Cochrane Collaboration

About: Cochrane Collaboration is a nonprofit organization based out in Oxford, United Kingdom. It is known for research contribution in the topics: Systematic review & Randomized controlled trial. The organization has 1995 authors who have published 3928 publications receiving 382695 citations.

A systematic review of how patients value COPD outcomes

Abstract: Our objective was to summarise systematically all research evidence related to how patients value outcomes in chronic obstructive pulmonary disease (COPD).We conducted a systematic review (systematic review registration number CRD42015015206) by searching PubMed, Embase, PsycInfo and CINAHL, and included reports that assessed the relative importance of outcomes from COPD patients' perspective. Two authors independently determined the eligibility of studies, abstracted the eligible studies and assessed risk of bias. We narratively summarised eligible studies, meta-analysed utilities for individual outcomes and assessed the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluations approach.We included 217 quantitative studies. Investigators most commonly used utility measurements of outcomes (n=136), discrete choice exercises (n=13), probability trade-off (n=4) and forced choice techniques (n=46). Patients rated adverse events as important but on average, less so than symptom relief. Exacerbation and hospitalisation due to exacerbation are the outcomes that COPD patients rate as most important. This systematic review provides a comprehensive registry of related studies.

Network meta-analysis: the highest level of medical evidence?

Abstract: Network meta-analyses synthesise networks of direct and indirect comparisons of interventions, and enable researchers to simultaneously assess the effects of more than two interventions for the same condition.1 Indirect evidence refers to estimates from different direct meta-analyses with a common comparator and allows for treatment comparisons that have not been directly compared in a clinical trial.1 Guidelines from the National Institute for Health and Care Excellence (NICE)2 and the Cochrane Collaboration3 typically prefer direct evidence from randomised clinical trials and conventional meta-analyses to indirect evidence. However, the WHO have recently begun using network meta-analyses to inform clinical guidelines,4 the global scientific production of network meta-analyses is increasing rapidly5 and some argue that the methodology should represent the highest level of evidence for instructing clinical decision-making.6 Are we witnessing a shift in what constitutes the highest level of medical evidence? As network meta-analyses are becoming more influential in informing clinicians and decision-makers, we need a thorough discussion of reporting standards and methodological concerns. A previous paper published in Evidence-Based Medicine considered several challenges related to heterogeneity and inconsistency (see box 1 for a description of inconsistency) in network meta-analyses.7 The present analysis considers five additional topics relevant to network meta-analyses: quality of evidence, statistical power, random errors, multiplicity issues and treatment rankings. Our aim is to debate methodological and reporting problems for these topics, and their relevance for evidence-based practice. A glossary of key terms used throughout the article is provided in box 1.Box 1 ### Glossary of terms (concerning network meta-analyses) #### Direct evidence Effect estimates from a head-to-head comparison (eg, randomised trial on A vs B). Conventional meta-analyses use direct comparisons from randomised trials. #### Indirect evidence Effect estimates from multiple direct comparisons that share a common comparator (eg, randomised trial on A …

Randomized controlled trials in schizophrenia: a critical perspective on the literature.

Abstract: Objective: The randomized trial provides an opportunity to minimize the inclusion of biases in the evaluation of interventions in psychiatry. Difficulties arise, however, when applying their results to `real world' clinical practice and decision-making. We, therefore, examined the real world applicability of schizophrenia trials. Method: A narrative overview of the content and quality of the randomized trials relevant to the care of those with schizophrenia is provided. Results: Complex, explanatory, under-powered randomized drug trials dominate evaluative research in schizophrenia. Conclusion: Explanatory designs are a necessary but insufficient step in establishing the true worth of interventions in schizophrenia. Research from other spheres of mental health and wider health care suggest that pragmatic trials are feasible. This design allows large scale trials to be conducted which include patients which we would recognize from routine practice and which record outcomes which are of genuine interest to decision-makers.

Replacement versus repair of defective restorations in adults: resin composite.

Abstract: BACKGROUND: Composite filling materials have been increasingly used for the restoration of posterior teeth in recent years as a tooth-coloured alternative to amalgam. As with any filling material composites have a finite life-span. Traditionally, replacement was the ideal approach to treat defective composite restorations, however, repairing composites offers an alternative more conservative approach to the tooth structure where restorations are partly still serviceable. Repairing the restoration has the potential of taking less time and may sometimes be performed without the use of local anaesthesia hence it may be less distressing for a patient when compared with replacement. OBJECTIVES: To evaluate the effects of replacing (with resin composite) versus repair (with resin composite) in the management of defective resin composite dental restorations in permanent molar and premolar teeth. SEARCH METHODS: For the identification of studies relevant to this review we searched the Cochrane Oral Health Group's Trials Register (to 24 July 2013); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 6); MEDLINE via OVID (1946 to 24 July 2013); EMBASE via OVID (1980 to 24 July 2013); BIOSIS via Web of Knowledge (1969 to 24 July 2013); Web of Science (1945 to 24 July 2013); and OpenGrey (to 24 July 2013). Researchers, experts and organisations known to be involved in this field were contacted in order to trace unpublished or ongoing studies. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Trials were selected if they met the following criteria: randomised controlled trial (including split-mouth studies), involving replacement and repair of resin composite restorations in adults with a defective molar restoration in a permanent molar or premolar teeth. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed titles and abstracts for each article identified by the searches in order to decide whether the article was likely to be relevant. Full papers were obtained for relevant articles and both review authors studied these. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis. MAIN RESULTS: The search strategy retrieved 298 potentially eligible studies, after de-duplication. After examination of the titles and abstracts, full texts of potentially relevant studies were retrieved but none of the retrieved studies met the inclusion criteria of the review. AUTHORS' CONCLUSIONS: There are no published randomised controlled trials relevant to this review question. There is therefore a need for methodologically sound randomised controlled trials that are reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement (www.consort-statement.org/). Further research also needs to explore qualitatively the views of patients on repairing versus replacement and investigate themes around pain, anxiety and distress, time and costs.

Classification systems for lower extremity amputation prediction in subjects with active diabetic foot ulcer: a systematic review and meta-analysis.

Abstract: Aim We systematically review the available systems used to classify diabetic foot ulcers in order to synthesize their methodological qualitative issues and accuracy to predict lower extremity amputation, as this may represent a critical point in these patients' care. Material and Methods Two investigators searched, in EBSCO, ISI, PubMed and SCOPUS databases, and independently selected studies published until May 2013 and reporting prognostic accuracy and/or reliability of specific systems for patients with diabetic foot ulcer in order to predict lower extremity amputation. Results We included 25 studies reporting a prevalence of lower extremity amputation between 6% and 78%. Eight different diabetic foot ulcer descriptions and seven prognostic stratification classification systems were addressed with a variable (1–9) number of factors included, specially peripheral arterial disease (n = 12) or infection at the ulcer site (n = 10) or ulcer depth (n = 10). The Meggitt–Wagner, S(AD)SAD and Texas University Classification systems were the most extensively validated, whereas ten classifications were derived or validated only once. Reliability was reported in a single study, and accuracy measures were reported in five studies with another eight allowing their calculation. Pooled accuracy ranged from 0.65 (for gangrene) to 0.74 (for infection). Conclusion There are numerous classification systems for diabetic foot ulcer outcome prediction, but only few studies evaluated their reliability or external validity. Studies rarely validated several systems simultaneously and only a few reported accuracy measures. Further studies assessing reliability and accuracy of the available systems and their composing variables are needed. Copyright © 2014 John Wiley & Sons, Ltd.