Data-driven analysis strategies for proportion studies in adaptive group sequential test designs.

abstract：:In the early stages of traditional drug development, the frequency of dosing (e.g., QD, BID, etc.) is typically determined by the pharmacokinetic properties of a compound. After an appropriate dose frequency is chosen, the magnitude of dose is then evaluated via parallel-group dose-response trials. For some drugs, how...

journal_title：Journal of biopharmaceutical statistics

authors： Hafner KB,Ruberg SJ

更新日期：1996-07-01 00:00:00

abstract：:The world of medical devices while highly diverse is extremely innovative, and this facilitates the adoption of innovative statistical techniques. Statisticians in the Center for Devices and Radiological Health (CDRH) at the Food and Drug Administration (FDA) have provided leadership in implementing statistical innova...

journal_title：Journal of biopharmaceutical statistics

authors： Campbell G,Yue LQ

更新日期：2016-01-01 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：:Failure to recognize the serious implications of heterogeneous correlations and disregard of the multiple test problem in interpreting the results from repeated measurements ANOVA of any single primary outcome measure can produce false-positive error rates that are more than five times the alpha level that is reported...

journal_title：Journal of biopharmaceutical statistics

authors： Overall JE,Doyle SR

更新日期：1996-03-01 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 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：:The design of a three-arm trial including the experimental treatment, an active reference treatment, and a placebo is recommended as a useful approach to the assessment of noninferiority of the experimental treatment. The inclusion of the placebo arm enables the assessment of assay sensitivity and internal validation,...

journal_title：Journal of biopharmaceutical statistics

authors： Hida E,Tango T

更新日期：2013-01-01 00:00:00

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：:Pharmaceutical product development culminates in confirmatory trials whose evidence for the product's efficacy and safety supports regulatory approval for marketing. Regulatory agencies in countries whose patients were not included in the confirmatory trials often require confirmation of efficacy and safety in their p...

journal_title：Journal of biopharmaceutical statistics

authors： Gould AL,Jin T,Zhang LX,Wang WW

更新日期：2012-09-01 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：: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：: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：:We propose an adaptive two-stage dose-response design where a prespecified adaptation rule is used to add and/or drop treatment arms between the stages. We extend the multiple comparison procedures-modeling (MCP-Mod) approach into a two-stage design. In each stage, we use the same set of candidate dose-response models...

journal_title：Journal of biopharmaceutical statistics

authors： Franchetti Y,Anderson SJ,Sampson AR

更新日期：2013-01-01 00:00:00

abstract：:Predictive probability is particularly useful in aiding a decision-making process related to drug development. This is especially true for decisions occurring as the result of interim analyses of clinical trials. Examples of clinical trial applications of Bayesian predictive probability and the use of the beta-binomia...

journal_title：Journal of biopharmaceutical statistics

authors： Johns D,Andersen JS

更新日期：1999-03-01 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：:The purpose of this paper is to describe, illustrate, and compare a number of different approaches to the analysis of repeated binary and categorical data. These approaches include empirical generalized least squares and generalized estimating equations, as well as traditional log-linear modeling methods. It is shown ...

journal_title：Journal of biopharmaceutical statistics

authors： Kenward MG,Jones B

更新日期：1992-01-01 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：: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：: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：: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：: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：: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：: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：: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：:A common question in clinical studies is how to use historical data from earlier studies, leveraging relevant information into the design and analysis of a new study. Bayesian approaches are particularly well-suited to this task, with their natural ability to borrow strength across data sources. In this paper, we prop...

journal_title：Journal of biopharmaceutical statistics

authors： Li JX,Chen WC,Scott JA

更新日期：2016-01-01 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

abstract：:Some statistical methods applied to in vitro diagnostic tests for the three primary indications (screening, diagnosis, and monitoring) are discussed. Various examples with practical statistical applications are presented, including test for k by k ordered categorical matched-pair data for screening of cervical cancer,...

journal_title：Journal of biopharmaceutical statistics

authors： Lao CS

更新日期：1997-11-01 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 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：:When marketed lots of pharmaceutical products produce a number of out-of-specification (OOS) samples, it can be very disruptive. In some cases such lots must be recalled, at substantial expense. We present a model of the probability of OOS samples and show quantitatively how this probability depends on the underlying ...

journal_title：Journal of biopharmaceutical statistics

authors： Fairweather WR

更新日期：2003-08-01 00:00:00