinical trials or epidemiological studies, in which the responses are at least approximately normally distributed, a refined test for the hypothesis of no overall treatment effect is proposed. The test statistic is based on a direct estimation function for the variance of the overa...

journal_title：Statistics in medicine

authors： Hartung J,Knapp G

更新日期：2001-06-30 00:00:00

abstract：:Mediation analysis is a standard approach to understanding how and why an intervention works in social and medical sciences. However, the presence of missing data, especially missing not at random data, poses a great challenge for the applicability of this approach in practice. Current methods for handling such missin...

journal_title：Statistics in medicine

authors： Li W,Zhou XH

更新日期：2017-11-10 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：: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：:Reference ranges which take time (such as age) into account are often required in medicine, but simple, systematic and efficient statistical methods for constructing them are lacking. A method is described which is based on low order polynomial curves (linear, quadratic or occasionally cubic), together with guidelines...

journal_title：Statistics in medicine

authors： Royston P

更新日期：1991-05-01 00:00:00

abstract：:Predicting an individual's risk of experiencing a future clinical outcome is a statistical task with important consequences for both practicing clinicians and public health experts. Modern observational databases such as electronic health records provide an alternative to the longitudinal cohort studies traditionally ...

journal_title：Statistics in medicine

authors： Wolfson J,Bandyopadhyay S,Elidrisi M,Vazquez-Benitez G,Vock DM,Musgrove D,Adomavicius G,Johnson PE,O'Connor PJ

更新日期：2015-09-20 00:00:00

abstract：:The asymptotic Pearson's chi-squared test and Fisher's exact test have long been the most used for testing association in 2x2 tables. Unconditional tests preserve the significance level and generally are more powerful than Fisher's exact test for moderate to small samples, but previously were disadvantaged by being co...

journal_title：Statistics in medicine

authors： Lydersen S,Fagerland MW,Laake P

更新日期：2009-03-30 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：:Methods for multiple informants help to estimate the marginal effect of each multiple source predictor and formally compare the strength of their association with an outcome. We extend multiple informant methods to the case of hierarchical data structures to account for within cluster correlation. We apply the propose...

journal_title：Statistics in medicine

authors： Baek J,Sánchez BN,Sanchez-Vaznaugh EV

更新日期：2014-02-20 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：:We investigate a binary partitioning algorithm in the case of a continuous repeated measures outcome. The procedure is based on the use of the likelihood ratio statistic to evaluate the performance of individual splits. The procedure partitions a set of longitudinal data into two mutually exclusive groups based on an ...

journal_title：Statistics in medicine

authors： Abdolell M,LeBlanc M,Stephens D,Harrison RV

更新日期：2002-11-30 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：:Comparative calibration is the broad statistical methodology used to assess the calibration of a set of p instruments, each designed to measure the same characteristic, on a common group of individuals. Different from the usual calibration problem, the true underlying quantity measured is unobservable. Many authors ha...

journal_title：Statistics in medicine

authors： Lu Y,Ye K,Mathur AK,Hui S,Fuerst TP,Genant HK

更新日期：1997-08-30 00:00:00

abstract：:Disease incidence or disease mortality rates for small areas are often displayed on maps. Maps of raw rates, disease counts divided by the total population at risk, have been criticized as unreliable due to non-constant variance associated with heterogeneity in base population size. This has led to the use of model-ba...

journal_title：Statistics in medicine

authors： Stern HS,Cressie N

更新日期：2000-09-15 00:00:00

abstract：:An observed confidence distribution is proposed as a measure of strength of evidence for practically equivalent efficacies of two treatments. The concept is independent of prior opinions about relevant sizes of a difference in efficacy. It also avoids retrospective power calculations for trials with missed recruitment...

journal_title：Statistics in medicine

authors： Mau J

更新日期：1988-12-01 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：:In longitudinal studies with incomplete data, where the number of time points can become numerous, it is often advantageous to model the covariance matrix. We describe several covariance models (for example, mixed models, compound symmetry, AR(1)-type models, and combination models) that offer parsimonious alternative...

journal_title：Statistics in medicine

authors： Grady JJ,Helms RW

更新日期：1995-07-15 00:00:00

abstract：:Identification of key factors associated with the risk of developing cardiovascular disease and quantification of this risk using multivariable prediction algorithms are among the major advances made in preventive cardiology and cardiovascular epidemiology in the 20th century. The ongoing discovery of new risk markers...

journal_title：Statistics in medicine

authors： Pencina MJ,D'Agostino RB Sr,D'Agostino RB Jr,Vasan RS

更新日期：2008-01-30 00:00:00

abstract：:The focus of this paper is the development of a range of cluster detection diagnostics that can be used to assess the degree to which a clustering method recovers the true clustering behaviour of small area data. The diagnostics proposed range from individual region specific diagnostics to neighbourhood diagnostics, a...

journal_title：Statistics in medicine

authors： Hossain MM,Lawson AB

更新日期：2006-03-15 00:00:00

abstract：:Missing data arise in crossover trials, as they do in any form of clinical trial. Several papers have addressed the problems that missing data create, although almost all of these assume that the probability that a planned observation is missing does not depend on the value that would have been observed; that is, the ...

journal_title：Statistics in medicine

authors： Ho WK,Matthews JN,Henderson R,Farewell D,Rodgers LR

更新日期：2012-07-20 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