23 research outputs found

    Publication Bias in Meta-Analysis: Confidence Intervals for Rosenthal's Fail-Safe Number

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    The purpose of the present paper is to assess the efficacy of confidence intervals for Rosenthal's fail-safe number. Although Rosenthal's estimator is highly used by researchers, its statistical properties are largely unexplored. First of all, we developed statistical theory which allowed us to produce confidence intervals for Rosenthal's fail-safe number.This was produced by discerning whether the number of studies analysed in a meta-analysis is fixed or random. Each case produces different variance estimators. For a given number of studies and a given distribution, we provided five variance estimators. Confidence intervals are examined with a normal approximation and a nonparametric bootstrap. The accuracy of the different confidence interval estimates was then tested by methods of simulation under different distributional assumptions. The half normal distribution variance estimator has the best probability coverage. Finally, we provide a table of lower confidence intervals for Rosenthal's estimator.Comment: Published in the International Scholarly Research Notices in December 201

    Psychometrics of health-related quality of life questionnaires in bronchiectasis:A systematic review and meta-analysis

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    INTRODUCTION: Understanding the psychometric properties of health related quality of life (HRQoL) questionnaires can help inform selection in clinical trials. OBJECTIVE: To assess the psychometric properties of HRQoL questionnaires in bronchiectasis. METHODS: A literature search was conducted. HRQoL questionnaires were assessed for psychometric properties (reliability, validity, minimal clinically important difference (MCID), floor/ceiling effects). Meta-analyses assessed the associations of HRQoL with clinical measures and responsiveness of HRQoL in clinical trials. RESULTS: 166 studies and 12 HRQoL questionnaires were included. The BHQ, LCQ, CAT and SF-36 had good internal consistency in all domains reported (Cronbach's α≥0.7) across all studies and the QoL-B, SGRQ, CRDQ and SOLQ had good internal consistency in all domains in the majority of (but not all) studies. The BHQ, SGRQ, LCQ and CAT had good test-retest reliability in all domains reported ((intraclass correlation coefficient) ICC ≥0.7) across all studies and the QoL-B, CRDQ and SOLQ had good test-retest reliability in all domains in the majority of (but not all) studies. HRQoL questionnaires were able to discriminate between demographics, important markers of clinical status, disease severity, exacerbations and bacteriology. For HRQoL responsiveness, there was a difference between the treatment and placebo effect. CONCLUSION: SGRQ was the most widely used HRQoL questionnaire in bronchiectasis studies and it had good psychometric properties, however good psychometric data are growing on bronchiectasis specific HRQoL questionnaires, QoL-B and BHQ. Future studies should focus on the medium-long term test-retest reliability, responsiveness and MCID in these HRQoL questionnaires which show potential in bronchiectasis

    Two-year real-world outcome data from a single tertiary centre shows reduced ustekinumab persistence in a non-bio-naïve Crohn's disease cohort with penetrating disease, -ostomies and sarcopenia

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    BACKGROUND: Ustekinumab was approved in 2016 for the treatment of moderate-severe Crohn's disease (CD). Clinical trials and real-world studies have suggested ustekinumab to be a safe and effective treatment; however, studies to date infrequently use imaging techniques to predict response to biologics in CD. OBJECTIVES: We assessed the 2-year real-world effectiveness and safety of ustekinumab in a tertiary CD cohort with the use of novel imaging techniques. DESIGN: Retrospective cohort study. METHODS: Retrospective data were collected between 2016 and 2021. Study end points included ustekinumab persistence, biological and/or clinical response and remission at 12, 18 and 24 months. Statistical analysis included demographic and inferential analyses. RESULTS: In all, 131 CD patients [57.3% female, median age of 26.0 (21.0-37.0)] were included. Patients were non-bio naïve, and the majority received ustekinumab as third- or fourth-line treatment. At 24 months, 61.0% (80/131) persisted with ustekinumab [52.7% (69/131) steroid free]. Clinical response was reported in 55.2% (37/67), clinical remission in 85.7% (57/67), biological response in 46.8% (22/47) and biological remission in 31.9% (15/47) of patients at 24 months. The low outcome numbers were attributable to missing data. Improvements in routine disease markers, including C-reactive protein and Harvey-Bradshaw Index, were also reflected in magnetic resonance imaging-derived disease scores. The presence of penetrating CD, an -ostomy and sarcopenia were all predictors of poorer ustekinumab outcomes (p < 0.05). CONCLUSION: Ustekinumab is effective in non-bio-naïve CD patients with non-stricturing, non-penetrating disease with an unremarkable safety profile but may be less effective in those with penetrating disease, -ostomies and sarcopenia

    Reflective Practice in Healthcare Education: An Umbrella Review

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    Reflection in healthcare education is an emerging topic with many recently published studies and reviews. This current systematic review of reviews (umbrella review) of this field explores the following aspects: which definitions and models are currently in use; how reflection impacts design, evaluation, and assessment; and what future challenges must be addressed. Nineteen reviews satisfying the inclusion criteria were identified. Emerging themes include the following: reflection is currently regarded as self-reflection and critical reflection, and the epistemology-of-practice notion is less in tandem with the evidence-based medicine paradigm of modern science than expected. Reflective techniques that are recognised in multiple settings (e.g., summative, formative, group vs. individual) have been associated with learning, but assessment as a research topic, is associated with issues of validity, reliability, and reproducibility. Future challenges include the epistemology of reflection in healthcare education and the development of approaches for practising and assessing reflection without loss of theoretical background

    A systematic review and meta-analysis of probiotics for the management of radiation induced bowel disease

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    A meta-analysis to estimate the efficacy of probiotics in prevention of radiation-induced bowel disease after pelvic radiotherapy has been performed. Previous attempts have arguably failed to provide a comprehensive analysis of clinical trials and their outcomes

    EU Development Aid towards Sub-Saharan Africa: Exploring the Normative Principle

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    The EU and most aid donors invoke a strong normative power face by explicitly connecting foreign aid with human and social development. However, how well the EU’s rhetoric is consistent with its practices as a multilateral development actor has not been explored extensively. In this study, we challenge the normative dimension of the EU’s development policy and explore whether the EU’s Official Development Assistance to Sub-Saharan Africa is based on objective deprivation on the part of recipient countries or whether it is “interest driven”. We use a least squares dummy variable model regression to examine aid flows from the EU to all 48 Sub-Saharan African states for the period 2000 to 2010. The evidence found indicates that in certain instances, aid allocation contradicts the normative rhetoric that the EU uses to describe its development policy, as the donor’s own interests in the region seem to supersede priority given to the needs of the aid recipient states. A limitation to the findings is the fact that normative values and strategic interests are not mutually exclusive. Nevertheless, the present study suggests that the EU’s portrayal as a force for good in international relations requires cautious critique

    What about clonidine for diarrhoea? A systematic review and meta-analysis of its effect in humans

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    Background: Clonidine is considered an alternative treatment for refractory diarrhoea. The evidence in the literature is scarce and not conclusive. The present paper’s purpose is to gather available evidence and provide a systematic answer regarding the effectiveness of clonidine for diarrhoea. Method: We performed a systematic review of clonidine and its effect on diarrhoea. Meta-analysis was performed with a random effects model of the standardized mean difference (SMD) or the weighted mean difference and heterogeneity was quantified with I 2 and publication bias was assessed with Egger’s and Begg’s test. Subgroup analyses and meta-regression were performed to investigate sources of heterogeneity. Any empirical study describing use of clonidine for diarrhoea in humans independent of age was included. For the meta-analysis, papers had to provide sufficient data to produce an effect measure, while case reports were not included in the meta-analysis and are discussed narratively only. Results: A total of 24 trials and seven case reports were identified. Clonidine (median dose 300 μg/day) has been used for treatment of diarrhoea in irritable bowel syndrome, faecal incontinence, diabetes, withdrawal-associated diarrhoea, intestinal failure, neuroendocrine tumours and cholera; studies were also performed on healthy volunteers. Results indicate a strong effect of clonidine on diarrhoea (SMD = −1.02, 95% confidence interval [CI] −1.46 to −0.58) with a decrease of stool volume by 0.97 l/day, stool frequency by 0.4 times/day and increase in transit time by 31 minutes. In a sensitivity analysis of studies with functional diarrhoea and sample size over 10 subjects, the effect was similar −0.99 (95% CI −1.54 to −0.43). There is however significant heterogeneity and publication bias. Heterogeneity decreased in subgroup analyses by condition but not with other factors examined. A limitation of the present study includes small study effects. Conclusion: Clonidine is effective for treatment of diarrhoea and should be considered as an alternative when all other medications have failed
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