Power and sample size for the S:T repeated measures design combined with a linear mixed-effects model allowing for missing data.

abstract：:Sample size adjustment at an interim analysis can mitigate the risk of failing to meet the study objective due to lower-than-expected treatment effect. Without modification to the conventional statistical methods, the type I error rate will be inflated, primarily caused by increasing sample size when the interim obser...

journal_title：Journal of biopharmaceutical statistics

authors： Chen YHJ,Yuan SS,Li X

更新日期：2018-01-01 00:00:00

abstract：:In this study, a Bayesian approach was suggested to estimate a change-point according to a covariate threshold when some patients never experienced the event of interest. Gibbs sampler algorithm with latent binary cure indicators was used to simplify the implementation of Markov chain Monte Carlo method. Then, the acc...

journal_title：Journal of biopharmaceutical statistics

authors： Shamsi F,Baghestani AR,Binesh F

更新日期：2020-03-01 00:00:00

abstract：:For the assessment of biosimilarity of biosimilar products, the United States (US) Food and Drug Administration (FDA) proposed a stepwise approach for providing the totality-of-the-evidence of similarity between a proposed biosimilar product and a US-licensed (reference) product. The stepwise approach starts with the ...

journal_title：Journal of biopharmaceutical statistics

authors： Wang T,Chow SC

更新日期：2017-01-01 00:00:00

abstract：:Using multistage adaptive group sequential test designs, the investigator may perform data-driven changes in the design during the course of the trial without inflation of the Type I error rate. This is possible, for example, through the use of the inverse normal method of combining the p-values from the separate stag...

journal_title：Journal of biopharmaceutical statistics

authors： Wassmer G

更新日期：2003-11-01 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：: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：: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：: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 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：: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：:Analyses of multicenter trials consider the estimated treatment effect differences of the individual centers and combine them into an estimate of the overall treatment effect. There has been much debate in the literature concerning the best way to combine these treatment effect differences. We emphasize that first of ...

journal_title：Journal of biopharmaceutical statistics

authors： Dragalin V,Fedorov V,Jones B,Rockhold F

更新日期：2001-11-01 00:00:00

abstract：:The problem of testing treatment difference in the occurrence of a study endpoint in a randomized parallel-group comparative clinical trial with repeated responses under the assumption that the responses follow a bivariate zero-inflated Poisson (ZIP) distribution is considered. Likelihood ratio test for homogeneity of...

journal_title：Journal of biopharmaceutical statistics

authors： Yuen HK,Chow SC,Tse SK

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 biologics products has received much attention from both biotechnology industry and the regulatory agencies. Unlike small-molecule drug products, the development of biologic products is very different and variable via the manufactu...

journal_title：Journal of biopharmaceutical statistics

authors： Hsieh TC,Chow SC,Liu JP,Hsiao CF,Chi E

更新日期：2010-01-01 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：:In 1968 the Food and Drug Administration (FDA) established the Adverse Event Reporting System (AERS) database containing data on adverse events (AEs) reported by patients, health care providers, and other sources through a spontaneous reporting system. FDA uses AERS for monitoring the safety of the drugs on the market...

journal_title：Journal of biopharmaceutical statistics

authors： Huang L,Zalkikar J,Tiwari RC

更新日期：2013-01-01 00:00:00

abstract：:We consider the problem of estimating a biomarker-based subgroup and testing for treatment effect in the overall population and in the subgroup after the trial. We define the best subgroup as the subgroup that maximizes the power for comparing the experimental treatment with the control. In the case of continuous outc...

journal_title：Journal of biopharmaceutical statistics

authors： Joshi N,Fine J,Chu R,Ivanova A

更新日期：2019-01-01 00:00:00

abstract：:Although asymptotically, the empirical covariance estimator is consistent and robust with respect to the selection of the working correlation matrix, when the sample size is small, its bias may not be negligible. This article proposes a small sample correction for the empirical covariance estimator in general Gaussian...

journal_title：Journal of biopharmaceutical statistics

authors： Fan C,Zhang D,Zhang CH

更新日期：2012-01-01 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：:Exact overall significance levels for selected sample sizes and response probabilities are graphically displayed when a dichotomous variable is compared between a placebo and two or more active treatments. A Z-statistic with a pooled variance estimator is used as the test statistic and critical values are based on the...

journal_title：Journal of biopharmaceutical statistics

authors： Whaley FS

更新日期：2003-11-01 00:00:00

abstract：:We present a new computational method for identifying regulated pathway components in transcript profiling (TP) experiments by evaluating transcriptional activity in the context of known biological pathways. We construct a graph representing thousands of protein functional relationships by integrating knowledge from p...

journal_title：Journal of biopharmaceutical statistics

authors： Pradines J,Rudolph-Owen L,Hunter J,Leroy P,Cary M,Coopersmith R,Dancik V,Eltsefon Y,Farutin V,Leroy C,Rees J,Rose D,Rowley S,Ruttenberg A,Wieghardt P,Sander C,Reich C

更新日期：2004-08-01 00:00:00

abstract：:Randomized controlled clinical trials often use a composite endpoint as a primary endpoint especially when treatment effects or frequency of individual components of the composite are likely to be small and combining them makes clinical sense for the disease under study. An advantage of the composite endpoint is that,...

journal_title：Journal of biopharmaceutical statistics

authors： Huque MF,Alosh M,Bhore R

更新日期：2011-07-01 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：: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：: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：: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：: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：: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：:A new two-stage design is proposed that is suitable for early detection of the anticancer activity of experimental therapies in Phase II oncology trials. The endpoints of interest are response rate and early progression rate. The anticancer activity is defined by a positive signal in one endpoint and a non-negative si...

journal_title：Journal of biopharmaceutical statistics

authors： Sun LZ,Chen C,Patel K

更新日期：2009-01-01 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：: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