Evaluation of discordance measures in oncology studies with blinded independent central review of progression-free survival using an observational error model.

abstract：:Ratio of means (ROM) and difference of means (DOM) are often used in a superiority, noninferiority (NI), or average bioequivalence (ABE) test to evaluate whether the test mean is superior, NI, or equivalent to the reference (placebo or active control) mean. The literature provides recommendations regarding how to choo...

journal_title：Journal of biopharmaceutical statistics

authors： Sun W,Grosser S,Tsong Y

更新日期：2017-01-01 00:00:00

abstract：:We extend the development of the expression of the Fisher information matrix in nonlinear mixed effects models for designs evaluation. We consider the dependence of the marginal variance of the observations with the mean parameters and assume an heteroscedastic variance error model. Complex models with interoccasions ...

journal_title：Journal of biopharmaceutical statistics

authors： Retout S,Mentré F

更新日期：2003-05-01 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：:In method comparison and reliability studies, it is often important to assess agreement between multiple measurements made by different methods, devices, laboratories, observers, or instruments. For continuous data, the concordance correlation coefficient (CCC) is a popular index for assessing agreement between multip...

journal_title：Journal of biopharmaceutical statistics

authors： Barnhart HX,Lokhnygina Y,Kosinski AS,Haber M

更新日期：2007-01-01 00:00:00

abstract：:I review the designs available for Phase I dose-finding studies of chemotherapeutic agents in cancer patients. The designs are based on the assumption that both efficacy and toxicity increase with dose, and thus attempt to minimize the number of patients treated at low doses, and also to minimize the chance that patie...

journal_title：Journal of biopharmaceutical statistics

authors： Potter DM

更新日期：2006-01-01 00:00:00

abstract：:The aim of this work is to quantitatively assess the impact of structural model misspecifications on the estimates of mean and interindividual variability of clearance in the context of population approaches. This assessment is conducted from simulated datasets. Our results show that impact magnitude of model misspeci...

journal_title：Journal of biopharmaceutical statistics

authors： Merlé Y,Aouimer A,Tod M

更新日期：2004-02-01 00:00:00

abstract：:Sample size calculation formulas for testing equality, noninferiority, superiority, and equivalence based on odds ratio were derived under both parallel and one-arm crossover designs. An example concerning the study of odds ratio between a test compound (treatment) and a standard therapy (control) for prevention of re...

journal_title：Journal of biopharmaceutical statistics

authors： Wang H,Chow SC,Li G

更新日期：2002-11-01 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：:The sequential parallel comparison design (SPCD) is a two-stage design recommended for trials with possibly high placebo response. A drug-placebo comparison in the first stage is followed in the second stage by placebo nonresponders being re-randomized between drug and placebo. We describe how SPCD can be used in tria...

journal_title：Journal of biopharmaceutical statistics

authors： Wang JJ,Ivanova A

更新日期：2014-01-01 00:00:00

abstract：:The widely used distinction of Little and Rubin (1) about types of randomness for missing data presents difficulties in its application to dropouts in longitudinal repeated measurement studies. In its place, a new typology of randomness for dropouts is proposed that relies on using a survival model for the dropout pro...

journal_title：Journal of biopharmaceutical statistics

authors： Lindsey JK

更新日期：2000-11-01 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：:Recently, two CPMP Points to Consider, one on adjustment for baseline covariates and the other on multiplicity issues in clinical trials, have included recommendations on the use of subgroup analysis for regulatory purposes. However, despite their regular use and regulatory attention, the validity and nature of subgro...

journal_title：Journal of biopharmaceutical statistics

authors： Grouin JM,Coste M,Lewis J

更新日期：2005-01-01 00:00:00

abstract：:Bayesian decision procedures have already been proposed for and implemented in Phase I dose-escalation studies in healthy volunteers. The procedures have been based on pharmacokinetic responses reflecting the concentration of the drug in blood plasma and are conducted to learn about the dose-response relationship whil...

journal_title：Journal of biopharmaceutical statistics

authors： Whitehead J,Zhou Y,Hampson L,Ledent E,Pereira A

更新日期：2007-01-01 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：:The United States Pharmacopeia (USP) content uniformity sampling acceptance plan consisting of a two-stage sampling plan with criteria on sample mean and number of out-of-range tablets is the standard for compendium. It is, however, often used mistakenly for lot quality assurance. In comparison to the Japan Phamacopei...

journal_title：Journal of biopharmaceutical statistics

authors： Tsong Y,Shen M

更新日期：2007-01-01 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 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：:Sample size estimation (SSE) is an important issue in the planning of clinical studies. While larger studies are likely to have sufficient power, it may be unethical to expose more patients than necessary to answer a scientific question. Budget considerations may also cause one to limit the study to an adequate size t...

journal_title：Journal of biopharmaceutical statistics

authors： Wu PS,Lin M,Chow SC

更新日期：2016-01-01 00:00:00

abstract：:We assess the QT effect using an exposure-response model in a "thorough QT/QTc study" with a four-period crossover design in which the treatments are placebo, positive control, higher dose of investigational drug, and therapeutic dose of investigational drug. In the study, QTc interval values and the drug concentratio...

journal_title：Journal of biopharmaceutical statistics

authors： Hosmane B,Locke C,Chiu YL

更新日期：2010-05-01 00:00:00

abstract：:Stability testing is a procedure frequently used in the pharmaceutical industry to estimate the shelf life of a drug. Hereby, a standard problem of interest is whether or not to pool a given number of batches to assign a single shelf life for the combined batches. In this paper, we propose two modified methods for the...

journal_title：Journal of biopharmaceutical statistics

authors： Djira GD,Hothorn LA,Tsong Y

更新日期：2008-01-01 00:00:00

abstract：:A thorough QT trial is typically designed to test for two set of hypotheses. The primary set of hypotheses is for demonstrating that the test treatment will not prolong QT interval. The second set of hypotheses is to demonstrate the assay sensitivity of the positive control treatment in the study population. The conve...

journal_title：Journal of biopharmaceutical statistics

authors： Tsong Y

更新日期：2013-01-01 00:00:00

abstract：:An adaptive enrichment design is a randomized trial that allows enrollment criteria to be modified at interim analyses, based on a preset decision rule. When there is prior uncertainty regarding treatment effect heterogeneity, these trial designs can provide improved power for detecting treatment effects in subpopulat...

journal_title：Journal of biopharmaceutical statistics

authors： Fisher A,Rosenblum M,Alzheimer’s Disease Neuroimaging Initiative.

更新日期：2018-01-01 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：:We provide a set of formulas that allow the combination of separately performed analyses of population pharmacokinetic (PK) studies, without any further computational effort. More specifically, given the point estimates and uncertainties of two population PK analyses, the formulas provide the point estimates and uncer...

journal_title：Journal of biopharmaceutical statistics

authors： Dokoumetzidis A,Aarons L

更新日期：2008-01-01 00:00:00

abstract：:According to ICH Q6A (1999), a specification is defined as a list of tests, references to analytical procedures, and appropriate acceptance criteria, which are numerical limits, ranges, or other criteria for the tests described. For drug products, specifications usually consist of test methods and acceptance criteria ...

journal_title：Journal of biopharmaceutical statistics

authors： Dong X,Tsong Y,Shen M

更新日期：2015-01-01 00:00:00

abstract：:This paper addresses the problem of analyzing multivariate response with the variates having different distributions. We use the generalized estimating equations proposed by Prentice and Zhao (1) to estimate mean and covariance parameters. Wald statistics are used to test hypotheses about the parameters. Data from a t...

journal_title：Journal of biopharmaceutical statistics

authors： May WL,Johnson WD

更新日期：1996-05-01 00:00:00

abstract：:Fisher's exact test and Pearson's chi-square with continuity correction are frequently employed in the analysis of epidemiological data involving a 2 x 2 contingency table. This paper reviews the concepts and controversies underlying these procedures and discusses their appropriateness and adequacies in analyzing such...

journal_title：Journal of biopharmaceutical statistics

authors： Sahai H,Khurshid A

更新日期：1995-03-01 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 randomized, active-control clinical trial setting with the objective of testing noninferiority for a continuous response variable is considered. Noninferiority margin is based on the concept of preserving a certain fraction of the active control effect. Noninferiority is established if the ratio of the lower (upper)...

journal_title：Journal of biopharmaceutical statistics

authors： Chen M,Kianifard F,Dhar SK

更新日期：2006-05-01 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