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Simera I.,Center for Statistics in Medicine
Journal of the Pakistan Medical Association | Year: 2013

Substantial evidence demonstrates widespread shortcomings in the reporting of health research publications. Reporting guidelines represent an effective tool to help improve the completeness and transparency of published papers that are much needed for their future use. Examples of key reporting guidelines (CONSORT, STROBE, COREQ, ENTREQ, PRISMA, STARD, and SQUIRE) are introduced here together with other resources supporting the writing of high quality research publications that are provided by the EQUATOR Network (www.equator-network.org). Source


Dechartres A.,French Institute of Health and Medical Research | Dechartres A.,Center dEpidemiologie Clinique | Dechartres A.,University of Paris Descartes | Altman D.G.,Center for Statistics in Medicine | And 11 more authors.
JAMA - Journal of the American Medical Association | Year: 2014

IMPORTANCE: A persistent dilemma when performing meta-analyses is whether all available trials should be included in the meta-analysis. OBJECTIVES: To compare treatment outcomes estimated by meta-analysis of all trials and several alternative analytic strategies: single most precise trial (ie, trial with the narrowest confidence interval), meta-analysis restricted to the 25% largest trials, limit meta-analysis (a meta-analysis model adjusted for small-study effect), and meta-analysis restricted to trials at low overall risk of bias. DATA SOURCES: One hundred sixty-three meta-analyses published between 2008 and 2010 in high-impact-factor journals and between 2011 and 2013 in the Cochrane Database of Systematic Reviews: 92 (705 randomized clinical trials [RCTs]) with subjective outcomes and 71 (535 RCTs) with objective outcomes. DATA SYNTHESIS: For each meta-analysis, the difference in treatment outcomes between meta-analysis of all trials and each alternative strategy, expressed as a ratio of odds ratios (ROR), was assessed considering the dependency between strategies. A difference greater than 30% was considered substantial. RORs were combined by random-effects meta-analysis models to obtain an average difference across the sample. An ROR greater than 1 indicates larger treatment outcomes with meta-analysis of all trials. Subjective and objective outcomes were analyzed separately. RESULTS: Treatment outcomes were larger in the meta-analysis of all trials than in the single most precise trial (combined ROR, 1.13 [95%CI, 1.07-1.19]) for subjective outcomes and 1.03 (95%CI, 1.01-1.05) for objective outcomes). The difference in treatment outcomes between these strategies was substantial in 47 of 92 (51%) meta-analyses of subjective outcomes (meta-analysis of all trials showing larger outcomes in 40/47) and in 28 of 71 (39%) meta-analyses of objective outcomes (meta-analysis of all trials showing larger outcomes in 21/28). The combined ROR for subjective and objective outcomes was, respectively, 1.08 (95%CI, 1.04-1.13) and 1.03 (95%CI, 1.00-1.06) when comparing meta-analysis of all trials and meta-analysis of the 25% largest trials, 1.17 (95%CI, 1.11-1.22) and 1.13 (95%CI, 0.82-1.55) when comparing meta-analysis of all trials and limit meta-analysis, and 0.94 (95%CI, 0.86-1.04) and 1.03 (95%CI, 1.00-1.06) when comparing meta-analysis of all trials and meta-analysis restricted to trials at low risk of bias. CONCLUSIONS AND RELEVANCE: Estimation of treatment outcomes in meta-analyses differs depending on the strategy used. This instability in findings can result in major alterations in the conclusions derived from the analysis and underlines the need for systematic sensitivity analyses. Source


von Elm E.,University of Lausanne | Altman D.G.,Center for Statistics in Medicine | Egger M.,University of Bern | Egger M.,University of Cape Town | And 3 more authors.
International Journal of Surgery | Year: 2014

Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies. © 2014 The Authors. Source


Molyneux A.J.,University of Oxford | Birks J.,Center for Statistics in Medicine | Clarke A.,University of Oxford | Sneade M.,University of Oxford | Kerr R.S.C.,John Radcliffe Hospital
The Lancet | Year: 2015

Background Previous analyses of the International Subarachnoid Aneurysm Trial (ISAT) cohort have reported on the risks of recurrent subarachnoid haemorrhage and death or dependency for a minimum of 5 years and up to a maximum of 14 years after treatment of a ruptured intracranial aneurysm with either neurosurgical clipping or endovascular coiling. At 1 year there was a 7% absolute and a 24% relative risk reduction of death and dependency in the coiling group compared with the clipping group, but the medium-term results showed the increased need for re-treatment of the target aneurysm in the patients given coiling. We report the long-term follow-up of patients in this UK cohort. Methods In ISAT, patients were randomly allocated to either neurosurgical clipping or endovascular coiling after a subarachnoid haemorrhage, assuming treatment equipoise, between Sept 12, 1994, and May 1, 2002. We followed up 1644 patients in 22 UK neurosurgical centres for death and clinical outcomes for 10·0-18·5 years. We assessed dependency as self-reported modified Rankin scale score obtained through yearly questionnaires. Data for recurrent aneurysms and rebleeding events were collected from questionnaires and from hospital and general practitioner records. The Office for National Statistics supplied data on deaths. This study is registered, number ISRCTN49866681. Findings At 10 years, 674 (83%) of 809 patients allocated endovascular coiling and 657 (79%) of 835 patients allocated neurosurgical clipping were alive (odds ratio [OR] 1·35, 95% CI 1·06-1·73). Of 1003 individuals who returned a questionnaire at 10 years, 435 (82%) patients treated with endovascular coiling and 370 (78%) patients treated with neurosurgical clipping were independent (modified Rankin scale score 0-2; OR 1·25; 95% CI 0·92-1·71). Patients in the endovascular treatment group were more likely to be alive and independent at 10 years than were patients in the neurosurgery group (OR 1·34, 95% CI 1·07-1·67). 33 patients had a recurrent subarachnoid haemorrhage more than 1 year after their initial haemorrhage (17 from the target aneurysm). Interpretation Although rates of increased dependency alone did not differ between groups, the probability of death or dependency was significantly greater in the neurosurgical group than in the endovascular group. Rebleeding was more likely after endovascular coiling than after neurosurgical clipping, but the risk was small and the probability of disability-free survival was significantly greater in the endovascular group than in the neurosurgical group at 10 years. Funding UK Medical Research Council. © 2015 Elsevier Ltd. Source


Holloway C.J.,Anatomy and Genetics | Holloway C.J.,University of Oxford | Ntusi N.,University of Oxford | Suttie J.,University of Oxford | And 12 more authors.
Circulation | Year: 2013

BACKGROUND - : HIV infection continues to be endemic worldwide. Although treatments are successful, it remains controversial whether patients receiving optimal therapy have structural, functional, or biochemical cardiac abnormalities that may underlie their increased cardiac morbidity and mortality. The purpose of this study was to characterize myocardial abnormalities in a contemporary group of HIV-infected individuals undergoing combination antiretroviral therapy. METHODS AND RESULTS - : Volunteers with HIV who were undergoing combination antiretroviral therapy and age-matched control subjects without a history of cardiovascular disease underwent cardiac magnetic resonance imaging and spectroscopy for the determination of cardiac function, myocardial fibrosis, and myocardial lipid content. A total of 129 participants were included in this analysis. Compared with age-matched control subjects (n=39; 30.23%), HIV-infected subjects undergoing combination antiretroviral therapy (n=90; 69.77%) had 47% higher median myocardial lipid levels (P <0.003) and 74% higher median plasma triglyceride levels (both P<0.001). Myocardial fibrosis, predominantly in the basal inferolateral wall of the left ventricle, was observed in 76% of HIV-infected subjects compared with 13% of control subjects (P<0.001). Peak myocardial systolic and diastolic longitudinal strain were also lower in HIV-infected individuals than in control subjects and remained statistically significant after adjustment for available confounders. CONCLUSIONS - : Comprehensive cardiac imaging revealed cardiac steatosis, alterations in cardiac function, and a high prevalence of myocardial fibrosis in a contemporary group of asymptomatic HIV-infected subjects undergoing combination antiretroviral therapy. Cardiac steatosis and fibrosis may underlie cardiac dysfunction and increased cardiovascular morbidity and mortality in subjects with HIV. © 2013 American Heart Association, Inc. Source

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