Design effects for highly clustered count data with varying length of follow-up--applying to the analysis of ICD shocks.

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：:When performing a pivotal clinical trial, it may be of interest to assess the probability of success (PoS) of that trial. Initially evaluated when the trial is designed, PoS can be updated as the trial progresses and new information about the drug effect becomes available. Such information can be external to the trial...

journal_title：Journal of biopharmaceutical statistics

authors： Rufibach K,Jordan P,Abt M

更新日期：2016-01-01 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：: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：: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：: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：: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 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：:In this paper, a propensity score-integrated composite likelihood (PSCL) approach is developed for cases in which the control arm of a two-arm randomized controlled trial (RCT) (treated vs control) is augmented with patients from real-world data (RWD) containing both clinical outcomes and covariates at the patient-lev...

journal_title：Journal of biopharmaceutical statistics

authors： Chen WC,Wang C,Li H,Lu N,Tiwari R,Xu Y,Yue LQ

更新日期：2020-05-03 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：:We propose a new adaptive threshold detection and enrichment design in which the biomarker threshold is adaptively estimated and updated by optimizing a trade-off between the size of the biomarker positive population and the magnitude of the treatment effect in that population. Enrichment is based on an enrollment cri...

journal_title：Journal of biopharmaceutical statistics

authors： Wang T,Wang X,George SL,Zhou H

更新日期：2020-11-11 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：: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：: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：:Drug-related side effects are one of the leading causes of death and illness in the developed world. Finding genes that modify drug response has the potential to significantly improve drug delivery, by identifying both individuals that can benefit from therapy and those at increased risk of harm. We present a simple a...

journal_title：Journal of biopharmaceutical statistics

authors： He M,Allen A

更新日期：2010-03-01 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：:During preclinical drug development, the immune system is specifically evaluated after prolonged treatment with drug candidates, because the immune system may be an important target system. The response of antibodies against a T-cell-dependent antigen is recommenced by the FDA and EMEA for the evaluation of immunosupp...

journal_title：Journal of biopharmaceutical statistics

authors： Shkedy Z,Straetemans R,Molenberghs G,Desmidt M,Vinken P,Goeminne N,Coussement W,Van Den Poel B,Bijnens L

更新日期：2005-01-01 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：: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, 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：: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 new three-arm parallel design was recently proposed to investigate the biosimilarity between a biological product and a reference product by using the relative distance. The purpose of this article is to extend their results to binary endpoints for three popular metrics: the risk difference, the log relative risk, a...

journal_title：Journal of biopharmaceutical statistics

authors： Shin W,Kang SH

更新日期：2016-01-01 00:00:00

abstract：:Some current approaches to modeling crossover trials in two treatments are critically reviewed from the perspective of the practical requirements of the drug developer. Particular attention is paid to the AB/BA design, and the inadequacies of the once popular two-stage procedure are discussed in detail. The use of bas...

journal_title：Journal of biopharmaceutical statistics

authors： Grieve A,Senn S

更新日期：1998-05-01 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：: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：:Sample size estimation (SSE) is an important issue in the planning of clinical studies. While larger studies are likely to have sufficient power, it may be unethical to expose more patients than necessary to answer a scientific question. Budget considerations may also cause one to limit the study to an adequate size t...

journal_title：Journal of biopharmaceutical statistics

authors： Wu PS,Lin M,Chow SC

更新日期：2016-01-01 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：: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：: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：: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