183 research outputs found

    Evolution of treatment targets in Crohn’s disease

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    Crohn’s disease is a chronic relapsing and remitting inflammatory disorder of the gastrointestinal tract, associated with significantly morbidity due to both symptoms and complications that have a considerable detrimental impact on a patient’s quality of life. An early treat to target approach with disease modifying agents has been shown to significantly improve long term outcomes, demonstrated by a number of therapeutic targets in a number of modalities. This review will outline the current treatment targets and measures of disease burden in Crohn’s disease

    Informative cluster size in cluster-randomised trials: A case study from the TRIGGER trial

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    Background Recent work has shown that cluster-randomised trials can estimate two distinct estimands: the participant-average and cluster-average treatment effects. These can differ when participant outcomes or the treatment effect depends on the cluster size (termed informative cluster size). In this case, estimators that target one estimand (such as the analysis of unweighted cluster-level summaries, which targets the cluster-average effect) may be biased for the other. Furthermore, commonly used estimators such as mixed-effects models or generalised estimating equations with an exchangeable correlation structure can be biased for both estimands. However, there has been little empirical research into whether informative cluster size is likely to occur in practice. Method We re-analysed a cluster-randomised trial comparing two different thresholds for red blood cell transfusion in patients with acute upper gastrointestinal bleeding to explore whether estimates for the participant- and cluster-average effects differed, to provide empirical evidence for whether informative cluster size may be present. For each outcome, we first estimated a participant-average effect using independence estimating equations, which are unbiased under informative cluster size. We then compared this to two further methods: (1) a cluster-average effect estimated using either weighted independence estimating equations or unweighted cluster-level summaries, and (2) estimates from a mixed-effects model or generalised estimating equations with an exchangeable correlation structure. We then performed a small simulation study to evaluate whether observed differences between cluster- and participant-average estimates were likely to occur even if no informative cluster size was present. Results For most outcomes, treatment effect estimates from different methods were similar. However, differences of >10% occurred between participant- and cluster-average estimates for 5 of 17 outcomes (29%). We also observed several notable differences between estimates from mixed-effects models or generalised estimating equations with an exchangeable correlation structure and those based on independence estimating equations. For example, for the EQ-5D VAS score, the independence estimating equation estimate of the participant-average difference was 4.15 (95% confidence interval: −3.37 to 11.66), compared with 2.84 (95% confidence interval: −7.37 to 13.04) for the cluster-average independence estimating equation estimate, and 3.23 (95% confidence interval: −6.70 to 13.16) from a mixed-effects model. Similarly, for thromboembolic/ischaemic events, the independence estimating equation estimate for the participant-average odds ratio was 0.43 (95% confidence interval: 0.07 to 2.48), compared with 0.33 (95% confidence interval: 0.06 to 1.77) from the cluster-average estimator. Conclusion In this re-analysis, we found that estimates from the various approaches could differ, which may be due to the presence of informative cluster size. Careful consideration of the estimand and the plausibility of assumptions underpinning each estimator can help ensure an appropriate analysis methods are used. Independence estimating equations and the analysis of cluster-level summaries (with appropriate weighting for each to correspond to either the participant-average or cluster-average treatment effect) are a desirable choice when informative cluster size is deemed possible, due to their unbiasedness in this setting

    Is it time to include older adults in inflammatory bowel disease trials? A call for action

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    peer reviewedThe therapeutic management of older patients with inflammatory bowel disease (IBD) is challenging, particularly because of the absence of evidence-based guidelines for these patients, who seem to frequently be excluded from clinical trials. In this systematic review we investigated the exclusion of older patients with IBD from phase 3 studies registered on PubMed and ClinicalTrials.gov, by assessing the upper limit of age exclusion criteria and the percentage of patients older than 65 years included in the trials. Exclusion criteria other than age were also recorded, and comorbidities were analysed separately. Our review of 222 phase 3 studies shows that older patients are frequently excluded from IBD clinical trials because of their age, which was used as an exclusion criterion in 129 (58%) of the 222 assessed trials. Of the 32 trials that detailed the percentage of included patients who were 65 years or older, only 763 (5·4%) patients of the 14 124 patients included were older than 65 years. In addition to age, patients were also excluded because of comorbidities (mainly renal, hepatic, and cardiovascular, and used as an exclusion criterion in 76% of trials), a history of dysplasia (45% of trials), and previous treatment for IBD (19% of trials). We propose a three-step process that should enable the inclusion of all older patients in IBD clinical trials, regardless of their age, comorbidities, and frailty

    Reporting of randomized factorial trials was frequently inadequate.

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    OBJECTIVES: Factorial designs can allow efficient evaluation of multiple treatments within a single trial. We evaluated the design, analysis, and reporting in a sample of factorial trials. STUDY DESIGN AND SETTING: Review of 2 × 2 factorial trials evaluating health-related interventions and outcomes in humans. Using Medline, we identified articles published between January 2015 and March 2018. We randomly selected 100 articles for inclusion. RESULTS: Most trials (78%) did not provide a rationale for using a factorial design. Only 63 trials (63%) assessed the interaction for the primary outcome, and 39/63 (62%) made a further assessment for at least one secondary outcome. 12/63 trials (19%) identified a significant interaction for the primary outcome and 16/39 trials (41%) for at least one secondary outcome. Inappropriate methods of analysis to protect against potential negative effects from interactions were common, with 18 trials (18%) choosing the analysis method based on a preliminary test for interaction, and 13% (n = 10/75) of those conducting a factorial analysis including an interaction term in the model. CONCLUSION: Reporting of factorial trials was often suboptimal, and assessment of interactions was poor. Investigators often used inappropriate methods of analysis to try to protect against adverse effects of interactions

    HALT-IT - tranexamic acid for the treatment of gastrointestinal bleeding: study protocol for a randomised controlled trial

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    Documentation associated with the HALT-IT trial, a pragmatic, randomised, double-blind, placebo-controlled trial which will determine the effect of tranexamic acid on mortality, morbidity (re-bleeding, non-fatal vascular events), blood transfusion, surgical intervention, and health status in patients with acute gastrointestinal bleeding

    Systematic Review of Outcome Measures Used in Observational Studies of Adults with Eosinophilic Esophagitis.

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    BACKGROUND Over the last 20 years, diverse outcome measures have been used to evaluate the effectiveness of therapies for eosinophilic esophagitis (EoE). This systematic review aims to identify the readouts used in observational studies of topical corticosteroids, diet, and dilation in adult EoE patients. METHODS We searched MEDLINE and Embase for prospective and retrospective studies (cohorts/case series, randomized open-label, and case-control) evaluating the use of diets, dilation, and topical corticosteroids in adults with EoE. Two authors independently assessed the articles and extracted information about histologic, endoscopic, and patient-reported outcomes and tools used to assess treatment effects. RESULTS We included 69 studies that met inclusion criteria. EoE-associated endoscopic findings (assessed either as absence/presence or using Endoscopic Reference Score) were evaluated in 24/35, 11/17, and 9/17 studies of topical corticosteroids, diet, and dilation, respectively. Esophageal eosinophil density was recorded in 32/35, 17/17, and 11/17 studies of topical corticosteroids, diet, and dilation, respectively. Patient-reported outcomes were not uniformly used (only in 14, 8, and 3 studies of topical corticosteroids, diet, and dilation, respectively), and most tools were not validated for use in adults with EoE. CONCLUSIONS Despite the lack of an agreed set of core outcomes that should be recorded and reported in studies in adult EoE patients, endoscopic EoE-associated findings and esophageal eosinophil density are commonly used to assess disease activity in observational studies. Standardization of outcomes and data supporting the use of outcomes are needed to facilitate interpretation of evidence, its synthesis, and comparisons of interventions in meta-analyses of therapeutic trials in adults with EoE

    Reducing bias in open-label trials where blinded outcome assessment is not feasible: strategies from two randomised trials

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    Abstract Background: Blinded outcome assessment is recommended in open-label trials to reduce bias, however it is not always feasible. It is therefore important to find other means of reducing bias in these scenarios. Methods: We describe two randomised trials where blinded outcome assessment was not possible, and discuss the strategies used to reduce the possibility of bias. Results: TRIGGER was an open-label cluster randomised trial whose primary outcome was further bleeding. Because of the cluster randomisation, all researchers in a hospital were aware of treatment allocation and so could not perform a blinded assessment. A blinded adjudication committee was also not feasible as it was impossible to compile relevant information to send to the committee in a blinded manner. Therefore, the definition of further bleeding was modified to exclude subjective aspects (such as whether symptoms like vomiting blood were severe enough to indicate the outcome had been met), leaving only objective aspects (the presence versus absence of active bleeding in the upper gastrointestinal tract confirmed by an internal examination). TAPPS was an open-label trial whose primary outcome was whether the patient was referred for a pleural drainage procedure. Allowing a blinded assessor to decide whether to refer the patient for a procedure was not feasible as many clinicians may be reluctant to enrol patients into the trial if they cannot be involved in their care during follow-up. Assessment by an adjudication committee was not possible, as the outcome either occurred or did not. Therefore, the decision pathway for procedure referral was modified. If a chest x-ray indicated that more than a third of the pleural space filled with fluid, the patient could be referred for a procedure; otherwise, the unblinded clinician was required to reach a consensus on referral with a blinded assessor. This process allowed the unblinded clinician to be involved in the patient's care, while reducing the potential for bias. Conclusions: When blinded outcome assessment is not possible, it may be useful to modify the outcome definition or method of assessment to reduce the risk of bias

    Stakeholder views regarding ethical issues in the design and conduct of pragmatic trials : study protocol

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    This work is supported by the Canadian Institutes of Health Research through the Project Grant competition (competitive, peer reviewed), award number PJT-153045. Jeremy Grimshaw holds a Canada Research Chair in Health Knowledge Transfer and Uptake and a CIHR Foundation Grant (FDN-143269). Charles Weijer holds a Canada Research Chair in Bioethics. Joanne McKenzie is supported by an Australian National Health and Medical Research Council Career Development Fellowship (1143429). Vipul Jairath hold a personal Endowed Chair at Western University (John and Susan McDonald Endowed Chair). Marion Campbell is based with the Health Services Research Unit which is core-funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. Ian Graham is a CIHR Foundation Grant recipient (FDN# 143237).Peer reviewedPublisher PD
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