Missing data and sensitivity analysis for binary data with implications for sample size and power of randomized clinical trials.

abstract：:The U.S. Food and Drug Administration (FDA) has proposed new regulations that address the 'prescribability' and 'switchability' of new formulations of already-approved drugs. These new criteria are known, respectively, as population and individual bioequivalence. Two methods have been proposed in the bioequivalence li...

journal_title：Statistics in medicine

authors： McNally RJ,Iyer H,Mathew T

更新日期：2003-01-15 00:00:00

abstract：:The log-rank test is the most powerful non-parametric test for detecting a proportional hazards alternative and thus is the most commonly used testing procedure for comparing time-to-event distributions between different treatments in clinical trials. When the log-rank test is used for the primary data analysis, the s...

journal_title：Statistics in medicine

authors： Zhang D,Quan H

更新日期：2009-02-28 00:00:00

abstract：:While there has been extensive research developing gene-environment interaction (GEI) methods in case-control studies, little attention has been given to sparse and efficient modeling of GEI in longitudinal studies. In a two-way table for GEI with rows and columns as categorical variables, a conventional saturated int...

journal_title：Statistics in medicine

authors： Ko YA,Mukherjee B,Smith JA,Park SK,Kardia SL,Allison MA,Vokonas PS,Chen J,Diez-Roux AV

更新日期：2014-12-20 00:00:00

abstract：:Conventional seamless phase 2/3 design with fixed sample size determination (SSD) has gained its popularity in oncology drug development due to attractive features such as significantly shortening the development timeline, minimizing sample size, as well as early decision making. However, this design is not immune to ...

journal_title：Statistics in medicine

authors： Teng Z,Tian Y,Liu Y,Liu G

更新日期：2020-08-15 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：:A preference trial is a special form of cross-over trial where clinical conditions determine when patients change treatment, in a prescribed order. This can be modelled using a geometric distribution. The model can be simply fitted using standard logistic regression methodology. The procedure is applied to a trial stu...

journal_title：Statistics in medicine

authors： Lindsey JK,Jones B

更新日期：1996-02-28 00:00:00

abstract：:In modern observational studies using electronic health records or other routinely collected data, both the outcome and covariates of interest can be error-prone and their errors often correlated. A cost-effective solution is the two-phase design, under which the error-prone outcome and covariates are observed for all...

journal_title：Statistics in medicine

authors： Tao R,Lotspeich SC,Amorim G,Shaw PA,Shepherd BE

更新日期：2021-02-10 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：: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：:Day and Walter derived methods of joint maximum likelihood estimation for the sojourn time distribution and the false negative rate for a screening programme. Their methods are not directly applicable to a programme which uses alternate screening by two modalities whose sojourn times and false negative rates will diff...

journal_title：Statistics in medicine

authors： Alexander FE

更新日期：1989-06-01 00:00:00

abstract：:A method has been developed for simultaneously comparing the usefulness of many treatments of established value for symptomatic medical conditions. Medical assessment of outcome is not employed. Instead patients are required to assess treatments prescribed during the course of ordinary general practice rather than und...

journal_title：Statistics in medicine

authors： Charlton JR,D'Souza MF,Tooley M,Silver R

更新日期：1985-01-01 00:00:00

abstract：:Assessment of quality of life is becoming standard in clinical trials. A popular method for measuring quality of life is with instruments which utilize multiple-item subscales, in which each item is scored on a Likert scale. Most statistical methods for the analysis of quality of life data in clinical trials do not ex...

journal_title：Statistics in medicine

authors： Douglas JA

更新日期：1999-11-15 00:00:00

abstract：:In a typical bioequivalence trial, summary measures of the plasma concentration versus time profile are used to compare two formulations of a drug product. Commonly used measures include area under the curve (AUC), maximum plasma concentration (C(max)) and time to maximum concentration (T(max)). Equivalence of these s...

journal_title：Statistics in medicine

authors： Mauger DT,Chinchilli VM

更新日期：2000-10-30 00:00:00

abstract：:The authors measure the efficacy of three methods for predicting the time to infection for susceptible individuals in a population undergoing an HIV epidemic. The methods differ in whether they require detailed information of the contact network and whether they require knowledge of the initial source of infection. Ef...

journal_title：Statistics in medicine

authors： Altmann M,Wee BC,Willard K,Peterson D,Gatewood LC

更新日期：1994-01-15 00:00:00

abstract：:Among many other uses, positron emission tomography (PET) can be used in studies to estimate the density of a neuroreceptor at each location throughout the brain by measuring the concentration of a radiotracer over time and modeling its kinetics. There are a variety of kinetic models in common usage and these typicall...

journal_title：Statistics in medicine

authors： Chang C,Ogden RT

更新日期：2009-03-15 00:00:00

abstract：:A trial of Duchenne muscular dystrophy involved tracking boys of all ages through a one-year baseline period, followed by a one-year trial of leucine versus placebo treatment. In this paper we develop a model for a total-muscle-strength score that uses the data of the extended baseline period in the evaluation of the ...

journal_title：Statistics in medicine

authors： Madsen KS,Miller JP,Province MA

更新日期：1986-05-01 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：:The Box-Cox power exponential (BCPE) distribution, developed in this paper, provides a model for a dependent variable Y exhibiting both skewness and kurtosis (leptokurtosis or platykurtosis). The distribution is defined by a power transformation Y(nu) having a shifted and scaled (truncated) standard power exponential ...

journal_title：Statistics in medicine

authors： Rigby RA,Stasinopoulos DM

更新日期：2004-10-15 00:00:00

abstract：:To study the effect of a mega hydropower dam in southwest Ethiopia on malaria incidence, we have set up a longitudinal study. To gain insight in temporal and spatial aspects, that is, in time (period  =  year-season combination) and location (village), we need models that account for these effects. The frailty model w...

journal_title：Statistics in medicine

authors： Getachew Y,Janssen P,Yewhalaw D,Speybroeck N,Duchateau L

更新日期：2013-08-15 00:00:00

abstract：:Binary classification rules based on covariates typically depend on simple loss functions such as zero-one misclassification. Some cases may require more complex loss functions. For example, individual-level monitoring of HIV-infected individuals on antiretroviral therapy requires periodic assessment of treatment fail...

journal_title：Statistics in medicine

authors： Xu Y,Liu T,Daniels MJ,Kantor R,Mwangi A,Hogan JW

更新日期：2019-05-20 00:00:00

abstract：:We present a method to determine the number of subjects, k, and number of repeated measurements, n, that minimize the overall cost of conducting a reliability study, while providing acceptable power for tests of hypotheses concerning the reliability coefficient rho. Tables showing optimal choices of k and n under vari...

journal_title：Statistics in medicine

authors： Eliasziw M,Donner A

更新日期：1987-09-01 00:00:00

abstract：:Sequential analysis is frequently employed to address ethical and financial issues in clinical trials. Sequential analysis may be performed using standard group sequential designs, or, more recently, with adaptive designs that use estimates of treatment effect to modify the maximal statistical information to be collec...

journal_title：Statistics in medicine

authors： Emerson SC,Rudser KD,Emerson SS

更新日期：2011-05-20 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 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：:Several relative risk models for survival time data in drug combination therapy are derived and their properties are discussed. The main intention of this paper is to clarify the differences among the models in order to help to choose the appropriate one in a given situation. The models are motivated by discussing the...

journal_title：Statistics in medicine

authors： Kübler J,Schumacher M

更新日期：1990-12-01 00:00:00

abstract：:When the event time of interest depends on the censoring time, conventional two-sample test methods, such as the log-rank and Wilcoxon tests, can produce an invalid test result. We extend our previous work on estimation using auxiliary variables to adjust for dependent censoring via multiple imputation, to the compari...

journal_title：Statistics in medicine

authors： Hsu CH,Taylor JM

更新日期：2009-02-01 00:00:00

abstract：:Some clinical trials aim to demonstrate therapeutic equivalence on multiple primary endpoints. For example, therapeutic equivalence studies of agents for the treatment of osteoarthritis use several primary endpoints including investigator's global assessment of disease activity, patient's global assessment of response...

journal_title：Statistics in medicine

authors： Quan H,Bolognese J,Yuan W

更新日期：2001-11-15 00:00:00

abstract：:This paper reviews Bayesian strategies for monitoring clinical trial data. It focuses on a Bayesian stochastic curtailment method based on the predictive probability of observing a clinically significant outcome at the scheduled end of the study given the observed data. The proposed method is applied to derive efficac...

journal_title：Statistics in medicine

authors： Dmitrienko A,Wang MD

更新日期：2006-07-15 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：: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