Sample size determination for testing equality in a cluster randomized trial with noncompliance.

abstract：:In a clinical dose finding study with active control a new drug with several dose levels is compared with an active comparator drug. The main focus of such studies often lies on the estimation of a target dose that leads to the same efficacy as the control. This article investigates the finite sample properties of the...

journal_title：Journal of biopharmaceutical statistics

authors： Helms HJ,Benda N,Friede T

更新日期：2015-01-01 00:00:00

abstract：:In this article, we show how to estimate a transition period for the evolvement of drug resistance to antiretroviral (ARV) drug or other related treatments in the framework of developing a Bayesian method for jointly analyzing time-to-event and longitudinal data. For HIV/AIDS longitudinal data, developmental trajector...

journal_title：Journal of biopharmaceutical statistics

authors： Dagne GA

更新日期：2018-01-01 00:00:00

abstract：:The Wilcoxon-Mann-Whitney (WMW) test is the most commonly used nonparametric method to compare two treatments when the underlying distribution of the outcome variable is not normally distributed. In the presence of stratum effects, the van Elteren (vE) test, a stratified WMW test, can be used to adjust for the stratum...

journal_title：Journal of biopharmaceutical statistics

authors： Qu Y,Zhao YD,Rahardja D

更新日期：2008-01-01 00:00:00

abstract：:Recently, a design was proposed for the Simultaneous Global Drug Development Program (SGDDP) to assess the impact of ethnic factors on the effect of a new treatment for a targeted ethnic (TE) population. It used weighted Z tests to combine the information collected from the TE and non-TE (NTE) subgroups in the SGDDP b...

journal_title：Journal of biopharmaceutical statistics

authors： Liu K,Yuan Z,Chen G,Huang Q,Wenrich J

更新日期：2015-01-01 00:00:00

abstract：:The Log-odds ratio for 2 × 2 contingency tables is often approximated by a normal distribution with an approximated variance. Hwang and Biswas (2008) illustrated that the standard expression for the variance should be modified in the presence of correlation. They also provided an adjustment to this variance expression...

journal_title：Journal of biopharmaceutical statistics

authors： Biswas A,Hwang JS

更新日期：2011-01-01 00:00:00

abstract：:Testing for noninferiority and equivalence between an experimental therapy and a standard therapy in terms of the ratio of binomial proportions is considered. New tests based on the Fieller-Hinkley distribution of the ratio of random variables are proposed. Restricted maximum likelihood estimates of the null variances...

journal_title：Journal of biopharmaceutical statistics

authors： Koti KM

更新日期：2007-01-01 00:00:00

abstract：:A mathematical model is described for selecting combinations of chemotherapeutic drugs in order to maximize antitumor dose intensity subject to constraints on toxicity to normal organ systems. Determination of which drugs to combine and in what proportions to combine them offers combinatorially huge numbers of possibi...

journal_title：Journal of biopharmaceutical statistics

authors： Simon R,Korn EL

更新日期：1991-01-01 00:00:00

abstract：:We propose a new adaptive threshold detection and enrichment design in which the biomarker threshold is adaptively estimated and updated by optimizing a trade-off between the size of the biomarker positive population and the magnitude of the treatment effect in that population. Enrichment is based on an enrollment cri...

journal_title：Journal of biopharmaceutical statistics

authors： Wang T,Wang X,George SL,Zhou H

更新日期：2020-11-11 00:00:00

abstract：:There is no consensus on determination of sample size in phase II clinical trials. The use of Bayesian decision theory has been proposed by Stallard (1), among others. In this article, optimal three-stage designs are obtained using decision theory. These are compared with procedures proposed by Schoenfeld (2), Ensign ...

journal_title：Journal of biopharmaceutical statistics

authors： Stallard N

更新日期：1998-07-01 00:00:00

abstract：:For approval of generic drugs, the U.S. Food and Drug Administration (FDA) requires the evidence of bioequivalence in average bioavailability be provided. This is based on the Fundmental Bioequivalence Assumption from FDA that if two drug products are shown to be bioequivalent, it is assumed that they are therapeutica...

journal_title：Journal of biopharmaceutical statistics

authors： Lu Y,Zhang ZZ,Chow SC

更新日期：2014-01-01 00:00:00

abstract：:An important application of confirmatory adaptive designs is the data-driven selection of treatment arms in multi-armed trials. A general methodology for adaptive designs is based on the combination testing principle. Using this principle, selection of treatment arms in multi-armed designs, recalculation of sample siz...

journal_title：Journal of biopharmaceutical statistics

authors： Wassmer G

更新日期：2011-07-01 00:00:00

abstract：:All too often in clinical trials the assessment of quality of life is seen as a bolt-on study. Consequently insufficient consideration is often given to its design, collection, analysis and presentation, and its impact on the trial results and on clinical practice is minimal. In many trials quality of life is a key en...

journal_title：Journal of biopharmaceutical statistics

authors： Stephens R

更新日期：2004-02-01 00:00:00

abstract：:Laboratory data with a lower quantification limit (censored data) are sometimes analyzed by replacing non-quantifiable values with a single value equal to or less than the quantification limit, yielding possibly biased point estimates and variance estimates that are too small. Motivated by a three-period, three-treatm...

journal_title：Journal of biopharmaceutical statistics

authors： Karon JM,Wiegand RE,van de Wijgert JH,Kilmarx PH

更新日期：2015-01-01 00:00:00

abstract：:As more biologic products are going off patent protection, the development of follow-on biologic products (also known as biosimilars) has gained much attention from both the biotechnology industry and regulatory agencies. Unlike small molecules, the development of biologic products is not only more complicated but als...

journal_title：Journal of biopharmaceutical statistics

authors： Zhang N,Yang J,Chow SC,Chi E

更新日期：2014-01-01 00:00:00

abstract：:The concept of quality by design (QbD) as published in ICH-Q8 is currently one of the most recurrent topics in the pharmaceutical literature. This guideline recommends the use of information and prior knowledge gathered during pharmaceutical development studies to provide a scientific rationale for the manufacturing p...

journal_title：Journal of biopharmaceutical statistics

authors： Lebrun P,Giacoletti K,Scherder T,Rozet E,Boulanger B

更新日期：2015-01-01 00:00:00

abstract：:Bowker's test, a generalization of McNemar's test, performs well under the hypothesis of symmetry, but the estimator of variance used in the test is biased when the table is asymmetric and this calls into question the test's performance in non-null situations. We seek an alternative to Bowker's test in search of metho...

journal_title：Journal of biopharmaceutical statistics

authors： May WL,Johnson WD

更新日期：2001-02-01 00:00:00

abstract：:With the use of finite mixture models for the clustering of a data set, the crucial question of how many clusters there are in the data can be addressed by testing for the smallest number of components in the mixture model compatible with the data. We investigate the performance of a resampling approach to this latter...

journal_title：Journal of biopharmaceutical statistics

authors： McLachlan GJ,Rathnayake SI

更新日期：2011-11-01 00:00:00

abstract：:We evaluate properties of sample size re-estimation (SSR) designs similar to the promising zone design considered by Mehta and Pocock (2011). We evaluate these designs under the assumption of a true effect size of 1.1 down to 0.4 of the protocol-specified effect size by six measures: 1. The probability of a sample siz...

journal_title：Journal of biopharmaceutical statistics

authors： Gaffney M,Ware JH

更新日期：2017-01-01 00:00:00

abstract：:People exposed to certain diseases are required to be treated with a safe and effective dose level of a drug. In epidemiological studies to find out an effective dose level, different dose levels are applied to the exposed and a certain number of cures is observed. Negative binomial distribution is considered to fit o...

journal_title：Journal of biopharmaceutical statistics

authors： Roy M,Choudhury K,Islam MM,Matin MA

更新日期：2013-01-01 00:00:00

abstract：:In recent years, development of biosimilar products has attracted considerable attention. Because of the structural complexity of biologics, it is difficult to demonstrate that a biosimilar product is identical to the reference product. Therefore, for the development of biosimilar products, we need to adopt an approac...

journal_title：Journal of biopharmaceutical statistics

authors： Nagasaki M,Ando Y

更新日期：2014-01-01 00:00:00

abstract：:For noninferiority testing with the maximum allowable noninferiority margin being prespecified, one can perform valid statistical testing at the same alpha level for multiple noninferiority hypotheses with margins being smaller than this maximum margin. This is easily comprehensible because only one confidence level i...

journal_title：Journal of biopharmaceutical statistics

authors： Hung HM,Wang SJ

更新日期：2004-05-01 00:00:00

abstract：:Large sample size imbalance is not uncommon in the biosimilar development. At the beginning of a product development, sample sizes of a biosimilar and a reference product may be limited. Thus, a sample size calculation may not be feasible. During the development stage, more batches of reference products may be added a...

journal_title：Journal of biopharmaceutical statistics

authors： Dong XC,Weng YT,Tsong Y

更新日期：2017-01-01 00:00:00

abstract：:An ability to predict the metabolic fate of a drug is important to drug design. Programs for predicting drug metabolites are becoming available, as are databases that will facilitate the development of such programs. Objective analysis of the performance of these programs will require statistical methods. The developm...

journal_title：Journal of biopharmaceutical statistics

authors： Johnson M

更新日期：1991-01-01 00:00:00

abstract：:The adverse events data of randomized clinical trials are often analyzed based on either crude incidence rates or exposure-adjusted incidence rates. These rates do not adequately account for an individual patient's profile of adverse events over the study period when an individual may remain in the trial after experie...

journal_title：Journal of biopharmaceutical statistics

authors： Siddiqui O

更新日期：2009-09-01 00:00:00

abstract：:Nonparametric versions of normal theory step-down multiple-test procedures for inferring minimum effective dose (see Tamhane et al. (1)) were developed and studied by Monte Carlo simulation. Two types of step-down testing procedures were examined. For both procedures, pairwise, linear, or Helmert contrasts of mean ran...

journal_title：Journal of biopharmaceutical statistics

authors： Sidik K,Morris RW

更新日期：1999-05-01 00:00:00

abstract：:We study the statistical efficiency for rising-dose designs in the context of first-in-human studies. Specifically, we identify a class of crossover designs that are appealing in terms of both subject safety and statistical efficiency and, for a three-period, two-panel design in such a class, we compare its A-efficien...

journal_title：Journal of biopharmaceutical statistics

authors： Yan Z,Hosmane B,Locke C

更新日期：2013-01-01 00:00:00

abstract：:In many clinical trials for chronic conditions a run-in period is used prior to randomization. Often, only those participants who meet certain criteria during the run-in phase go on to get randomized. The others, along with the information that they might have provided, are excluded from the study. This exclusion of t...

journal_title：Journal of biopharmaceutical statistics

authors： Berger VW,Vali B

更新日期：2011-03-01 00:00:00

abstract：:In the era of precision medicine, drugs are increasingly developed to target subgroups of patients with certain biomarkers. In large all-comer trials using a biomarker stratified design, the cost of treating and following patients for clinical outcomes may be prohibitive. With a fixed number of randomized patients, th...

journal_title：Journal of biopharmaceutical statistics

authors： Wang X,Zhou J,Wang T,George SL

更新日期：2018-01-01 00:00:00

abstract：:Noninferiority multiregional clinical trials (MRCTs) have recently received increasing attention in drug development. While a major goal in an MRCT is to estimate the global treatment effect, it is also important to assess the consistency of treatment effects across multiple regions. In this paper, we propose an intui...

journal_title：Journal of biopharmaceutical statistics

authors： Diao G,Zeng D,Ibrahim JG,Rong A,Lee O,Zhang K,Chen Q

更新日期：2017-01-01 00:00:00

abstract：:Highly clustered count data are commonly seen in medical device clinical studies such as cardiac rhythm management. For instance, anti-arrhythmia shocks delivered from an implantable cardioverter-defibrillator (ICD) often occur as "storms", i.e., multiple shocks within a short period of time. There are unique challeng...

journal_title：Journal of biopharmaceutical statistics

authors： Wang ZJ

更新日期：2008-01-01 00:00:00