A likelihood and resampling based approach to dichotomizing a continuous biomarker in medical research.

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 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：:The purpose of the research is to develop a statistical decision support algorithm for patients who may benefit from Adjuvant Cisplatin/Vinorelbine (ACT) and improve their survival rates. Genome-wide microarray data are used to identify feasible sets of genes and probe sets that constitute the gene signature. The data...

journal_title：Journal of biopharmaceutical statistics

authors： Moon H,Chao T,Ahn H

更新日期：2020-05-03 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 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：: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：: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：: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：: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：: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：:Multiple comparisons are commonly seen in clinical trials and many other fields. An example, which is the focus of this paper, is the comparison of several test treatments (possibly different doses of a compound) with placebo (control). It is well known that steps must be taken to control the type I error rate when mu...

journal_title：Journal of biopharmaceutical statistics

authors： Chen M,Kianifard F

更新日期：1997-07-01 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：:There are minimal standards for the processing of whole blood components, and to apply those standards requires a system of quality assurances. Excessive indications of failures in compliance trigger inspections and other remedial actions, but the demarcation of what is excessive is a critical issue. Issues of low vol...

journal_title：Journal of biopharmaceutical statistics

authors： Lachenbruch PA,Foulkes MA,Williams AE,Epstein JS

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：: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：: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：:The concept of quality by design (QbD) as published in ICH-Q8 is currently one of the most recurrent topics in the pharmaceutical literature. This guideline recommends the use of information and prior knowledge gathered during pharmaceutical development studies to provide a scientific rationale for the manufacturing p...

journal_title：Journal of biopharmaceutical statistics

authors： Lebrun P,Giacoletti K,Scherder T,Rozet E,Boulanger B

更新日期：2015-01-01 00:00:00

abstract：:Dunnett's many-to-one test is used frequently today, especially in dose-finding studies. Using Dunnett's test, the Type I error level for the comparison between the raw mean of the control and the raw means of the study drug groups can be exactly calculated for the normal data. However, this computability depends on t...

journal_title：Journal of biopharmaceutical statistics

authors： Shun Z,Silverberg A,Chang CK,Ouyang P

更新日期：2003-02-01 00:00:00

abstract：:To confirm results obtained from local evaluation at investigational centers, many oncology studies utilize blinded independent central review (BICR) to make assessments of the primary endpoint, progression-free survival (PFS). The comparison of data often leads to large discordances between these observations, castin...

journal_title：Journal of biopharmaceutical statistics

authors： Mannino FV,Amit O,Lahiri S

更新日期：2013-01-01 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：: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：:A model-based approach is developed to estimate the distribution of time from seroconversion to diagnosis with acquired immunodeficiency syndrome (AIDS) as a function of selected time-dependent covariates. The approach is applied to longitudinal data collected over 4 years of follow-up from 450 men seropositive for th...

journal_title：Journal of biopharmaceutical statistics

authors： Dunlop DD,Tamhane AC,Chmiel JS,Phair JP

更新日期：1994-07-01 00:00:00

abstract：:Bayesian statistical methodology has been used for more than 10 years in medical device premarket submissions to the U.S. Food and Drug Administration (FDA). A complete list of the publicly available information associated with these FDA applications is presented. In addition to the increasing number of Bayesian metho...

journal_title：Journal of biopharmaceutical statistics

authors： Campbell G

更新日期：2011-09-01 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：: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：: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：:An attractive application of expression technologies is to predict drug efficacy or safety using expression data of biomarkers. To evaluate the performance of various classification methods for building predictive models, we applied these methods on six expression datasets. These datasets were from studies using micro...

journal_title：Journal of biopharmaceutical statistics

authors： Man MZ,Dyson G,Johnson K,Liao B

更新日期：2004-11-01 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