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Vester J, Bornstein N, Heiss WD, Vosko M, Moessler H, Jech M, Winter S, Brainin M. C-REGS 2 - Design and methodology of a high-quality comparative effectiveness observational trial. J Med Life 2022; 14:700-709. [PMID: 35027974 PMCID: PMC8742899 DOI: 10.25122/jml-2021-0362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/30/2021] [Indexed: 12/03/2022] Open
Abstract
The main aim of this study is to systematically record Cerebrolysin treatment modalities and concomitant medication, according to local standards, in patients with moderate to severe neurological deficits after acute ischemic stroke and to assess the impact of these parameters on therapy outcome during early rehabilitation (day 21) and on day 90. An open observational treatment design based on the principles of high-quality comparative effectiveness research (HQCER) has been chosen to capture the therapies as applied in real-world clinical practice. HQCER opens a new horizon for strengthening the validity of the results from observational trials, thereby enhancing the associated level of evidence. Rigorous pre-specification of analytical procedures and tight risk-based centralized monitoring were additional measures to improve the impact of the observational approach. The value for real-world studies has become obvious, and such studies based on comparative effectiveness designs supplement the classical study designs by enabling the inclusion of larger proband numbers and more statistical reliability for practical use.
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Affiliation(s)
- Johannes Vester
- Department of Biometry and Clinical Research, idv Data Analysis and Study Planning, Krailling, Germany
| | - Natan Bornstein
- Department of Neurology, Shaare Zedek Medical Center, Tel Aviv, Israel
| | - Wolf-Dieter Heiss
- Department of Neurology, Max Planck Institute for Metabolism Research, Koln, Germany
| | - Milan Vosko
- Department of Neurology, Kepler University Hospital, Linz, Austria
| | | | - Marion Jech
- Department of Research and Development, Ever Neuro Pharma, Unterach, Austria
| | - Stefan Winter
- Department of Research and Development, Ever Neuro Pharma, Unterach, Austria
| | - Michael Brainin
- Department of Clinical Neurosciences and Preventive Medicine, Danube University Krems, Krems, Austria
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Ding AA, Wu SS, Dean NE, Zahigian RS. Two-stage adaptive enrichment design for testing an active factor. J Biopharm Stat 2019; 30:18-30. [PMID: 31135263 DOI: 10.1080/10543406.2019.1609015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We propose an adaptive enrichment approach to test an active factor, which is a factor whose effect is non-zero in at least one subpopulation. We implement a two-stage play-the-winner design where all subjects in the second stage are enrolled from the subpopulation that has the highest observed effect in the first stage. We recommend a weighted Fisher's combination of the most powerful test for each stage, respectively: the first stage Hotelling's test and the second stage noncentral chi-square test. The test is further extended to cover binary outcomes and time-to-event outcomes.
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Affiliation(s)
- A Adam Ding
- Department of Mathematics, Northeastern University, Boston, Massachusetts, USA
| | - Samuel S Wu
- Department of Biostatistics, University of Florida, Gainesville, Florida, USA
| | - Natalie E Dean
- Department of Biostatistics, University of Florida, Gainesville, Florida, USA
| | - Rachel S Zahigian
- Department of Biostatistics, University of Florida, Gainesville, Florida, USA
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Goncalves TM, Southey BR, Rodriguez-Zas SL. Interplay Between Amphetamine and Activity Level in Gene Networks of the Mouse Striatum. Bioinform Biol Insights 2018; 12:1177932218815152. [PMID: 30559594 PMCID: PMC6291885 DOI: 10.1177/1177932218815152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 10/18/2018] [Indexed: 01/09/2023] Open
Abstract
The psychostimulant amphetamine can be prescribed to ameliorate the symptoms of narcolepsy, attention-deficit hyperactivity disorder and to facilitate weight loss. This stimulant can also have negative effects including toxicity and addiction risk. The impact of amphetamine on gene networks is partially understood and this study addresses this gap in consideration of the physical activity. The striata of mice exposed to either amphetamine or saline treatment were compared in a mouse line selected for home cage physical overactivity, a phenotype that can be mitigated with amphetamine, and in a contemporary control line using RNA-seq. Genes presenting opposite expression patterns between treatments across lines included a pseudogene of coiled-coil-helix-coiled-coil-helix domain containing 2 gene (Chchd2), ribonuclease P RNA component H1 (Rpph1), short stature homeobox 2 (Shox2), transient receptor potential melastatin 6 (Trpm6), and tumor necrosis factor receptor superfamily, member 9 (Tnfrsf9). Genes presenting consistent treatment patterns across lines, albeit at different levels of significance included cholecystokinin (Cck), vasoactive intestinal polypeptide (Vip), arginine vasopressin (Avp), oxytocin/neurophysin (Oxt), thyrotropin releasing hormone (Trh), neurotensin (Nts), angiotensinogen (Agt), galanin (Gal), prolactin receptor (Prlr), and calcitonin receptor (Calcr). Potassium inwardly rectifying channel, subfamily J, member 6 (Kcnj6), and retinoic acid-related (RAR)-related orphan receptor alpha (Rora) were similarly differentially expressed between treatments across lines. Functional categories enriched among the genes presenting line-dependent amphetamine effect included genes coding for neuropeptides and associated with memory and neuroplasticity and synaptic signaling, energy, and redox processes. A line-dependent association between amphetamine exposure and the synaptic signaling genes neurogranin (Nrgn) and synaptic membrane exocytosis 1(Rims1) was highlighted in the gene networks. Our findings advance the understanding of molecular players and networks affected by amphetamine in support of the development of activity-targeted therapies that may capitalize on the benefits of this psychostimulant.
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Affiliation(s)
- Tassia M Goncalves
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bruce R Southey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Sandra L Rodriguez-Zas
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Lloyd CJ. The size accuracy of combination tests. AUST NZ J STAT 2017. [DOI: 10.1111/anzs.12197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chris J. Lloyd
- University of Melbourne; 200 Leicester Street Carlton VIC 3053 Australia
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Marzin T, Lorkowski G, Reule C, Rau S, Pabst E, Vester JC, Pabst H. Effects of a systemic enzyme therapy in healthy active adults after exhaustive eccentric exercise: a randomised, two-stage, double-blinded, placebo-controlled trial. BMJ Open Sport Exerc Med 2017; 2:e000191. [PMID: 28879033 PMCID: PMC5569274 DOI: 10.1136/bmjsem-2016-000191] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2017] [Indexed: 12/18/2022] Open
Abstract
Background Systemic enzyme therapy may improve symptoms of exhaustive eccentric exercise due to anti-inflammatory properties. Methods In a randomised, placebo-controlled, two-stage clinical trial, systemic enzyme therapy (Wobenzym) was administered for 72 hours before and 72 hours following a day on which subjects performed an exhaustive eccentric exercise (isokinetic loading of the quadriceps). Efficacy criteria (maximal strength and pain) and time points were selected to account for the multidimensional nature of exercise-induced muscle damage symptoms. Subjects were randomised in a crossover (stage I, n=28) and parallel group design (stage II, n=44). Results Analysis of stage I data demonstrated a significant superiority (Mann-Whitney=0.6153; p=0.0332; one sided) for systemic enzyme therapy compared with placebo. Stage II was designed as a randomised controlled parallel group comparison. Heterogeneity (I2>0.5) between stages led to separate analyses of stage I (endurance-trained subjects) and stage II (strength-trained subjects). Combined analysis resulted in no evidence for corresponding treatment effects. Analysis of pooled biomarker data, however, demonstrated significant favourable effects for systemic enzyme therapy in both stages. Conclusion Systemic enzyme therapy before and after exhaustive eccentric exercise resulted in higher maximal concentric strength in the less strength-trained subjects (stage I) and in significant favourable effects on biomarkers (inflammatory, metabolic and immune) in all subjects. The application of these findings needs further evaluation.
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Affiliation(s)
- Tobias Marzin
- Zentrum für Leistungsdiagnostik, Sportschule Fuerstenfeldbruck-Puch Gmbh, Fuerstenfeldbruck, Germany
| | | | | | - Stefanie Rau
- Mucos Pharma GmbH & Co. KG, Unterhaching, Germany
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Rufibach K, Chen M, Nguyen H. Comparison of different clinical development plans for confirmatory subpopulation selection. Contemp Clin Trials 2016; 47:78-84. [DOI: 10.1016/j.cct.2015.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/15/2015] [Accepted: 12/19/2015] [Indexed: 01/13/2023]
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Poon W, Vos P, Muresanu D, Vester J, von Wild K, Hömberg V, Wang E, Lee TMC, Matula C. Cerebrolysin Asian Pacific trial in acute brain injury and neurorecovery: design and methods. J Neurotrauma 2015; 32:571-80. [PMID: 25222349 DOI: 10.1089/neu.2014.3558] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the leading causes of injury-related death. In the United States alone, an estimated 1.7 million people sustain a TBI each year, and approximately 5.3 million people live with a TBI-related disability. The direct medical costs and indirect costs such as lost productivity of TBIs totaled an estimated $76.5 billion in the U.S. in the year 2000. Improving the limited treatment options for this condition remains challenging. However, recent reports from interdisciplinary working groups (consisting primarily of neurologists, neurosurgeons, neuropsychologists, and biostatisticians) have stated that to improve TBI treatment, important methodological lessons from the past must be taken into account in future clinical research. An evaluation of the neuroprotection intervention studies conducted over the last 30 years has indicated that a limited understanding of the underlying biological concepts and methodological design flaws are the major reasons for the failure of pharmacological agents to demonstrate efficacy. Cerebrolysin is a parenterally-administered neuro-peptide preparation that acts in a manner similar to endogenous neurotrophic factors. Cerebrolysin has a favorable adverse effect profile, and several meta-analyses have suggested that Cerebrolysin is beneficial as a dementia treatment. CAPTAIN is a randomized, double-blind, placebo-controlled, multi-center, multinational trial of the effects of Cerebrolysin on neuroprotection and neurorecovery after TBI using a multidimensional ensemble of outcome scales. The CAPTAIN trial will be the first TBI trial with a 'true' multidimensional approach based on full outcome scales, while avoiding prior weaknesses, such as loss of information through "dichotomization," or unrealistic assumptions such as "normal distribution."
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Affiliation(s)
- Wai Poon
- 1 Division of Neurosurgery, Prince of Wales Hospital, the Chinese University of Hong Kong , Hong Kong, China
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Lösch C, Neuhäuser M. The statistical analysis of a clinical trial when a protocol amendment changed the inclusion criteria. BMC Med Res Methodol 2008; 8:16. [PMID: 18397525 PMCID: PMC2359757 DOI: 10.1186/1471-2288-8-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2007] [Accepted: 04/08/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sometimes, protocol amendments that change the inclusion and exclusion criteria are required in clinical trials. Then, the patient populations before and after the amendment may differ. METHODS We propose to perform separate statistical tests for the different phases, i.e. for the patients recruited before and after the amendment, and to combine the tests using Fisher's combination test. After a significant combination test a multiple testing procedure can be applied to identify the phase(s) to which a proof of efficacy refers. We assume that the amendment(s) are not based on any type of unblinded data. The proposed method is investigated within a simulation study. RESULTS The proposed combination approach is superior to the 'naïve' strategy to ignore the differences between the phases and pooling the data to perform just one statistical test. This superiority disappears when there are hardly any differences between the two phases. CONCLUSION When one or more protocol amendments change the inclusion and exclusion criteria, one should realize that the populations may differ. In this case, separate tests for the different phases together with a combination test are a powerful method that can be applied in a variety of settings. The (first) amendment should specify the combination test to be applied in order to combine the different phases.
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Affiliation(s)
- Christian Lösch
- Institute for Medical Informatics, Biometry and Epidemiology, University of Duisburg-Essen, Hufelandstr, 55, 45122 Essen, Germany.
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Maïofiss-Dullin L, Boussac-Marlière N, Geffray B, Haimez C, Harriong S, Hitier S, Onado V. On the Efficiency of Interim Analyses Applied to Nonclinical Studies. ACTA ACUST UNITED AC 2007. [DOI: 10.1177/009286150704100410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
Adaptive test designs for clinical trials allow for a wide range of data driven design adaptations using all information gathered until an interim analysis. The basic principle is to use a test statistics which is invariant with respect to the design adaptations under the null hypothesis. This allows for a control of the type I error rate for the primary hypothesis even for adaptations not specified a priori in the study protocol. Estimation is usually another important part of a clinical trial, however, is more difficult in adaptive designs. In this research paper we give an overview of point and interval estimates for flexible designs and compare methods for typical sample size rules. We also make some proposals for confidence intervals which have nominal coverage probability also after an unforeseen design adaptation and which contain the maximum likelihood estimate and the usual unadjusted confidence interval.
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Affiliation(s)
- Werner Brannath
- Section of Medical Statistics, Core Unit for Medical Statistics and Informatics, Medical University of Vienna, Spitalgasse 23, A-1090 Wien, Austria.
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Abstract
Flexible designs for clinical trials permit mid-trial design modifications, which are based on interim information from inside or outside the trial while meeting (regulatory) requirements for the control of the type I error rate. The basic principle is to combine stage standardized test statistics such as p-values or z-scores in a pre-specified way. The flexibility covers changes of sample sizes, treatment allocation ratios and the number of interim analyses, as well as the selection of treatments, doses and end points. The price to be paid is that non-standard test statistics must be used after an adaptation.
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Affiliation(s)
- Peter Bauer
- Department of Medical Statistics University of Vienna, Schwarzspanierstr 17, A-1090 Vienna, Austria.
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Abstract
We outline the general framework of adaptive combination tests and discuss their relationship to flexible group sequential designs. An important field of applications is sample size reassessment. We discuss reassessment rules based on conditional power arguments using either the observed or the prefixed effect size. These rules tend to lead to large expected sample sizes for small actual effects. However, the application of a maximal bound for the second stage sample size leads to more favourable properties. Additionally, we consider an optimized reassessment rule in terms of expected sample sizes. Since the adaptive design does not use the classical test statistics for some types of sample size reassessments, the adaptive test may reject the null hypothesis while the classical one-sample test does not. We characterize sample size reassessment rules, where such inconsistencies are avoided. Finally, the extension of flexibility to the number of stages is explored. In the first interim analysis a second interim analysis is only planned if the chance to achieve a decision there is high. This leads to savings in the average number of interim analysis performed, without paying a noticeable price in terms of expected sample size.
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Affiliation(s)
- Martin Posch
- Department of Medical Statistics, University of Vienna, Schwarzspanierstrasse 17, A-1090 Wien, Austria
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Abstract
A general method is presented integrating the concept of adaptive interim analyses into classical group sequential testing. This allows the researcher to represent every group sequential plan as an adaptive trial design and to make design changes during the course of the trial after every interim analysis in the same way as with adaptive designs. The concept of adaptive trial designing is thereby generalized to a large variety of possible sequential plans.
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Affiliation(s)
- H H Müller
- Institute of Medical Biometry and Epidemiology, Philipps-University of Marburg, Germany.
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Abstract
A method for group sequential trials that is based on the inverse normal method for combining the results of the separate stages is proposed. Without exaggerating the Type I error rate, this method enables data-driven sample size reassessments during the course of the study. It uses the stopping boundaries of the classical group sequential tests. Furthermore, exact test procedures may be derived for a wide range of applications. The procedure is compared with the classical designs in terms of power and expected sample size.
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Affiliation(s)
- W Lehmacher
- Institut für Medizinische Statistik, Informatik und Epidemiologie, Universität zu Köln, Germany.
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Abstract
In the development of medical treatments, identification of promising therapies and inference on selected treatments are usually performed in subsequent separate trials. An adaptive two-stage design is proposed for the situation of multiple treatments to be compared with a control, allowing integration of both steps within a single confirmatory trial controlling the multiple level alpha. After the interim analysis, the trial may be terminated early or is continued with a second stage, where the set of treatments may be reduced due to lack of efficacy or to safety problems. The procedure is highly flexible with respect to the distributional assumptions, stopping rules and selection criteria and allows a completely free recalculation of the sample size for the second stage. Simulations show that the method may be substantially more powerful than classical one-stage multiple treatment designs with the same total sample size. As in conventional strategies with a series of separate experiments, a reasonable selection strategy has to be applied in order to prevent proceeding with non-optimal treatments.
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Affiliation(s)
- P Bauer
- Institute of Medical Statistics, University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
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