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  1. Article ; Online: The design and analysis of vaccine trials for COVID-19 for the purpose of estimating efficacy.

    Senn, Stephen

    Pharmaceutical statistics

    2022  Volume 21, Issue 4, Page(s) 790–807

    Abstract: ... AstraZeneca/Oxford University, Moderna, Novavax and J&J Janssen are considered briefly. Frequentist approaches ...

    Abstract After a preliminary explanation as to how I came to know Andy Grieve and some remarks about his career and mine and how they have intersected, I consider the design and analysis of trials of vaccines for COVID-19 for the purpose of estimating efficacy. Five large trials, run by the sponsors Pfizer/BioNTech, AstraZeneca/Oxford University, Moderna, Novavax and J&J Janssen are considered briefly. Frequentist approaches to analysis were used for four of the trials but Pfizer/BioNTech nominated a Bayesian approach. The design and analysis of this trial is considered in some detail, in particular as regards the choice of prior distribution. I conclude by drawing some general lessons.
    MeSH term(s) Bayes Theorem ; COVID-19/prevention & control ; COVID-19 Vaccines ; Humans
    Chemical Substances COVID-19 Vaccines
    Language English
    Publishing date 2022-07-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2083706-9
    ISSN 1539-1612 ; 1539-1604
    ISSN (online) 1539-1612
    ISSN 1539-1604
    DOI 10.1002/pst.2226
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  2. Article ; Online: Treatment Effects in Multicenter Randomized Clinical Trials.

    Senn, Stephen J / Lewis, Roger J

    JAMA

    2019  Volume 321, Issue 12, Page(s) 1211–1212

    MeSH term(s) Antibodies, Monoclonal ; Humans ; Migraine Disorders ; Randomized Controlled Trials as Topic ; Research Design
    Chemical Substances Antibodies, Monoclonal ; fremanezumab
    Language English
    Publishing date 2019-03-01
    Publishing country United States
    Document type Journal Article ; Comment
    ZDB-ID 2958-0
    ISSN 1538-3598 ; 0254-9077 ; 0002-9955 ; 0098-7484
    ISSN (online) 1538-3598
    ISSN 0254-9077 ; 0002-9955 ; 0098-7484
    DOI 10.1001/jama.2019.1480
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  3. Article ; Online: Implementing Historical Controls in Oncology Trials.

    Collignon, Olivier / Schritz, Anna / Spezia, Riccardo / Senn, Stephen J

    The oncologist

    2021  Volume 26, Issue 5, Page(s) e859–e862

    Abstract: Drug development in oncology has broadened from mainly considering randomized clinical trials to also including single-arm trials tailored for very specific subtypes of cancer. They often use historical controls, and this article discusses benefits and ... ...

    Abstract Drug development in oncology has broadened from mainly considering randomized clinical trials to also including single-arm trials tailored for very specific subtypes of cancer. They often use historical controls, and this article discusses benefits and risks of this paradigm and provide various regulatory and statistical considerations. While leveraging the information brought by historical controls could potentially shorten development time and reduce the number of patients enrolled, a careful selection of the past studies, a prespecified statistical analysis accounting for the heterogeneity between studies, and early engagement with regulators will be key to success. Although both the European Medicines Agency and the U.S. Food and Drug Administration have already approved medicines based on nonrandomized experiments, the evidentiary package can be perceived as less comprehensive than randomized experiments. Use of historical controls, therefore, is better suited for cases of high unmet clinical need, where the disease course is well characterized and the primary endpoint is objective. IMPLICATIONS FOR PRACTICE: Incorporating historical data in single-arm oncology trials has the potential to accelerate drug development and to reduce the number of patients enrolled, compared with standard randomized controlled clinical trials. Given the lack of blinding and randomization, such an approach is better suited for cases of high unmet clinical need and/or difficult experimental situations, in which the trajectory of the disease is well characterized and the endpoint can be measured objectively. Careful pre-specification and selection of the historical data, matching of the patient characteristics with the concurrent trial data, and innovative statistical methodologies accounting for between-study variation will be needed. Early engagement with regulators (e.g., via Scientific Advice) is highly recommended.
    MeSH term(s) Humans ; Medical Oncology ; Neoplasms/drug therapy ; Research Design
    Language English
    Publishing date 2021-03-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1409038-7
    ISSN 1549-490X ; 1083-7159
    ISSN (online) 1549-490X
    ISSN 1083-7159
    DOI 10.1002/onco.13696
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  4. Article: Controlling multiple orderings in metal thiocyanate molecular perovskites A

    Lee, Jie Yie / Ling, Sanliang / Argent, Stephen P / Senn, Mark S / Cañadillas-Delgado, Laura / Cliffe, Matthew J

    Chemical science

    2021  Volume 12, Issue 10, Page(s) 3516–3525

    Abstract: We report four new A-site vacancy ordered thiocyanate double double perovskites, , A = ... ...

    Abstract We report four new A-site vacancy ordered thiocyanate double double perovskites, , A = K
    Language English
    Publishing date 2021-01-15
    Publishing country England
    Document type Journal Article
    ZDB-ID 2559110-1
    ISSN 2041-6539 ; 2041-6520
    ISSN (online) 2041-6539
    ISSN 2041-6520
    DOI 10.1039/d0sc06619b
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  5. Article ; Online: Clustered allocation as a way of understanding historical controls: Components of variation and regulatory considerations.

    Collignon, Olivier / Schritz, Anna / Senn, Stephen J / Spezia, Riccardo

    Statistical methods in medical research

    2019  Volume 29, Issue 7, Page(s) 1960–1971

    Abstract: There has been increasing interest in recent years in the possibility of increasing the efficiency of clinical trials by using historical controls. There has been a general recognition that in replacing concurrent by historical controls, the potential ... ...

    Abstract There has been increasing interest in recent years in the possibility of increasing the efficiency of clinical trials by using historical controls. There has been a general recognition that in replacing concurrent by historical controls, the potential for bias is serious and requires some down-weighting to the apparent amount of historical information available. However, such approaches have generally assumed that what is required is some modification to the standard inferential model offered by the parallel group trial. In our opinion, the correct starting point that requires modification is a trial in which treatments are allocated to clusters. This immediately shows that the amount of information available is governed not just by the number of historical patients but also by the number of centres and of historical studies. Furthermore, once one accepts that external patients may be used as controls, this raises the issue as to which patients should be used. Thus, abandoning concurrent control has implications for many aspects of design and analysis of trials, including (a) identification, pre-specification and agreement on a suitable historical dataset; (b) an agreed, enforceable and checkable plan for recruiting the experimental arm; (c) a finalised analysis plan prior to beginning the trial and (d) use of a hierarchical model with sufficient complexity. We discuss these issues and suggest approaches to design and analysis making extensive reference to the partially randomised Therapeutic Arthritis Research and Gastrointestinal Event Trial study. We also compare some Bayesian and frequentist approaches and provide some important regulatory considerations. We conclude that effective use of historical data will require considerable circumspection and discipline.
    MeSH term(s) Bayes Theorem ; Bias ; Humans ; Research Design
    Language English
    Publishing date 2019-10-10
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1136948-6
    ISSN 1477-0334 ; 0962-2802
    ISSN (online) 1477-0334
    ISSN 0962-2802
    DOI 10.1177/0962280219880213
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  6. Article ; Online: Overstating the evidence: double counting in meta-analysis and related problems.

    Senn, Stephen J

    BMC medical research methodology

    2009  Volume 9, Page(s) 10

    Abstract: Background: The problem of missing studies in meta-analysis has received much attention. Less attention has been paid to the more serious problem of double counting of evidence.: Methods: Various problems in overstating the precision of results from ... ...

    Abstract Background: The problem of missing studies in meta-analysis has received much attention. Less attention has been paid to the more serious problem of double counting of evidence.
    Methods: Various problems in overstating the precision of results from meta-analyses are described and illustrated with examples, including papers from leading medical journals. These problems include, but are not limited to, simple double counting of the same studies, double counting of some aspects of the studies, inappropriate imputation of results, and assigning spurious precision to individual studies.
    Results: Some suggestions are made as to how the quality and reliability of meta-analysis can be improved. It is proposed that the key to quality in meta-analysis lies in the results being transparent and checkable.
    Conclusion: Existing quality check lists for meta-analysis do little to encourage an appropriate attitude to combining evidence and to statistical analysis. Journals and other relevant organisations should encourage authors to make data available and make methods explicit. They should also act promptly to withdraw meta-analyses when mistakes are found.
    MeSH term(s) Clinical Trials as Topic ; Data Interpretation, Statistical ; Humans ; Meta-Analysis as Topic ; Methods ; Randomized Controlled Trials as Topic ; Review Literature as Topic
    Language English
    Publishing date 2009-02-13
    Publishing country England
    Document type Journal Article ; Review
    ISSN 1471-2288
    ISSN (online) 1471-2288
    DOI 10.1186/1471-2288-9-10
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  7. Article ; Online: Pronounced interplay between intrinsic phase-coexistence and octahedral tilt magnitude in hole-doped lanthanum cuprates.

    Tidey, Jeremiah P / Liu, En-Pei / Lai, Yen-Chung / Chuang, Yu-Chun / Chen, Wei-Tin / Cane, Lauren J / Lester, Chris / Petsch, Alexander N D / Herlihy, Anna / Simonov, Arkadiy / Hayden, Stephen M / Senn, Mark

    Scientific reports

    2022  Volume 12, Issue 1, Page(s) 14343

    Abstract: Definitive understanding of superconductivity and its interplay with structural symmetry in the hole-doped lanthanum cuprates remains elusive. The suppression of superconductivity around 1/8th doping maintains particular focus, often attributed to charge- ...

    Abstract Definitive understanding of superconductivity and its interplay with structural symmetry in the hole-doped lanthanum cuprates remains elusive. The suppression of superconductivity around 1/8th doping maintains particular focus, often attributed to charge-density waves (CDWs) ordering in the low-temperature tetragonal (LTT) phase. Central to many investigations into this interplay is the thesis that La
    Language English
    Publishing date 2022-08-22
    Publishing country England
    Document type Journal Article
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-022-18574-1
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  8. Article ; Online: Synthesis of fused tricyclic systems by thermal Cope rearrangement of furan-substituted vinyl cyclopropanes.

    Klaus, Verena / Wittmann, Stéphane / Senn, Hans M / Clark, J Stephen

    Organic & biomolecular chemistry

    2018  Volume 16, Issue 21, Page(s) 3970–3982

    Abstract: A novel method for the stereoselective construction of hexahydroazuleno[4,5-b]furans from simple precursors has been developed. The route involves the use of our recently developed Brønsted acid catalysed cyclisation reaction of acyclic ynenones to ... ...

    Abstract A novel method for the stereoselective construction of hexahydroazuleno[4,5-b]furans from simple precursors has been developed. The route involves the use of our recently developed Brønsted acid catalysed cyclisation reaction of acyclic ynenones to prepare fused 1-furanyl-2-alkenylcyclopropanes that undergo highly stereoselective thermal Cope rearrangement to produce fused tricyclic products. Substrates possessing an E-alkene undergo smooth Cope rearrangement at 40 °C, whereas the corresponding Z-isomers do not react at this temperature. Computational studies have been performed to explain the difference in behaviour of the E- and Z-isomers in the Cope rearrangement reaction. The hexahydroazuleno[4,5-b]furans produced by Cope rearrangement have potential as advanced intermediates for the synthesis of members of the guaianolide family of natural products.
    Language English
    Publishing date 2018-05-14
    Publishing country England
    Document type Journal Article
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/c8ob00924d
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  9. Article ; Online: JAMA's policy does not go far enough.

    Senn, Stephen J

    BMJ (Clinical research ed.)

    2006  Volume 332, Issue 7536, Page(s) 305

    MeSH term(s) Editorial Policies ; Periodicals as Topic ; United States
    Language English
    Publishing date 2006-02-04
    Publishing country England
    Document type Comment ; Letter
    ZDB-ID 1362901-3
    ISSN 1756-1833 ; 0959-8154 ; 0959-8146 ; 0959-8138 ; 0959-535X ; 1759-2151
    ISSN (online) 1756-1833
    ISSN 0959-8154 ; 0959-8146 ; 0959-8138 ; 0959-535X ; 1759-2151
    DOI 10.1136/bmj.332.7536.305-a
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  10. Article ; Online: Turning a blind eye: authors have blinkered view of blinding.

    Senn, Stephen J

    BMJ (Clinical research ed.)

    2004  Volume 328, Issue 7448, Page(s) 1135–6; author reply 1136

    MeSH term(s) Double-Blind Method ; Randomized Controlled Trials as Topic/standards
    Language English
    Publishing date 2004-05-08
    Publishing country England
    Document type Comment ; Letter
    ZDB-ID 1362901-3
    ISSN 1756-1833 ; 0959-8154 ; 0959-8146 ; 0959-8138 ; 0959-535X ; 1759-2151
    ISSN (online) 1756-1833
    ISSN 0959-8154 ; 0959-8146 ; 0959-8138 ; 0959-535X ; 1759-2151
    DOI 10.1136/bmj.328.7448.1135-b
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