The analysis of incomplete data in the three-period two-treatment cross-over design for clinical trials.

abstract：:A new method is proposed for the surveillance of Down's syndrome among newborn. Despite the strong dependence of overall risk of Down's syndrome on maternal age, it has been suggested that an environmentally induced increase in risk may be additive over all maternal ages. The surveillance method introduced here is spe...

journal_title：Statistics in medicine

authors： Lie RT,Heuch I,Irgens LM

更新日期：1993-01-15 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：:Many extensions of survival models based on the Cox proportional hazards approach have been proposed to handle clustered or multiple event data. Of particular note are five Cox-based models for recurrent event data: Andersen and Gill (AG); Wei, Lin and Weissfeld (WLW); Prentice, Williams and Peterson, total time (PWP-...

journal_title：Statistics in medicine

authors： Kelly PJ,Lim LL

更新日期：2000-01-15 00:00:00

abstract：:In England and Wales, a large-scale multiple statistical surveillance system for infectious disease outbreaks has been in operation for nearly two decades. This system uses a robust quasi-Poisson regression algorithm to identify abberrances in weekly counts of isolates reported to the Health Protection Agency. In this...

journal_title：Statistics in medicine

authors： Noufaily A,Enki DG,Farrington P,Garthwaite P,Andrews N,Charlett A

更新日期：2013-03-30 00:00:00

abstract：:In biomedical research such as the development of vaccines for infectious diseases or cancer, study outcomes measured by an assay or device are often collected from multiple sources or laboratories. Measurement error that may vary between laboratories needs to be adjusted for when combining samples across data sources...

journal_title：Statistics in medicine

authors： Huang Y,Huang Y,Moodie Z,Li S,Self S

更新日期：2012-12-10 00:00:00

abstract：:R2 has been criticized as a measure of model performance when predicting a dichotomous outcome, both because its value is often low and because it is sensitive to the prevalence of the event of interest. The C statistic is more widely used to measure model performance in a 0/1 setting. We use a simple parametric famil...

journal_title：Statistics in medicine

authors： Ash A,Shwartz M

更新日期：1999-02-28 00:00:00

abstract：:Comparative Poisson trials of prophylactic interventions, such as vaccines, can be lengthy and costly. We evaluate two easily implemented approaches to reduce numbers of disease cases and person years of follow up (N(u+t)) for comparative Poisson trials with fixed numbers of cases (T); (i) altering k the portion of N(...

journal_title：Statistics in medicine

authors： Hoover DR

更新日期：2004-04-30 00:00:00

abstract：:Meta-analysis has generally been accepted as a fundamental tool for combining effect estimates from several studies. For binary studies with rare events, the Peto odds ratio (POR) method has become the relative effect estimator of choice. However, the POR leads to biased estimates for the OR when treatment effects are...

journal_title：Statistics in medicine

authors： Brockhaus AC,Bender R,Skipka G

更新日期：2014-12-10 00:00:00

abstract：:Hypothesis testing, in which the null hypothesis specifies no difference between treatment groups, is an important tool in the assessment of new medical interventions. For randomized clinical trials, permutation tests that reflect the actual randomization are design-based analyses for such hypotheses. This means that ...

journal_title：Statistics in medicine

authors： Berger VW

更新日期：2000-05-30 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：:In behavioral, biomedical, and social-psychological sciences, it is common to encounter latent variables and heterogeneous data. Mixture structural equation models (SEMs) are very useful methods to analyze these kinds of data. Moreover, the presence of missing data, including both missing responses and missing covaria...

journal_title：Statistics in medicine

authors： Cai JH,Song XY,Hser YI

更新日期：2010-08-15 00:00:00

abstract：:Phase II trials often test the null hypothesis H(0): p or=p(1), where p is the true unknown proportion responding to the new treatment, p(0) is the greatest response proportion which is deemed clinically ineffective, and p(1) is the smallest response proportion which is deemed clinically effe...

journal_title：Statistics in medicine

authors： Ayanlowo AO,Redden DT

更新日期：2007-03-30 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：:We examine Goodman and Kruskal's lambda using Efron's approach to regression and analysis of variance (ANOVA) for zero-one outcome data. For a binary response cross-classified by a single nominal predictor, we present a computationally simple ANOVA table in which lambda is analogous to Pearson's R-square. We character...

journal_title：Statistics in medicine

authors： Makuch RW,Rosenberg PS,Scott G

更新日期：1989-05-01 00:00:00

abstract：:The FDA permits marketing of a generic formulation of a drug G for the same indications as a standard preparation S if one can show that G is bioequivalent to S. Present implementation requires convincing evidence that the population mean difference in bioavailability (drug exposure) between the two preparations lies ...

journal_title：Statistics in medicine

authors： Sheiner LB

更新日期：1992-09-30 00:00:00

abstract：:We propose a probability distribution for an equivalence class of classification trees (that is, those that ignore the value of the cutpoints but retain tree structure). This distribution is parameterized by a central tree structure representing the true model, and a precision or concentration coefficient representing...

journal_title：Statistics in medicine

authors： Shannon WD,Banks D

更新日期：1999-03-30 00:00:00

abstract：:Members of a cohort of workers in chemical industry (the so-called Boehringer cohort) exposed to 2, 3, 7, 8-tetrachlorodibenzo-para-dioxin (TCDD) from 1950 to 1984 were subject in the years 1985-1986 and 1992-1994 to an extensive biomonitoring programme on the TCDD levels of the individual workers. For establishing a ...

journal_title：Statistics in medicine

authors： Heinzl H,Mittlböck M,Edler L

更新日期：2008-05-30 00:00:00

abstract：:The lifetime risk of a clinical condition is the probability of onset of the condition during one's lifespan. Recent advances in Alzheimer's disease (AD) research have identified screening tests for biomarkers that can identify persons who are in the earliest stages of the AD process but who do not yet have any clinic...

journal_title：Statistics in medicine

authors： Brookmeyer R,Abdalla N

更新日期：2019-04-30 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：:This paper gives a standard error for Cohen's Kappa, conditional on the margins of the observed r x r table. An explicit formula is given for the 2 x 2 table, and a procedure for the more general situation. A parsimonious log-linear model is suggested for the general case and an approximate confidence interval for kap...

journal_title：Statistics in medicine

authors： Garner JB

更新日期：1991-05-01 00:00:00

abstract：:Interim analyses are conducted to allow for early termination of the trial, for ethical as well as economical reasons. Here we consider interim analyses in repeated measurements studies where the measurements are binary. Two methods for analysing this kind of data are compared according to their operating characterist...

journal_title：Statistics in medicine

authors： Spiessens B,Lesaffre E,Verbeke G

更新日期：2003-02-28 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：:The recent revision of the Declaration of Helsinki and the existence of many new therapies that affect survival or serious morbidity, and that therefore cannot be denied patients, have generated increased interest in active-control trials, particularly those intended to show equivalence or non-inferiority to the activ...

journal_title：Statistics in medicine

authors： Rothmann M,Li N,Chen G,Chi GY,Temple R,Tsou HH

更新日期：2003-01-30 00:00:00

abstract：:Although statistical methodology is well-developed for comparing diagnostic tests in terms of their sensitivity and specificity, comparative inference about predictive values is not. In this paper, we consider the analysis of studies comparing operating characteristics of two diagnostic tests that are measured on all ...

journal_title：Statistics in medicine

authors： Kwak M,Um SW,Jung SH

更新日期：2015-07-10 00:00:00

abstract：:Growth trends in children are often based on cross-sectional studies, in which a sample of the population is investigated at one given point in time. Estimating age-related percentiles in such studies involves fitting data distributions, each of which is specific for one age group, and a subsequent smoothing of the pe...

journal_title：Statistics in medicine

authors： Sorribas A,March J,Voit EO

更新日期：2000-03-15 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 different fields of applications including, but not limited to, behavioral, environmental, medical sciences, and econometrics, the use of panel data regression models has become increasingly popular as a general framework for making meaningful statistical inferences. However, when the ordinary least squares (OLS) m...

journal_title：Statistics in medicine

authors： Hamiye Beyaztas B,Bandyopadhyay S

更新日期：2020-12-20 00:00:00

abstract：:The relationship between association and surrogacy has been the focus of much debate in the surrogate marker literature. Recently, the individual causal association (ICA) has been introduced as a metric of surrogacy in the causal inference framework, when both the surrogate and the true endpoint are normally distribut...

journal_title：Statistics in medicine

authors： Meyvisch P,Alonso A,Van der Elst W,Molenberghs G

更新日期：2020-11-20 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：:In contrast to other models for ordinal data, the continuation ratio model can be fitted with standard statistical software. This makes it particularly appropriate for large clinical trials with ordinal response variables. In addition, when the trials are longitudinal, this model can be applied to individual responses...

journal_title：Statistics in medicine

authors： Lindsey JK,Jones B,Ebbutt AF

更新日期：1997-12-30 00:00:00