221 research outputs found

    Neurological Complications and MRI

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    Cerebrovascular diseases (cerebral infarction, intracranial haemorrhage and vasculopathy) are common manifestations of sickle cell disease (SCD) associated with significant morbidity and mortality. These neurological complications and potential corresponding neuropsychological compromise may have devastating consequences for a child with SCD. This chapter aims to review the neurological complications in SCD using magnetic resonance imaging (MRI) as both a qualitative and a quantitative tool for detecting abnormality. Advanced MRI pulse sequences, such as high-resolution 3D T1-weighted imaging for brain volumetrics, diffusion tensor imaging for white matter integrity and non-invasive perfusion MRI for cerebral blood flow (CBF) measurement, can provide additional information about the structure and function of brain tissue beyond the scope of conventional clinical imaging. These studies have set to establish quantitative biomarkers that relate to disease severity and neuropsychological sequelae

    Bias Due to Changes in Specified Outcomes during the Systematic Review Process

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    Background Adding, omitting or changing outcomes after a systematic review protocol is published can result in bias because it increases the potential for unacknowledged or post hoc revisions of the planned analyses. The main objective of this study was to look for discrepancies between primary outcomes listed in protocols and in the subsequent completed reviews published on the Cochrane Library. A secondary objective was to quantify the risk of bias in a set of meta-analyses where discrepancies between outcome specifications in protocols and reviews were found. Methods and Findings New reviews from three consecutive issues of the Cochrane Library were assessed. For each review, the primary outcome(s) listed in the review protocol and the review itself were identified and review authors were contacted to provide reasons for any discrepancies. Over a fifth (64/288, 22%) of protocol/review pairings were found to contain a discrepancy in at least one outcome measure, of which 48 (75%) were attributable to changes in the primary outcome measure. Where lead authors could recall a reason for the discrepancy in the primary outcome, there was found to be potential bias in nearly a third (8/28, 29%) of these reviews, with changes being made after knowledge of the results from individual trials. Only 4(6%) of the 64 reviews with an outcome discrepancy described the reason for the change in the review, with no acknowledgment of the change in any of the eight reviews containing potentially biased discrepancies. Outcomes that were promoted in the review were more likely to be significant than if there was no discrepancy (relative risk 1.66 95% CI (1.10, 2.49), p = 0.02). Conclusion In a review, making changes after seeing the results for included studies can lead to biased and misleading interpretation if the importance of the outcome (primary or secondary) is changed on the basis of those results. Our assessment showed that reasons for discrepancies with the protocol are not reported in the review, demonstrating an under-recognition of the problem. Complete transparency in the reporting of changes in outcome specification is vital; systematic reviewers should ensure that any legitimate changes to outcome specification are reported with reason in the review

    Outcome measures in rheumatoid arthritis randomised trials over the last 50 years

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    BACKGROUND: The development and application of standardised sets of outcomes to be measured and reported in clinical trials have the potential to increase the efficiency and value of research. One of the most notable of the current outcome sets began nearly 20 years ago: the World Health Organization and International League of Associations for Rheumatology core set of outcomes for rheumatoid arthritis clinical trials, originating from the OMERACT (Outcome Measures in Rheumatology) Initiative. This study assesses the use of this core outcome set by randomised trials in rheumatology. METHODS: An observational review was carried out of 350 randomised trials for the treatment of rheumatoid arthritis identified through The Cochrane Library (up to and including September 2012 issue). Reports of these trials were evaluated to determine whether or not there were trends in the proportion of trials reporting on the full set of core outcomes over time. Researchers who conducted trials after the publication of the core set were contacted to assess their awareness of it and to collect reasons for non-inclusion of the full core set of outcomes in the study. RESULTS: Since the introduction of the core set of outcomes for rheumatoid arthritis, the consistency of measurement of the core set of outcomes has improved, although variation in the choice of measurement instrument remains. The majority of trialists who responded said that they would consider using the core outcome set in the design of a new trial. CONCLUSIONS: This observational review suggests that a higher percentage of trialists conducting trials in rheumatoid arthritis are now measuring the rheumatoid arthritis core outcome set. Core outcome sets have the potential to improve the evidence base for health care, but consideration must be given to the methods for disseminating their availability amongst the relevant communities

    Interventions to improve adherence to reporting guidelines in health research: a scoping review protocol

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    Introduction There is evidence that the use of some reporting guidelines, such as the Consolidated Standards for Reporting Trials, is associated with improved completeness of reporting in health research. However, the current levels of adherence to reporting guidelines are suboptimal. Over the last few years, several actions aiming to improve compliance with reporting guidelines have been taken and proposed. We will conduct a scoping review of interventions to improve adherence to reporting guidelines in health research that have been evaluated or suggested, in order to inform future interventions. Methods and analysis Our review will follow the Joanna Briggs Institute scoping review methods manual. We will search for relevant studies in MEDLINE, EMBASE and Cochrane Library databases. Moreover, we will carry out lateral searches from the reference lists of the included studies, as well as from the lists of articles citing the included ones. One reviewer will screen the full list, which will be randomly split into two halves and independently screened by the other two reviewers. Two reviewers will perform data extraction independently. Discrepancies will be solved through discussion. In addition, this search strategy will be supplemented by a grey literature search. The interventions found will be classified as assessed or suggested, as well as according to different criteria, in relation to their target (journal policies, journal editors, authors, reviewers, funders, ethical boards or others) or the research stage at which they are performed (design, conducting, reporting or peer review). Descriptive statistical analysis will be performed. Ethics and dissemination A paper summarising the findings from this review will be published in a peer reviewed journal. This scoping review will contribute to a better understanding and a broader perspective on how the problem of adhering better to reporting guidelines has been tackled so far. This could be a major first step towards developing future strategies to improve compliance with reporting guidelines in health research

    Quantitative susceptibility mapping (QSM) and R2* of silent cerebral infarcts in sickle cell anemia

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    Silent cerebral infarction (SCI) is the most commonly reported radiological abnormality in patients with sickle cell anemia (SCA) and is associated with future clinical stroke risk. To date, there have been few histological and quantitative MRI studies of SCI and multiple radiological definitions exist. As a result, the tissue characteristics and composition of SCI remain elusive. The objective of this work was therefore to investigate the composition of segmented SCI lesions using quantitative MRI for R 2 * and quantitative magnetic susceptibility mapping (QSM). 211 SCI lesions were segmented from 32 participants with SCA and 6 controls. SCI were segmented according to two definitions (FLAIR+/-T1w-based threshold) using a semi-automated pipeline. Magnetic susceptibility (χ) and R 2 * maps were calculated from a multi-echo gradient echo sequence and mean SCI values were compared to an equivalent region of interest in normal appearing white matter (NAWM). SCI χ and R 2 * were investigated as a function of SCI definition, patient demographics, anatomical location, and cognition. Compared to NAWM, SCI were significantly less diamagnetic (χ = -0.0067 ppm vs. -0.0153 ppm, p < 0.001) and had significantly lower R 2 * (16.7 s-1 vs. 19.2 s-1, p < 0.001). SCI definition had a significant effect on the mean SCI χ and R 2 * , with lesions becoming significantly less diamagnetic and having significantly lower R 2 * after the application of a more stringent T1w-based threshold. SCI-NAWM R 2 * decrease was significantly greater in patients with SCA compared with controls (-2.84 s-1 vs. -0.64 s-1, p < 0.0001). No significant association was observed between mean SCI-NAWM χ or R2* differences and subject age, lesion anatomical location, or cognition. The increased χ and decreased R 2 * in SCI relative to NAWM observed in both patients and controls is indicative of lower myelin or increased water content within the segmented lesions. The significant SCI-NAWM R 2 * differences observed between SCI in patients with SCA and controls suggests there may be differences in tissue composition relative to NAWM in SCI in the two populations. Quantitative MRI techniques such as QSM and R 2 * mapping can be used to enhance our understanding of the pathophysiology and composition of SCI in patients with SCA as well as controls

    A survey exploring biomedical editors’ perceptions of editorial interventions to improve adherence to reporting guidelines

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    Background: Improving the completeness of reporting of biomedical research is essential for improving its usability. For this reason, hundreds of reporting guidelines have been created in the last few decades but adherence to these remains suboptimal. This survey aims to inform future evaluations of interventions to improve adherence to reporting guidelines. In particular, it gathers editors’ perceptions of a range of interventions at various stages in the editorial process. Methods: We surveyed biomedical journal editors that were knowledgeable about this topic. The questionnaire included open and closed questions that explored (i) the current practice of their journals, (ii) their perceptions of the ease of implementation and the potential effectiveness of different interventions, (iii) the barriers and facilitators associated with these interventions, and (iv) suggestions for future interventions and incentives. Results: Of the 99 editors invited, 24 (24%) completed the survey. Involving trained editors or administrative staff was deemed the potentially most effective intervention but, at the same time, it was considered moderately difficult to implement due to logistic and resource issues. Participants believed that checking adherence to guidelines goes beyond the role of peer reviewers and could decrease the overall quality of reviews. Journals incentivising adherence, and publishers and medical institutions encouraging journals to adopt strategies to boost adherence were two recurrent themesPostprint (author's final draft

    Interventions for improving the design and conduct of scientific research: A scoping review protocol [version 2; peer review: 2 approved]

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    Background Research waste is prevalent in many scientific fields despite a number of initiatives to improve research practices. Interventions to improve practice are often implemented without evaluating their effectiveness. It is therefore important to identify the interventions that have been evaluated, assess how they have been evaluated and to identify areas where further research is required. Objectives A scoping review will be undertaken to assess what interventions, aimed at researchers or research teams, to improve research design and conduct have been evaluated. This review will also consider when in the research pathway these interventions are implemented; what aspects of research design or conduct are being targeted; and who is implementing these interventions. Methods Interventions which aim to improve the design or conduct of research will be eligible for inclusion. The review will not include interventions aimed at hypothetical research projects or interventions implemented without evaluation. The following sources will be searched: MEDLINE, EMBASE, ERIC, HMIC, EconLit, Social Policy and Practice, ProQuest theses, and MetaArXiv. Hand searching of references and citations of included studies will also be undertaken. Searches will be limited to articles published in the last 10 years. Data extraction will be completed using a data extraction template developed for this review.  Results will be tabulated by type of intervention, research stage, and outcome. A narrative review will also be provided addressing each of the objectives

    Core Outcome Set-STAndards for Development: The COS-STAD recommendations

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    Background The use of core outcome sets (COS) ensures that researchers measure and report those outcomes that are most likely to be relevant to users of their research. Several hundred COS projects have been systematically identified to date, but there has been no formal quality assessment of these studies. The Core Outcome Set-STAndards for Development (COS-STAD) project aimed to identify minimum standards for the design of a COS study agreed upon by an international group, while other specific guidance exists for the final reporting of COS development studies (Core Outcome Set-STAndards for Reporting [COS-STAR]). Methods and findings An international group of experienced COS developers, methodologists, journal editors, potential users of COS (clinical trialists, systematic reviewers, and clinical guideline developers), and patient representatives produced the COS-STAD recommendations to help improve the quality of COS development and support the assessment of whether a COS had been developed using a reasonable approach. An open survey of experts generated an initial list of items, which was refined by a 2-round Delphi survey involving nearly 250 participants representing key stakeholder groups. Participants assigned importance ratings for each item using a 1–9 scale. Consensus that an item should be included in the set of minimum standards was defined as at least 70% of the voting participants from each stakeholder group providing a score between 7 and 9. The Delphi survey was followed by a consensus discussion with the study management group representing multiple stakeholder groups. COS-STAD contains 11 minimum standards that are the minimum design recommendations for all COS development projects. The recommendations focus on 3 key domains: the scope, the stakeholders, and the consensus process. Conclusions The COS-STAD project has established 11 minimum standards to be followed by COS developers when planning their projects and by users when deciding whether a COS has been developed using reasonable methods
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