scholarly journals A Test for Multiple Binary Endpoints with Continuous Latent Distribution in Clinical Trials

2021 ◽  
Vol 20 (4) ◽  
pp. 463-480
Author(s):  
Takuma Ishihara ◽  
Kouji Yamamoto
Keyword(s):  
Clinical Trials ◽  
Latent Variables ◽  
Testing Procedure ◽  
Association Measure ◽  
Binary Responses ◽  
Testing Procedures ◽  
Primary Endpoints ◽  
Latent Distribution ◽  
Multiple Primary ◽  
Continuous Responses

AbstractIn clinical trials, two or more binary responses obtained by dichotomizing continuous responses are often employed as multiple primary endpoints. Testing procedures for multiple binary variables with latent distribution have not yet been adequately discussed. Based on the association measure among latent variables, we provide a statistic for testing the superiority of at least one binary endpoint. In addition, we propose a testing procedure with a framework in which the trial efficacy is confirmed only when there is superiority of at least one endpoint and non-inferiority of the remaining endpoints. The performance of the proposed procedure is evaluated through simulations.

scholarly journals Statistical Issues in Clinical Trials with Multiple Primary Endpoints

2013 ◽  
Vol 34 (1) ◽  
pp. 35-52
Author(s):  
Takashi Sozu ◽  
Tomoyuki Sugimoto ◽  
Toshimitsu Hamasaki
Keyword(s):  
Clinical Trials ◽  
Primary Endpoints ◽  
Multiple Primary ◽  
Statistical Issues

Design and Analysis of Group Sequential Clinical Trials with Multiple Primary Endpoints

Biometrics ◽  
2004 ◽  
Vol 60 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Michael R. Kosorok ◽  
Shi Yuanjun ◽  
David L. DeMets
Keyword(s):  
Clinical Trials ◽  
Group Sequential ◽  
Primary Endpoints ◽  
Multiple Primary

Reference-based pattern-mixture models for analysis of longitudinal binary data

2020 ◽  
Vol 29 (12) ◽  
pp. 3770-3782
Author(s):  
Kaifeng Lu
Keyword(s):  
Latent Variables ◽  
Binary Data ◽  
Treatment Effectiveness ◽  
Probit Model ◽  
Primary Analysis ◽  
Binary Responses ◽  
Pattern Mixture Model ◽  
Longitudinal Binary Data ◽  
Continuous Responses ◽  
Using Data

Pattern-mixture model (PMM)-based controlled imputations have become a popular tool to assess the sensitivity of primary analysis inference to different post-dropout assumptions or to estimate treatment effectiveness. The methodology is well established for continuous responses but less well established for binary responses. In this study, we formulate the copy-reference and jump-to-reference PMMs for longitudinal binary data using a multivariate probit model with latent variables. We discuss the maximum likelihood, Bayesian, and multiple imputation methods for estimating the treatment effect under the specified PMM. Simulation studies are conducted to evaluate the performance of these methods. These methods are also illustrated using data from a bipolar mania study.

Reducing unnecessary measurements in clinical trials with multiple primary endpoints

2016 ◽  
Vol 26 (4) ◽  
pp. 631-643 ◽  
Author(s):  
Takashi Sozu ◽  
Tomoyuki Sugimoto ◽  
Toshimitsu Hamasaki
Keyword(s):  
Clinical Trials ◽  
Primary Endpoints ◽  
Multiple Primary

scholarly journals Clinical trial registries as Scientometric data: A novel solution for linking and deduplicating clinical trials from multiple registries

2021 ◽  
Author(s):  
Christian Thiele ◽  
Gerrit Hirschfeld ◽  
Ruth von Brachel
Keyword(s):  
Clinical Trials ◽  
Random Forest ◽  
Random Forest Model ◽  
Scientometric Analysis ◽  
Data Set ◽  
The Public ◽  
Forest Model ◽  
Clinical Trial Registries ◽  
Multiple Primary ◽  
Clinical Trials Registry

AbstractRegistries of clinical trials are a potential source for scientometric analysis of medical research and serve important functions for the research community and the public at large. Clinical trials that recruit patients in Germany are usually registered in the German Clinical Trials Register (DRKS) or in international registries such as ClinicalTrials.gov. Furthermore, the International Clinical Trials Registry Platform (ICTRP) aggregates trials from multiple primary registries. We queried the DRKS, ClinicalTrials.gov, and the ICTRP for trials with a recruiting location in Germany. Trials that were registered in multiple registries were linked using the primary and secondary identifiers and a Random Forest model based on various similarity metrics. We identified 35,912 trials that were conducted in Germany. The majority of the trials was registered in multiple databases. 32,106 trials were linked using primary IDs, 26 were linked using a Random Forest model, and 10,537 internal duplicates on ICTRP were identified using the Random Forest model after finding pairs with matching primary or secondary IDs. In cross-validation, the Random Forest increased the F1-score from 96.4% to 97.1% compared to a linkage based solely on secondary IDs on a manually labelled data set. 28% of all trials were registered in the German DRKS. 54% of the trials on ClinicalTrials.gov, 43% of the trials on the DRKS and 56% of the trials on the ICTRP were pre-registered. The ratio of pre-registered studies and the ratio of studies that are registered in the DRKS increased over time.

scholarly journals First-Line Maintenance Treatment in Metastatic Colorectal Cancer (mCRC): Quality and Clinical Benefit Overview

2021 ◽  
Vol 10 (3) ◽  
pp. 470
Author(s):  
Marta Martín-Richard ◽  
Maria Tobeña
Keyword(s):  
Colorectal Cancer ◽  
Clinical Trials ◽  
Clinical Benefit ◽  
Maintenance Treatment ◽  
Randomized Clinical Trials ◽  
Line Treatment ◽  
First Line ◽  
Design Quality ◽  
Primary Endpoints ◽  
First Line Treatment

Different strategies of maintenance therapy (sequential CT, intermittent CT, intermittent CT and MAbs, or de-escalation MAbs monotherapy) after first-line treatment are undertaken. Many randomized clinical trials (RCT), which evaluated these approaches, suffer from incorrect design, heterogenous primary endpoints, inadequate size, and other methodology flaws. Drawing any conclusions becomes challenging and recommendations are mainly vague. We evaluated those studies from another perspective, focusing on the design quality and the clinical benefit measure with a more objective and accurate methodology. These data allowed a clearer and more exact overview of the statement in maintenance treatment.

scholarly journals A Comparison of the Randomized Clinical Trial Efficacy and Real-World Effectiveness of Tofacitinib for the Treatment of Inflammatory Bowel Disease: A Cohort Study

2019 ◽  
Author(s):  
Vivek A. Rudrapatna ◽  
Benjamin S. Glicksberg ◽  
Atul J. Butte
Keyword(s):  
Ulcerative Colitis ◽  
Clinical Trials ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Real World ◽  
Controlled Trials ◽  
Real World Data ◽  
Eligibility Criteria ◽  
Primary Endpoints ◽  
Three Phase

AbstractBackgroundReal-world data are receiving attention from regulators, biopharmaceuticals and payors as a potential source of clinical evidence. However, the suitability of these data to produce evidence commensurate with randomized controlled trials (RCTs) and the best practices in their use remain unclear. We sought to compare the real-world effectiveness of Tofacitinib in the treatment of IBD against efficacy rates published by corresponding RCTs.MethodsElectronic health records at the University of California, San Francisco (UCSF) were queried and reviewed to identify 86 Tofacitinib-treated IBD patients through 4/2019. The primary endpoint was treatment effectiveness. This was measured by time-to-treatment-discontinuation and by the primary endpoints of RCTs in Ulcerative Colitis (UC) and Crohn’s Disease (CD). Endpoints were measured and analyzed following a previously published protocol and analysis plan.Findings86 patients (68 with UC, 18 with CD) initiated Tofacitinib for IBD treatment. Most of the data needed to calculate baseline and follow-up disease activity indices were documented within the EHR(77% for UC, 91% for CD). Baseline characteristics of the UCSF and RCT cohorts were similar, except for a longer disease duration and 100% treatment failure of Tumor Necrosis Factor inhibitors in the former. None of the UCSF cohort would have met the RCT eligibility criteria due to multiple reasons.The rate of achieving the RCT primary endpoints were highly similar to the published rates for both UC(16%, P=0·5) and CD (38%, P=0·8). However, treatment persistence was substantially higher: 69% for UC (week 52) and 75% for CD (week 26).InterpretationAn analysis of routinely collected clinical data can reproduce published Tofacitinib efficacy rates, but also indicates far greater treatment durability than suggested by RCTs including possible benefit in CD. These results underscore the value of real-world studies to complement RCTs.FundingThe National Institutes of Health and UCSF Bakar InstituteResearch in ContextEvidence before this studyTofacitinib is the most recently approved treatment for Ulcerative Colitis. Data related to treatment efficacy for either IBD subtype is generally limited, whether from controlled trials or real-world studies. A search of clinicaltrials.gov was performed in January 2019 for completed phase 2 or 3, interventional, placebo-controlled clinical trials matching the terms “Crohn’s Disease” OR “Ulcerative Colitis” in the conditions field, and matching “Placebo” AND “Tofacitinib” OR “CP-690,550”) in the Interventions field. We identified three Phase 3 trials for UC (OCTAVE trials, all initially reported in a single article in 2016) and three Phase 2 trials of CD (two published in the same article in 2017, one reported in 2014). The Phase 3 UC trials reported 57·6% pooled clinical response rate in the Tofacitinib-assigned groups after 8 weeks (induction), and a 37·5% pooled remission rate among eligible induction trial responders in the Tofacitinib-assigned groups at 52 weeks. The 2017 CD trial reported a 70·8% pooled rate of response or remission in the Tofacitinib-assigned groups after 8 weeks, and a 47·6% pooled rate of response or remission among enrolled induction-trial responders at 26 weeks. A bias assessment of both UC and CD trials indicated a high risk of attrition bias and unclear risk of bias related to conflicts of interest. We also performed a search of pubmed.gov in January 2019 using search terms (“Colitis” OR “Crohn’s”) AND (“Tofacitinib” OR “CP-690,550”) OR “real-world” to identify cohort studies of Tofacitinib efficacy in routine clinical practice. No studies meeting these criteria were identified.Added value of this studyThis is one of the early studies to closely compare the results of clinical trials with the continuously-updated data captured in the electronic health records, and the very the first to assess the efficacy-effectiveness gap for Tofacitinib. We found that none of the patients treated at our center thus far would have qualified for the clinical trial based on published eligibility criteria. We found that the drug appeared to perform similarly to its efficacy when using the endpoints reported in clinical trials, but treatment persistence was significantly greater than would have been expected from the reported trial outcomes: 69% for UC at week 52 and 75% for CD at week 26.Implications of all the available evidenceTofacitinib is an effective treatment for the Ulcerative colitis and may be efficacious for Crohn’s disease. Controlled trials may not be representative of real-world cohorts, may not be optimally designed to identify efficacious drugs, and may not accurately predict patterns of use in clinical practice. Further studies using real-world data as well as methods to enable their proper use are needed to confirm and continuously monitor the efficacy and safety of drugs, both for on- and off-label use.

Usefulness of Cation Exchange High Performance Liquid Chromatography as a Testing Procedure

PEDIATRICS ◽  
1989 ◽  
Vol 83 (5) ◽  
pp. 849-851
Author(s):  
Titus H. J. Huisman
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cation Exchange ◽  
Cellulose Acetate ◽  
Isoelectric Focusing ◽  
High Performance ◽  
Testing Procedure ◽  
Cellulose Acetate Electrophoresis ◽  
Blood Samples ◽  
Testing Procedures

Testing of cord blood or newborn blood samples for hemoglobin abnormalities should include clinically important hemoglobinopathies other than sickle cell anemia (SS), such as SC, SD, SO, S-β- thalassemia (thal), EE, SE, and α-thal, and should place the quality of the testing procedures (ie, accuracy of diagnosis) above quantity (ie, number of samples tested over a given period). There is no single method available that is suitable for the identification of each of the numerous abnormalities; thus, at least two, and often more than two, procedures must be used to reach a definitive diagnosis. For this reason, blood samples collected in vacutainers with ethylenediaminetetraacetic acid as anticoagulant are preferred to those collected on filter papers. The latter approach also has the disadvantage that, under a less than optimal transport system, hemoglobin is readily modified (oxidation, glycosylation, protein-protein interaction), producting extra bands or peaks in electrophoretic or chromatographic separations that interfere with an appropriate identification of various genetically determined hemoglobin variants. In our laboratories, in which hemoglobin identification has been routine for more than 25 years, we consider the following procedures acceptable primary testing methods: starch gel electrophoresis at pH 8.9, cellulose acetate electrophoresis at pH 8.5 to 8.9, isoelectric focusing, and fast cation exchange high performance liquid chromatography (HPLC). The following five methods are excellent confirmatory testing procedures: citrate agar electrophoresis at pH 6.1, cation or anion exchange macrochromatography, isoelectric focusing, cation exchange HPLC, and immunologic procedures. Combinations of these techniques will often lead to acceptable data, and the general approach followed in our institute is given in Fig 1. Cellulose acetate electrophoresis at alkaline pH is still the primary testing procedure, and citrate agar electrophoresis at pH 6.1 and micro-HPLC procedures are the main confirmatory methods.

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