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 trajectories of viral loads tend to show a gradual change from a declining trend after initiation of treatment to an increasing trend without an abrupt change. Such characteristics of trajectories are also associated with a time-to-event process. To assess these clinically important features, we develop a joint bent-cable Tobit model for the time-to-event and left-censored response variable with skewness and phasic developments. Random effects are used to determine the stochastic dependence between the time-to-event process and response process. The proposed method is illustrated using real data from an AIDS clinical study.
journal_name
J Biopharm Statjournal_title
Journal of biopharmaceutical statisticsauthors
Dagne GAdoi
10.1080/10543406.2017.1321006subject
Has Abstractpub_date
2018-01-01 00:00:00pages
385-401issue
3eissn
1054-3406issn
1520-5711journal_volume
28pub_type
杂志文章abstract::The dose-response models for full agonists and for a particular type of partial agonist can be described by sigmoidal curves and bell-shaped curves, respectively. The methods currently used to evaluate the interaction of a full agonist and a partial agonist require a large number of experimental units and base their a...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543409808835266
更新日期:1998-11-01 00:00:00
abstract::The potency of a batch of drug product needs to meet a release limits at the time of release so that the potency at the end of shelf life remains above the lower registration limit (LRL). This article discusses two methods which determine the release limits such that the chance to fail LRL at the end of shelf life of ...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543409808835225
更新日期:1998-03-01 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
pub_type: 杂志文章
doi:10.1081/BIP-200025678
更新日期:2004-08-01 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
pub_type: 杂志文章
doi:10.1080/10543409608835141
更新日期:1996-07-01 00:00:00
abstract::In various pharmaceutical applications, repeated measurements are taken from each subject, and model parameters are estimated from the collected data. Examples include dose response modeling and PK/PD studies with serial blood sampling, among others. The quality of the information in an experiment is reflected in the ...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1081/bip-200040853
更新日期:2005-01-01 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
pub_type: 杂志文章
doi:10.1080/10543400601001527
更新日期:2007-01-01 00:00:00
abstract::The ICH E14 guidance (ICH, 2005) recommend that a concurrent positive control should be included in a thorough QTc clinical trial to validate the study. The ICH E14 guidance (ICH, 2005) state that "The positive control should have an effect on the mean QTc interval of about 5 ms (i.e., an effect that is close to the Q...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543400801995478
更新日期:2008-01-01 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
pub_type: 杂志文章
doi:10.1081/BIP-120017723
更新日期:2003-02-01 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
pub_type: 杂志文章
doi:10.1080/10543400500406595
更新日期:2006-01-01 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
pub_type: 杂志文章
doi:10.1081/BIP-100101000
更新日期:1999-03-01 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
pub_type: 杂志文章
doi:10.1081/BIP-100101173
更新日期:1999-05-01 00:00:00
abstract::In analytical similarity assessment of a biosimilar product, key quality attributes of the test and reference products need to be shown statistically similar. When there were multiple references, similarity among the reference products is also required. We proposed a simultaneous confidence approach based on the fiduc...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543406.2019.1657142
更新日期:2019-01-01 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
pub_type: 杂志文章
doi:10.1080/10543406.2020.1730877
更新日期:2020-05-03 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
pub_type: 杂志文章
doi:10.1080/10543400701697158
更新日期:2008-01-01 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
pub_type: 杂志文章
doi:10.1080/10543406.2020.1765370
更新日期:2020-05-18 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
pub_type: 杂志文章
doi:10.1080/10543406.2014.941983
更新日期:2014-01-01 00:00:00
abstract::The proportion ratio (PR) of a positive response between an experimental treatment and a standard treatment (or placebo) is often used to measure the relative treatment efficacy in a randomized clinical trial (RCT). For ethical reasons, it is almost inevitable to encounter some patients not complying with their assign...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543406.2010.508139
更新日期:2012-01-01 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
pub_type: 杂志文章
doi:10.1080/10543406.2013.792827
更新日期:2013-01-01 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
pub_type: 杂志文章
doi:10.1080/10543400903315757
更新日期:2010-09-01 00:00:00
abstract::Tango (Biostatistics 2016) proposed a new repeated measures design called the S:T repeated measures design, combined with generalized linear mixed-effects models and sample size calculations for a test of the average treatment effect that depend not only on the number of subjects but on the number of repeated measures...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543406.2017.1293083
更新日期:2017-01-01 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
pub_type: 杂志文章
doi:10.1080/10543400701329497
更新日期:2007-01-01 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
pub_type: 杂志文章
doi:10.1081/BIP-100101186
更新日期:1999-08-01 00:00:00
abstract::We address the issue of analysis of clinical data generated by the bridging study conducted in the new region to evaluate the similarity for extrapolation of the foreign clinical data. A bridging study is usually conducted in the new region only after the test product is approved for commercial marketing in the origin...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1081/bip-120014568
更新日期:2002-08-01 00:00:00
abstract::This paper introduces exact permutation methods for use when there are independent clusters of data with arbitrary within-cluster correlation. To eliminate the problem of clustering, we randomly select a data point from each cluster and for this now independent data, and calculate our test statistic and the associated...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543401003618884
更新日期:2010-07-01 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
pub_type: 杂志文章,评审
doi:10.1080/10543409208835036
更新日期:1992-01-01 00:00:00
abstract::Gene expression profiling has played an important role in cancer risk classification and has shown promising results. Since gene expression profiling often involves determination of a set of top rank genes for analysis, it is important to evaluate how modeling performance varies with the number of selected top ranked ...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543400802277967
更新日期:2008-01-01 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
pub_type: 杂志文章
doi:10.1081/BIP-200035450
更新日期:2004-11-01 00:00:00
abstract::Administration of biological therapeutics can generate undesirable immune responses that may induce anti-drug antibodies (ADAs). Immunogenicity can negatively affect patients, ranging from mild reactive effect to hypersensitivity reactions or even serious autoimmune diseases. Assessment of immunogenicity is critical a...
journal_title:Journal of biopharmaceutical statistics
pub_type: 杂志文章
doi:10.1080/10543406.2014.972515
更新日期:2015-01-01 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
pub_type: 杂志文章
doi:10.1081/BIP-120022773
更新日期:2003-08-01 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
pub_type: 临床试验,杂志文章
doi:10.1080/10543409408835078
更新日期:1994-07-01 00:00:00