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  1. Article ; Online: Treatment success in pragmatic randomised controlled trials

    Raftery James / Dent Louise

    Trials, Vol 12, Iss 1, p

    a review of trials funded by the UK Health Technology Assessment programme

    2011  Volume 109

    Abstract: Abstract Background Previous research reviewed treatment success and whether the collective uncertainty principle is met in RCTs in the US National Cancer Institute portfolio. This paper classifies clinical trials funded by the UK HTA programme by ... ...

    Abstract Abstract Background Previous research reviewed treatment success and whether the collective uncertainty principle is met in RCTs in the US National Cancer Institute portfolio. This paper classifies clinical trials funded by the UK HTA programme by results using the method applied to the US Cancer Institute trials, and compares the two portfolios. Methods Data on all completed randomised controlled trials funded by the HTA programme 1993-2008 were extracted. Each trial's primary results was classified into six categories; 1) statistically significant in favour of the new treatment, 2) statistically significant in favour of the control treatment 3) true negative, 4) truly inconclusive, 5) inconclusive in favour of new treatment or 6) inconclusive in favour of control treatment. Trials were classified by comparing the 95% confidence interval for the difference in primary outcome to the difference specified in the sample size calculation. The results were compared with Djulbegovic's analysis of NCI trials. Results Data from 51 superiority trials were included, involving over 48,000 participants and a range of diseases and interventions. 85 primary comparisons were available because some trials had more than two randomised arms or had several primary outcomes. The new treatment had superior results (whether significant or not) in 61% of the comparisons (52/85 95% CI 49.9% to 71.6%). The results were conclusive in 46% of the comparisons (19% statistically significant in favour of the new treatment, 5% statistically significant in favour of the control and 22% true negative). The results were classified as truly inconclusive (i.e. failed to answer the question asked) for 24% of comparisons (20/85). HTA trials included fewer truly inconclusive and statistically significant results and more results rated as true negative than NCI trials. Conclusions The pattern of results in HTA trials is similar to that of the National Cancer Institute portfolio. Differences that existed were plausible given the differences in the types ...
    Keywords Medicine (General) ; R5-920
    Subject code 610
    Language English
    Publishing date 2011-05-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Treatment success in pragmatic randomised controlled trials

    Dent Louise / Raftery James

    Trials, Vol 12, Iss Suppl 1, p A

    a review of trials funded by the UK Health Technology Assessment programme

    2011  Volume 97

    Keywords Medicine (General) ; R5-920
    Language English
    Publishing date 2011-12-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Treatment success in pragmatic randomised controlled trials: a review of trials funded by the UK Health Technology Assessment programme.

    Dent, Louise / Raftery, James

    Trials

    2011  Volume 12, Page(s) 109

    Abstract: Background: Previous research reviewed treatment success and whether the collective uncertainty principle is met in RCTs in the US National Cancer Institute portfolio. This paper classifies clinical trials funded by the UK HTA programme by results using ...

    Abstract Background: Previous research reviewed treatment success and whether the collective uncertainty principle is met in RCTs in the US National Cancer Institute portfolio. This paper classifies clinical trials funded by the UK HTA programme by results using the method applied to the US Cancer Institute trials, and compares the two portfolios.
    Methods: Data on all completed randomised controlled trials funded by the HTA programme 1993-2008 were extracted. Each trial's primary results was classified into six categories; 1) statistically significant in favour of the new treatment, 2) statistically significant in favour of the control treatment 3) true negative, 4) truly inconclusive, 5) inconclusive in favour of new treatment or 6) inconclusive in favour of control treatment. Trials were classified by comparing the 95% confidence interval for the difference in primary outcome to the difference specified in the sample size calculation. The results were compared with Djulbegovic's analysis of NCI trials.
    Results: Data from 51 superiority trials were included, involving over 48,000 participants and a range of diseases and interventions. 85 primary comparisons were available because some trials had more than two randomised arms or had several primary outcomes. The new treatment had superior results (whether significant or not) in 61% of the comparisons (52/85 95% CI 49.9% to 71.6%). The results were conclusive in 46% of the comparisons (19% statistically significant in favour of the new treatment, 5% statistically significant in favour of the control and 22% true negative). The results were classified as truly inconclusive (i.e. failed to answer the question asked) for 24% of comparisons (20/85). HTA trials included fewer truly inconclusive and statistically significant results and more results rated as true negative than NCI trials.
    Conclusions: The pattern of results in HTA trials is similar to that of the National Cancer Institute portfolio. Differences that existed were plausible given the differences in the types of trials -HTA trials are more pragmatic. The results indicate HTA trials are compatible with equipoise. This classification usefully summarises the results from clinical trials and enables comparisons of different portfolios of trials.
    MeSH term(s) Biomedical Technology/economics ; Evidence-Based Medicine/classification ; Evidence-Based Medicine/economics ; Humans ; National Cancer Institute (U.S.) ; Randomized Controlled Trials as Topic/classification ; Randomized Controlled Trials as Topic/economics ; Research Design ; Research Support as Topic ; Risk Assessment ; Terminology as Topic ; Therapeutic Equipoise ; Treatment Outcome ; United Kingdom ; United States
    Language English
    Publishing date 2011-05-04
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 2040523-6
    ISSN 1745-6215 ; 1468-6694 ; 1745-6215
    ISSN (online) 1745-6215
    ISSN 1468-6694 ; 1745-6215
    DOI 10.1186/1745-6215-12-109
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Junior researchers' experience of innovation in a multidisciplinary team environment

    Seto, Iva / Dent, Louise

    Knowledge management research & practice : KMRP ; a journal of the OR Society Vol. 9, No. 1 , p. 95-97

    2011  Volume 9, Issue 1, Page(s) 95–97

    Author's details Iva Seto and Louise Dent
    Language English
    Publisher Palgrave Macmillan
    Publishing place Basingstoke
    Document type Article
    ZDB-ID 2116287-6
    ISSN 1477-8238
    Database ECONomics Information System

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  5. Article ; Online: "Flogging dead horses"

    Jolly Kate / Taylor Rod / Dent Louise / Raftery James

    Trials, Vol 12, Iss 1, p

    evaluating when have clinical trials achieved sufficiency and stability? A case study in cardiac rehabilitation

    2011  Volume 83

    Abstract: Abstract Background Most systematic reviews conclude that another clinical trial is needed. Measures of sufficiency and stability may indicate whether this is true. Objectives: To show how evidence accumulated on centre-based versus home-based cardiac ... ...

    Abstract Abstract Background Most systematic reviews conclude that another clinical trial is needed. Measures of sufficiency and stability may indicate whether this is true. Objectives: To show how evidence accumulated on centre-based versus home-based cardiac rehabilitation, including estimates of sufficiency and stability Methods Systematic reviews of clinical trials of home versus centre-based cardiac rehabilitation were used to develop a cumulative meta-analysis over time. We calculated the standardised mean difference (SMD) in effect, confidence intervals and indicators of sufficiency and stability. Sufficiency refers to whether the meta-analytic database adequately demonstrates that an intervention works - is statistically superior to another. It does this by assessing the number of studies with null results that would be required to make the meta-analytic effect non-statistically significant. Stability refers to whether the direction and size of the effect is stable as new studies are added to the meta-analysis. Results The standardised mean effect difference reduced over fourteen comparisons from a non-significant difference favouring home-based cardiac rehabilitation to a very small difference favouring hospital (SMD -0.10, 95% CI -0.32 to 0.13). This difference did not reach the sufficiency threshold (failsafe ratio 0.039 < 1) but did achieve the criteria for stability (cumulative slope 0.003 < 0.005). Conclusions The evidence points to a relatively small effect difference which was stable but not sufficient in terms of the suggested thresholds. Sufficiency should arguably be based on substantive significance and decided by patients. Research on patient preferences should be the priority. Sufficiency and stability measures are useful tools that need to be tested in further case studies.
    Keywords Medicine (General) ; R5-920
    Language English
    Publishing date 2011-03-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: A systematic review of models to predict recruitment to multicentre clinical trials

    Cook Andrew / Dent Louise / Barnard Katharine D

    BMC Medical Research Methodology, Vol 10, Iss 1, p

    2010  Volume 63

    Abstract: Abstract Background Less than one third of publicly funded trials managed to recruit according to their original plan often resulting in request for additional funding and/or time extensions. The aim was to identify models which might be useful to a ... ...

    Abstract Abstract Background Less than one third of publicly funded trials managed to recruit according to their original plan often resulting in request for additional funding and/or time extensions. The aim was to identify models which might be useful to a major public funder of randomised controlled trials when estimating likely time requirements for recruiting trial participants. The requirements of a useful model were identified as usability, based on experience, able to reflect time trends, accounting for centre recruitment and contribution to a commissioning decision. Methods A systematic review of English language articles using MEDLINE and EMBASE. Search terms included: randomised controlled trial, patient, accrual, predict, enrol, models, statistical; Bayes Theorem; Decision Theory; Monte Carlo Method and Poisson. Only studies discussing prediction of recruitment to trials using a modelling approach were included. Information was extracted from articles by one author, and checked by a second, using a pre-defined form. Results Out of 326 identified abstracts, only 8 met all the inclusion criteria. Of these 8 studies examined, there are five major classes of model discussed: the unconditional model, the conditional model, the Poisson model, Bayesian models and Monte Carlo simulation of Markov models. None of these meet all the pre-identified needs of the funder. Conclusions To meet the needs of a number of research programmes, a new model is required as a matter of importance. Any model chosen should be validated against both retrospective and prospective data, to ensure the predictions it gives are superior to those currently used.
    Keywords Medicine (General) ; R5-920
    Subject code 310
    Language English
    Publishing date 2010-07-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: "Flogging dead horses": evaluating when have clinical trials achieved sufficiency and stability? A case study in cardiac rehabilitation.

    Dent, Louise / Taylor, Rod / Jolly, Kate / Raftery, James

    Trials

    2011  Volume 12, Page(s) 83

    Abstract: Background: Most systematic reviews conclude that another clinical trial is needed. Measures of sufficiency and stability may indicate whether this is true.: Objectives: To show how evidence accumulated on centre-based versus home-based cardiac ... ...

    Abstract Background: Most systematic reviews conclude that another clinical trial is needed. Measures of sufficiency and stability may indicate whether this is true.
    Objectives: To show how evidence accumulated on centre-based versus home-based cardiac rehabilitation, including estimates of sufficiency and stability
    Methods: Systematic reviews of clinical trials of home versus centre-based cardiac rehabilitation were used to develop a cumulative meta-analysis over time. We calculated the standardised mean difference (SMD) in effect, confidence intervals and indicators of sufficiency and stability. Sufficiency refers to whether the meta-analytic database adequately demonstrates that an intervention works - is statistically superior to another. It does this by assessing the number of studies with null results that would be required to make the meta-analytic effect non-statistically significant. Stability refers to whether the direction and size of the effect is stable as new studies are added to the meta-analysis.
    Results: The standardised mean effect difference reduced over fourteen comparisons from a non-significant difference favouring home-based cardiac rehabilitation to a very small difference favouring hospital (SMD -0.10, 95% CI -0.32 to 0.13). This difference did not reach the sufficiency threshold (failsafe ratio 0.039<1) but did achieve the criteria for stability (cumulative slope 0.003<0.005).
    Conclusions: The evidence points to a relatively small effect difference which was stable but not sufficient in terms of the suggested thresholds. Sufficiency should arguably be based on substantive significance and decided by patients. Research on patient preferences should be the priority. Sufficiency and stability measures are useful tools that need to be tested in further case studies.
    MeSH term(s) Clinical Trials as Topic/statistics & numerical data ; Community Health Services/statistics & numerical data ; Data Interpretation, Statistical ; Evidence-Based Medicine/statistics & numerical data ; Heart Diseases/rehabilitation ; Home Care Services/statistics & numerical data ; Humans ; Outpatient Clinics, Hospital/statistics & numerical data ; Research Design ; Treatment Outcome
    Language English
    Publishing date 2011-03-21
    Publishing country England
    Document type Journal Article ; Meta-Analysis ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2040523-6
    ISSN 1745-6215 ; 1468-6694 ; 1745-6215
    ISSN (online) 1745-6215
    ISSN 1468-6694 ; 1745-6215
    DOI 10.1186/1745-6215-12-83
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: What are the characteristics of an application (or team) which are associated with success or failure of an application to the NIHR HTA programme for research funding?

    Turner Sheila / Davidson Peter / Dent Louise / Streit Elke / Bowness Victoria

    Trials, Vol 12, Iss Suppl 1, p A

    2011  Volume 58

    Keywords Diseases of the circulatory (Cardiovascular) system ; RC666-701 ; Specialties of internal medicine ; RC581-951 ; Internal medicine ; RC31-1245 ; Medicine ; R ; DOAJ:Cardiovascular ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2011-12-01T00:00:00Z
    Publisher BioMed Central
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: A systematic review of models to predict recruitment to multicentre clinical trials.

    Barnard, Katharine D / Dent, Louise / Cook, Andrew

    BMC medical research methodology

    2010  Volume 10, Page(s) 63

    Abstract: Background: Less than one third of publicly funded trials managed to recruit according to their original plan often resulting in request for additional funding and/or time extensions. The aim was to identify models which might be useful to a major ... ...

    Abstract Background: Less than one third of publicly funded trials managed to recruit according to their original plan often resulting in request for additional funding and/or time extensions. The aim was to identify models which might be useful to a major public funder of randomised controlled trials when estimating likely time requirements for recruiting trial participants. The requirements of a useful model were identified as usability, based on experience, able to reflect time trends, accounting for centre recruitment and contribution to a commissioning decision.
    Methods: A systematic review of English language articles using MEDLINE and EMBASE. Search terms included: randomised controlled trial, patient, accrual, predict, enroll, models, statistical; Bayes Theorem; Decision Theory; Monte Carlo Method and Poisson. Only studies discussing prediction of recruitment to trials using a modelling approach were included. Information was extracted from articles by one author, and checked by a second, using a pre-defined form.
    Results: Out of 326 identified abstracts, only 8 met all the inclusion criteria. Of these 8 studies examined, there are five major classes of model discussed: the unconditional model, the conditional model, the Poisson model, Bayesian models and Monte Carlo simulation of Markov models. None of these meet all the pre-identified needs of the funder.
    Conclusions: To meet the needs of a number of research programmes, a new model is required as a matter of importance. Any model chosen should be validated against both retrospective and prospective data, to ensure the predictions it gives are superior to those currently used.
    MeSH term(s) Bayes Theorem ; Humans ; Models, Statistical ; Monte Carlo Method ; Multicenter Studies as Topic ; Patient Selection ; Poisson Distribution ; Randomized Controlled Trials as Topic ; Time Factors
    Language English
    Publishing date 2010-07-06
    Publishing country England
    Document type Journal Article ; Review ; Systematic Review
    ISSN 1471-2288
    ISSN (online) 1471-2288
    DOI 10.1186/1471-2288-10-63
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Registration of noncommercial randomised clinical trials

    Raftery James / Fairbank Eleanor / Douet Lisa / Dent Louise / Price Alison / Milne Ruairidh / Walley Tom

    Trials, Vol 13, Iss 1, p

    the feasibility of using trial registries to monitor the number of trials

    2012  Volume 140

    Abstract: Abstract Background A 2003 survey suggested the number of noncommercial trials in the UK was declining. Formation of the NIHR in 2006 and increased research spending by the Department of Health may have increased the number of noncommercial trials but no ...

    Abstract Abstract Background A 2003 survey suggested the number of noncommercial trials in the UK was declining. Formation of the NIHR in 2006 and increased research spending by the Department of Health may have increased the number of noncommercial trials but no data are available. Methods Available data on UK noncommercial trials (were obtained from the two relevant registries: ISRCTN register for the UK, and US ClinicalTrials.gov. Data on each trial were sorted by start year, and compared with the: 2003 survey, and UKCRN portfolio database from 2007. Results The number of UK noncommercial trials registered rose from 25 in 1990 to 188 in 1999, peaked at 533 in 2003, and fell back to 334 in 2009. Total trials registered was similar to but slightly above those in the 2003 survey up to 1998, then rose sharply to 2002 before falling to 2007. From 2007 to 2009 the number registered to start each year was similar to but slightly above the UKCRN database. Less than 10% of UK noncommercial trials registered with ClinGov for most years before 2005, but this rose to 35% by 2009. Conclusions For the periods of overlap, trial registration data provide fairly similar totals to other sources on the number of noncommercial trials starting each year. The rise and fall in the number of trials registered between 1999 and 2007 was due to those registered in the ISRCTN database as funded by NHS Trusts. After 2007, the number of trials registered as funded by NHS Trusts has fallen in the ISRCTN register but these trials may have migrated to the US ClinGov register. The total number of noncommercial trial starts, excluding those funded by NHS Trusts, has been upward since around 2002. By 2009 the two main funders were NIHR and charities. Feasibility of using registration data to monitor the number of noncommercial trials has been demonstrated but is complicated by the use of two registers and difficulties in accessing the data. We recommend an annual report on the number of noncommercial trials registering each year.
    Keywords Trial registration ; Noncommercial randomised clinical trials ; Medicine (General) ; R5-920
    Subject code 610
    Language English
    Publishing date 2012-08-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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