Measuring parallelism, linearity, and relative potency in bioassay and immunoassay data.

abstract：:Dichotomizing a continuous biomarker is a common practice in medical research. Various methods exist in the literature for dichotomizing continuous biomarkers. The most widely adopted minimum p-value approach uses a sequence of test statistics for all possible dichotomizations of a continuous biomarker, and it chooses...

journal_title：Journal of biopharmaceutical statistics

authors： Su M,Fang L,Su Z

更新日期：2013-05-01 00:00:00

abstract：:The aim of this article is to propose a multilevel combined model for repeated, hierarchical, and overdispersed time-to-event outcomes, extending the so-called combined model proposed by Molenberghs et al. (2010), and using three different estimation strategies: full likelihood, pseudo-likelihood, and Bayesian estimat...

journal_title：Journal of biopharmaceutical statistics

authors： Efendi A,Molenberghs G

更新日期：2013-01-01 00:00:00

abstract：:Patient-reported outcomes are important for assessing the effectiveness of treatments in many disease areas. For this reason, many new instruments that capture patient-reported outcomes have been developed over the past several decades. With the development of each new instrument, there is the ensuing question of what...

journal_title：Journal of biopharmaceutical statistics

authors： Kirby S,Chuang-Stein C,Morris M

更新日期：2010-09-01 00:00:00

abstract：:Investigating the prevalence of a disease is an important topic in medical studies. Such investigations are usually based on the classification results of a group of subjects according to whether they have the disease. To classify subjects, screening tests that are inexpensive and nonintrusive to the test subjects are...

journal_title：Journal of biopharmaceutical statistics

authors： Tang ML,Qiu SF,Poon WY,Tang NS

更新日期：2012-01-01 00:00:00

abstract：:Multiple testing problems in regulatory applications are often more challenging than the problems of handling a set of mathematical symbols representing multiple null hypotheses under testing. In the union-intersection setting, it is important to define a family of null hypotheses relevant to the clinical questions at...

journal_title：Journal of biopharmaceutical statistics

authors： Hung HM,Wang SJ

更新日期：2009-01-01 00:00:00

abstract：:In this paper I consider a problem of identifying all effective and superior drug combinations. I formulate this problem in terms of a family of hypotheses and propose a two-stage method to solve it. The first stage uses individual p-values obtained via the Min tests, whereas Holm's approach is employed in the second ...

journal_title：Journal of biopharmaceutical statistics

authors： Soulakova JN

更新日期：2009-01-01 00:00:00

abstract：:We studied the sensitivity of the number of unique design points and their placement, in Bayesian optimal designs for pharmacokinetic models, with respect to the magnitude of prior uncertainty. We used two and three-parameter pharmacokinetic models with fixed and mixed effects and two Bayesian optimal design criteria,...

journal_title：Journal of biopharmaceutical statistics

authors： Dokoumetzidis A,Aarons L

更新日期：2007-01-01 00:00:00

abstract：:A main challenge in molecular diagnostic research is to accurately evaluate the performance of a new nucleic acid amplification test when the reference standard is imperfect. Several approaches, such as discrepant analysis, composite reference standard (CRS) method, or latent class analysis (LCA), are commonly applied...

journal_title：Journal of biopharmaceutical statistics

authors： Tang S,Hemyari P,Canchola JA,Duncan J

更新日期：2018-01-01 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：:Receptor occupancy (RO) PET is a non-invasive way to determine drug on target. Given the complexity of procedures, long acquisition times, and high cost, ligand displacement imaging trials often have a limited size and produce sparse RO results over the time course of the blocking drug. To take the best advantage of t...

journal_title：Journal of biopharmaceutical statistics

authors： Vandenhende F,Renard D,Nie Y,Kumar A,Miller J,Tauscher J,Witcher J,Zhou Y,Wong DF

更新日期：2008-01-01 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：: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：:After a group sequential test, the naive confidence interval (CI) is usually biased in the sense that it does not cover the true parameter at the correct nominal level. Furthermore, when the stopping time is taken into account, the actual conditional confidence coverage probability can be much less accurate. In this a...

journal_title：Journal of biopharmaceutical statistics

authors： Fan X,DeMets DL

更新日期：2006-01-01 00:00:00

abstract：:Four multidose animal carcinogenicity assay trend test procedures based on the chi-square, Hoel-Walburg, log-rank, and Peto procedures are compared under conditions of competing risks. A total of 42 different risk populations are simulated in which a simulated animal can contract one or more of five different tumor ty...

journal_title：Journal of biopharmaceutical statistics

authors： Graves TS

更新日期：1994-11-01 00:00:00

abstract：:Group sequential methods to allow the possibility of early termination of a trial due to sufficiently convincing results are a standard in therapeutic clinical trials but have been little considered in bioequivalence trials. We investigate the statistical properties of one group sequential approach to bioequivalence t...

journal_title：Journal of biopharmaceutical statistics

authors： Hauck WW,Preston PE,Bois FY

更新日期：1997-03-01 00:00:00

abstract：:In literature, there are a few unified approaches to test proof of concept and estimate a target dose, including the multiple comparison procedure using modeling approach, and the permutation approach proposed by Klingenberg. We discuss and compare the operating characteristics of these unified approaches and further ...

journal_title：Journal of biopharmaceutical statistics

authors： Tang Y,Cai C,Sun L,He J

更新日期：2017-01-01 00:00:00

abstract：:Bayesian statistical methodology has been used for more than 10 years in medical device premarket submissions to the U.S. Food and Drug Administration (FDA). A complete list of the publicly available information associated with these FDA applications is presented. In addition to the increasing number of Bayesian metho...

journal_title：Journal of biopharmaceutical statistics

authors： Campbell G

更新日期：2011-09-01 00:00:00

abstract：:Gene expression profiling has played an important role in cancer risk classification and has shown promising results. Since gene expression profiling often involves determination of a set of top rank genes for analysis, it is important to evaluate how modeling performance varies with the number of selected top ranked ...

journal_title：Journal of biopharmaceutical statistics

authors： Chen DT,Schell MJ,Chen JJ,Fulp WJ,Eschrich S,Yeatman T

更新日期：2008-01-01 00:00:00

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：:The use of adaptive methods in clinical development has become very popular in recent years due to its flexibility in modifying trial procedures and/or statistical procedures of on-going clinical trials. Modifications to trial procedures are usually documented by protocol amendments. However, the actual patient popula...

journal_title：Journal of biopharmaceutical statistics

authors： Chow SC,Shao J

更新日期：2005-01-01 00:00:00

abstract：:In traditional dose-finding studies, dose-limiting toxicity (DLT) is determined within a fixed time observation window where DLT is often defined as a binary outcome. In the setting of oncology dose-finding trials, often patients in advanced stage of diseases are enrolled. Therefore, disease progression may occur with...

journal_title：Journal of biopharmaceutical statistics

authors： Biard L,Cheng B,Manji GA,Lee SM

更新日期：2020-09-15 00:00:00

abstract：:This article discusses the design of a clinical trial where a new treatment will be compared to a control. For a specific type of endpoint, there are a wide variety of test statistics that can be used. Also, the investigator must decide how many patients to accrue in each arm as well as the duration of the study. Afte...

journal_title：Journal of biopharmaceutical statistics

authors： Lawrence J

更新日期：2002-05-01 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：:Clinical trials with data-driven decision rules often pursue multiple clinical objectives such as the evaluation of several endpoints or several doses of an experimental treatment. These complex analysis strategies give rise to "multivariate" multiplicity problems with several components or sources of multiplicity. A ...

journal_title：Journal of biopharmaceutical statistics

authors： Kordzakhia G,Dmitrienko A,Ishida E

更新日期：2018-01-01 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：:In analytical similarity assessment of a biosimilar product, key quality attributes of the test and reference products need to be shown statistically similar. When there were multiple references, similarity among the reference products is also required. We proposed a simultaneous confidence approach based on the fiduc...

journal_title：Journal of biopharmaceutical statistics

authors： Zheng J,Yin D,Yuan M,Chow SC

更新日期：2019-01-01 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：:Statistical methodologies for human abuse potential studies are rarely evaluated. Human abuse potential studies assess whether test drugs produce positive and negative subjective responses on abuse-related measures using volunteers with histories of recreational drug use. These studies typically have a randomized, dou...

journal_title：Journal of biopharmaceutical statistics

authors： Chen L,Bonson KR

更新日期：2013-03-11 00:00:00

abstract：:In various pharmaceutical applications, repeated measurements are taken from each subject, and model parameters are estimated from the collected data. Examples include dose response modeling and PK/PD studies with serial blood sampling, among others. The quality of the information in an experiment is reflected in the ...

journal_title：Journal of biopharmaceutical statistics

authors： Gagnon R,Leonov S

更新日期：2005-01-01 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