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.

Uncertainties in baseline risk estimates and confidence in treatment effects

Abstract: The GRADE system provides a framework for evaluating how risk of bias, publication bias, imprecision, inconsistency, and indirectness may reduce confidence in estimates of relative effects of interventions on outcomes. However, GRADE and all other systems for rating confidence in effect estimates do not fully address uncertainty in baseline risk and its impact on confidence in absolute estimates of treatment effect. In this article the authors examine factors that may reduce confidence in estimates of baseline risk and thus estimates of absolute treatment benefit

Ursodeoxycholic acid and/or antibiotics for prevention of biliary stent occlusion.

Abstract: BACKGROUND Malignant biliary obstruction, which requires endoscopic stenting as palliative therapy, is often complicated by clogging of the stent with subsequent jaundice and/or cholangitis. Stent clogging may be caused by microbiological adhesion and biliary stasis. Therefore, antibiotics and choleretic agents like ursodeoxycholic acid (UDCA) have been investigated to see whether they prolong stent patency. OBJECTIVES To evaluate if UDCA and/or antibiotics may prolong stent patency and survival in patients with strictures of the biliary tract and endoscopically inserted stents. SEARCH STRATEGY The Trials Register of The Cochrane Hepato-Biliary Group, The Cochrane Library, MEDLINE, Current Contents, EMBASE, and CancerLit were searched until June 2001. Reference lists of the identified articles were checked for further trials. SELECTION CRITERIA All randomised or quasi-randomised clinical trials investigating UDCA and/or antibiotics in patients with biliary stents were considered for inclusion, regardless of blinding, language, and publication status. DATA COLLECTION AND ANALYSIS Trial inclusion, quality assessment, and data extraction were performed independently by two reviewers. Principal investigators were contacted for further information. Survival data were combined by using hazard ratios (with 95% confidence interval (95% CI)). MAIN RESULTS Five non-blinded randomised trials with 258 patients with malignant strictures treated with polyethylene stents were included. Three trials, including 152 patients, investigated a combination of UDCA and antibiotics versus no treatment. The meta-analysis of these three trials does not show a significant treatment effect on the duration of stent patency (hazard ratio (random effects model) 0.58, 95% CI 0.22 to 1.54) or mortality (hazard ratio (fixed effect model) 0.99, 95% CI 0.68 to 1.43). Two trials with 106 patients compared antibiotics with no treatment, one of these trials used a combination of antibiotics and rowachol (an 'alternative' drug of the 'mint' family). The pooled results of these two trials do not show significant effects of antibiotics on the duration of stent patency (hazard ratio (fixed effect model) 0.69 (95% CI 0.37 to 1.30)) or mortality (hazard ratio (fixed effect model) 1.23 (95% CI 0.72 to 2.08). Data concerning duration of hospital stay, frequency of cholangitis, and rate of infectious complications due to selection of antibiotic resistant bacteria strains were not available. REVIEWER'S CONCLUSIONS Treatment with UDCA and/or antibiotics to prevent clogging of biliary stents in patients with malignant stricture of the biliary tract cannot be recommended routinely on the basis of the existing randomised clinical trials. Further trials are needed with rigorous methodology and sufficient statistical power.

A Systematic Review of Resistance Training Versus Endurance Training in COPD.

Abstract: Purpose Endurance training (ET) as part of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD) has been shown to improve exercise capacity and health-related quality of life, but dyspnea limits the exercise intensity. Therefore, resistance training (RT), which may cause less dyspnea, could be an alternative. The purpose of this review was to formulate evidence-based recommendations on the use of RT in pulmonary rehabilitation of patients with COPD. Our primary outcomes were health-related quality of life, activities of daily living, dyspnea, possible harm, and total mortality. Our secondary outcomes were walking distance, lean body mass, muscle strength, and exercise capacity. Methods We identified randomized controlled trials through a systematic multidatabase search. One author checked titles and abstracts for relevance using broad inclusion criteria, whereas 2 authors independently checked the full-text articles for eligibility. Two authors independently extracted data and assessed the risk of bias and quality of evidence. Meta-analyses were performed when deemed feasible based on the quality and amount of data. Results We included 8 randomized controlled trials (328 participants). On the basis of moderate- to very low-quality evidence, we found no clinically important difference between RT and ET. We did not find sufficient data for a meta-analysis of total mortality, adverse events, dyspnea, or lean body mass. Conclusions We found that in patients with COPD, RT seems to induce the same beneficial effects as ET. Therefore, we recommend that RT should be considered according to patient preferences when designing a pulmonary rehabilitation program for patients with COPD.

How useful are Cochrane reviews in identifying research needs

Abstract: Objectives: To determine the extent to which reports of Cochrane reviews recommend the need for further research and, if so, the extent to which they make suggestions regarding that research.Methods: We examined all 2535 reviews in Issue 4, 2005 of The Cochrane Library. Each review was categorized on the basis of whether a suggestion was included about specific interventions, participants, or outcome measures that should be included in future research. We also identified the frequency with which reviews conclude that no more research is needed or feasible, noted the need for further systematic reviewing, and refered to a relevant ongoing or planned study. We also report the number of studies listed in the 'Ongoing Studies' section in each review.Results: Only 3.2% of reviews suggested explicitly that no more research is needed or feasible. In 82.0% of reviews, suggestions were made as to the specific interventions that need evaluating, in 30.2% the appropriate participants were suggested, and in 51.9% out...