New nonparametric confidence intervals for the Youden index.

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：:Hypoglycemia is a major safety concern for diabetic patients. Hypoglycemic events can be modeled based on time to recurrent events or count data. In this article, we evaluated a gamma frailty model with variance estimated by the inverse of observed Fisher information matrix, a gamma frailty model with the sandwich var...

journal_title：Journal of biopharmaceutical statistics

authors： Ma C,Qu Y,Fu H

更新日期：2020-05-18 00:00:00

abstract：:Sample size calculation based on normal approximations is often associated with the loss of statistical power for a single-arm trial with a time-to-event endpoint. Recently, Wu (2015) derived the exact variance for the one-sample log-rank test under the alternative and showed that a single-arm one-stage study based on...

journal_title：Journal of biopharmaceutical statistics

authors： Shan G

更新日期：2020-09-02 00:00:00

abstract：:Nonparametric versions of normal theory step-down multiple-test procedures for inferring minimum effective dose (see Tamhane et al. (1)) were developed and studied by Monte Carlo simulation. Two types of step-down testing procedures were examined. For both procedures, pairwise, linear, or Helmert contrasts of mean ran...

journal_title：Journal of biopharmaceutical statistics

authors： Sidik K,Morris RW

更新日期：1999-05-01 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：: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：: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：:We introduce the idea of a design to detect signals of efficacy in early phase clinical trials. Such a design features three possible decisions: to kill the compound; to continue with staged development; or to continue with accelerated development of the compound. We describe how such studies improve the trade-off bet...

journal_title：Journal of biopharmaceutical statistics

authors： Brown MJ,Chuang-Stein C,Kirby S

更新日期：2012-01-01 00:00:00

abstract：:In clinical trials of drug development, patients are often followed for a certain period of time, and the outcome variables are measured at scheduled time intervals. The main interest of the trial is the treatment efficacy at a prespecified time point, which is often the last visit. In such trials, patient dropout is ...

journal_title：Journal of biopharmaceutical statistics

authors： Kong F,Chen YF,Jin K

更新日期：2009-11-01 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：:Large sample size imbalance is not uncommon in the biosimilar development. At the beginning of a product development, sample sizes of a biosimilar and a reference product may be limited. Thus, a sample size calculation may not be feasible. During the development stage, more batches of reference products may be added a...

journal_title：Journal of biopharmaceutical statistics

authors： Dong XC,Weng YT,Tsong Y

更新日期：2017-01-01 00:00:00

abstract：:This article deals with seven special issues related to the assumptions, applicability, and practical use of formulas for calculating power or sample size, respectively, for comparative clinical trials with time-to-event endpoints, with particular focus on the well-known Freedman and Schoenfeld methods. All problems a...

journal_title：Journal of biopharmaceutical statistics

authors： Abel UR,Jensen K,Karapanagiotou-Schenkel I,Kieser M

更新日期：2015-01-01 00:00:00

abstract：:An important application of confirmatory adaptive designs is the data-driven selection of treatment arms in multi-armed trials. A general methodology for adaptive designs is based on the combination testing principle. Using this principle, selection of treatment arms in multi-armed designs, recalculation of sample siz...

journal_title：Journal of biopharmaceutical statistics

authors： Wassmer G

更新日期：2011-07-01 00:00:00

abstract：:The small n, Sequential, Multiple Assignment, Randomized Trial (snSMART) is a two-stage clinical trial design for rare diseases motivated by the comparison of three active treatments for isolated skin vasculitis in the ongoing clinical trial ARAMIS (a randomized multicenter study for isolated skin vasculitis, NCT09239...

journal_title：Journal of biopharmaceutical statistics

authors： Wei B,Braun TM,Tamura RN,Kidwell K

更新日期：2020-09-06 00:00:00

abstract：:The study of drug combinations has become important in drug development due to its potential for efficacy at lower, less toxic doses and the need to move new therapies rapidly into clinical trials. The goal is to identify which combinations are additive, synergistic, or antagonistic. Although there exists statistical ...

journal_title：Journal of biopharmaceutical statistics

authors： Fang HB,Tian GL,Li W,Tan M

更新日期：2009-07-01 00:00:00

abstract：:It has been widely recognized that interim analyses of accumulating data in a clinical trial can inflate type I error. Different methods, from group sequential boundaries to flexible alpha spending functions, have been developed to control the overall type I error at prespecified level. These methods mainly apply to t...

journal_title：Journal of biopharmaceutical statistics

authors： Chen LM,Ibrahim JG,Chu H

更新日期：2014-01-01 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：:To ensure that a drug product will meet standards for identity, strength and stability as specified in the United States Pharmacopedia and National Formulary (USP/NF), it needs to pass a number of tests such as the content uniformity test and dissolution test at various stages of the manufacturing process. The sponsor...

journal_title：Journal of biopharmaceutical statistics

authors： Wang H

更新日期：2007-01-01 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：: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：: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：:The Food and Drug Administration of the United States issued a draft guidance on adaptive design clinical trials in February 2010. This draft guidance has attracted a lot of attention because of the increasing interest in adaptive trials by the pharmaceutical industry in recent years. In this paper, we report on highl...

journal_title：Journal of biopharmaceutical statistics

authors： Chuang-Stein C,Beltangady M

更新日期：2010-11-01 00:00:00

abstract：:Multipopulation tailoring trials provide a trial design option that supports the realization of tailored therapeutics or personalized medicine. Several recent publications have focused on statistical and clinical considerations that arise in these trials that are designed to study the overall treatment effect in a pop...

journal_title：Journal of biopharmaceutical statistics

authors： Millen BA,Dmitrienko A,Song G

更新日期：2014-01-01 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：:The issue of consistency and reliability arises frequently in applied clinical trials, and there is a considerable amount of literature on this topic. For a continuous random variable, we describe a process to assess whether the mean and variance are the same from one evaluation to the other and we derive the intracla...

journal_title：Journal of biopharmaceutical statistics

authors： Kao TC,Sparling Y,Rochon J

更新日期：2003-08-01 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：: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：: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：: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：: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