Intent-to-randomize corrections for missing data resulting from run-in selection bias in clinical trials for chronic conditions.

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：: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：: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：: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：: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：: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：: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：: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：: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：:Assessment of quality of life (QOL) in clinical trials becomes a challenging task from the viewpoint of clinical biostatistics. The responses of the items for measuring QOL indices usually vary widely from patient to patient and from time to time. Measurement errors might be present in the responses of the items, and ...

journal_title：Journal of biopharmaceutical statistics

authors： Siddiqui O,Ali MW

更新日期：1999-11-01 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：: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：:A test and a reference analytical method are usually compared for agreement based on paired data obtained from several independent subjects. Bias between two methods can be classified as constant and proportional. In this article, we provide an approach for maximum likelihood estimation of total bias between two metho...

journal_title：Journal of biopharmaceutical statistics

authors： Magari RT

更新日期：2004-11-01 00:00:00

abstract：:Pharmacokinetic studies of drug and metabolite concentrations in the blood are usually conducted as crossover trials, especially in phases I and II. A longitudinal series of measurements is collected on each subject within each period. However, much of the dependence among such observations, within and between periods...

journal_title：Journal of biopharmaceutical statistics

authors： Lindsey JK,Wang J,Byrom WD,Jones B

更新日期：1999-08-01 00:00:00

abstract：:Classification measures play essential roles in the assessment and construction of classifiers. Hence, determining how to prevent these measures from being affected by individual observations has become an important problem. In this paper, we propose several indexes based on the influence function and the concept of l...

journal_title：Journal of biopharmaceutical statistics

authors： Ke BS,Chiang AJ,Chang YI

更新日期：2018-01-01 00:00:00

abstract：:An integral part of routine health checkups involves laboratory measurements on various analytes in the blood. It is then common to compare the value of two consecutive measurements sampled at different times from the same patient. A "significant" change requires an action (additional sample and/or clinical action). T...

journal_title：Journal of biopharmaceutical statistics

authors： Cohen A,Doveh E,Umansky T

更新日期：2001-01-01 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：:We would like to estimate the parameters of a dose-response function with the greatest precision as possible. For a two-parameter model, this is equivalent to minimizing the area of the confidence ellipsoid, i.e., a D-optimal design. Previous work on this particular model has included minimal designs. These designs ar...

journal_title：Journal of biopharmaceutical statistics

authors： Lupinacci PJ,Raghavarao D

更新日期：2000-02-01 00:00:00

abstract：:There is often a need to determine parallelism or linearity between pairs of dose-response data sets for various biological applications. This article describes a technique based on a modification of the well-known extra-sum-of-squares principle of statistical regression. The standard extra-sum-of-squares method uses ...

journal_title：Journal of biopharmaceutical statistics

authors： Gottschalk PG,Dunn JR

更新日期：2005-01-01 00:00:00

abstract：:In recent years, multi-regional clinical trials (MRCT) that conduct clinical trials simultaneously in Asian Pacific region, Europe, and the United States have become very popular for global pharmaceutical development. The main purpose of multi-regional clinical trials is to shorten the time for pharmaceutical developm...

journal_title：Journal of biopharmaceutical statistics

authors： Ying L,Song F,Chow SC,Zeng N,Zheng J,Li X,Henry D,Sethuraman V

更新日期：2018-01-01 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：: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：:Clinical trials often use a binary "fold increase" endpoint defined according to the ratio of interval-censored measurement at end-of-study to that at baseline. We propose a simple yet principled analytic approach based on the linear mixed-effects model for interval-censored data for the analysis of such paired measur...

journal_title：Journal of biopharmaceutical statistics

authors： Xu Y,Lam KF,Ooi EE,Wilder-Smith A,Paton NI,Lee LS,Cheung YB

更新日期：2015-01-01 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：: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：: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：:In this article, a parametric sequential test is proposed under the Weibull model. The proposed test is asymptotically normal with an independent increment structure. The sample size for a fixed sample test is derived for the purpose of group sequential trial design. In addition, a multi-stage group sequential procedu...

journal_title：Journal of biopharmaceutical statistics

authors： Wu J,Xiong X

更新日期：2015-01-01 00:00:00

abstract：:ETRANK is a statistical software which uses nonparametric (randomization) technique to analyze incomplete repeated measures data, where the pattern of withdrawal is treatment related. This stand alone program is written in C, presently runs in MS-DOS, and a Windows version is in development. The program has been devel...

journal_title：Journal of biopharmaceutical statistics

authors： Entsuah R

更新日期：1996-11-01 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：: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