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.

Green tea for weight loss and weight maintenance in overweight or obese adults

Abstract: Background Preparations of green tea are used as aids in weight loss and weight maintenance. Catechins and caffeine, both contained in green tea, are each believed to have a role in increasing energy metabolism, which may lead to weight loss. A number of randomised controlled trials (RCTs) evaluating the role of green tea in weight loss have been published; however, the efficacy of green tea preparations in weight loss remains unclear. Objectives To assess the efficacy and safety of green tea preparations for weight loss and weight maintenance in overweight or obese adults. Search methods We searched the following databases from inception to specified date as well as reference lists of relevant articles: The Cochrane Library (Issue 12, 2011), MEDLINE (December 2011), EMBASE (December 2011), CINAHL (January 2012), AMED (January 2012), Biological Abstracts (January 2012), IBIDS (August 2010), Obesity+ (January 2012), IPA (January 2012) and Web of Science (December 2011). Current Controlled Trials with links to other databases of ongoing trials was also searched. Selection criteria RCTs of at least 12 weeks' duration comparing green tea preparations to a control in overweight or obese adults. Data collection and analysis Three authors independently extracted data, assessed studies for risk of bias and quality, with differences resolved by consensus. Heterogeneity of included studies was assessed visually using forest plots and quantified using the I2 statistic. We synthesised data using meta-analysis and descriptive analysis as appropriate; subgroup and sensitivity analyses were conducted. Adverse effects reported in studies were recorded. Main results Due to the level of heterogeneity among studies, studies were divided into two groups; those conducted in Japan and those conducted outside Japan. Study length ranged between 12 and 13 weeks. Meta-analysis of six studies conducted outside Japan showed a mean difference (MD) in weight loss of -0.04 kg (95% CI -0.5 to 0.4; P = 0.88; I2 = 18%; 532 participants). The eight studies conducted in Japan were not similar enough to allow pooling of results and MD in weight loss ranged from -0.2 kg to -3.5 kg (1030 participants) in favour of green tea preparations. Meta-analysis of studies measuring change in body mass index (BMI) conducted outside Japan showed a MD in BMI of -0.2 kg/m2 (95% CI -0.5 to 0.1; P = 0.21; I2 = 38%; 222 participants). Differences among the eight studies conducted in Japan did not allow pooling of results and showed a reduction in BMI ranging from no effect to -1.3 kg/m2 (1030 participants), in favour of green tea preparations over control. Meta-analysis of five studies conducted outside Japan and measuring waist circumference reported a MD of -0.2 cm (95% CI -1.4 to 0.9; P = 0.70; I2 = 58%; 404 participants). Differences among the eight studies conducted in Japan did not allow pooling of results and showed effects on waist circumference ranging from a gain of 1 cm to a loss of 3.3 cm (1030 participants). Meta-analysis for three weight loss studies, conducted outside Japan, with waist-to-hip ratio data (144 participants) yielded no significant change (MD 0; 95% CI -0.02 to 0.01). Analysis of two studies conducted to determine if green tea could help to maintain weight after a period of weight loss (184 participants) showed a change in weight loss of 0.6 to -1.6 kg, a change in BMI from 0.2 to -0.5 kg/m2 and a change in waist circumference from 0.3 to -1.7 cm. In the eight studies that recorded adverse events, four reported adverse events that were mild to moderate, with the exception of two (green tea preparations group) that required hospitalisation (reported as not associated with the intervention). Nine studies reported on compliance/adherence, one study assessed attitude towards eating as part of the health-related quality of life outcome. No studies reported on patient satisfaction, morbidity or cost. Authors' conclusions Green tea preparations appear to induce a small, statistically non-significant weight loss in overweight or obese adults. Because the amount of weight loss is small, it is not likely to be clinically important. Green tea had no significant effect on the maintenance of weight loss. Of those studies recording information on adverse events, only two identified an adverse event requiring hospitalisation. The remaining adverse events were judged to be mild to moderate.

Valerian for anxiety disorders

Abstract: Background Anxiety disorders are very common mental health problems in the general population and in primary care settings Herbal medicines are popular and used worldwide and might be considered as a treatment option for anxiety if shown to be effective and safe Objectives To investigate the effectiveness and safety of valerian for treating anxiety disorders Search methods Electronic searches: The Cochrane Collaboration Depression, Anxiety and Neurosis Cochrane Controlled Trials Register (CCDANCTR-Studies and CCDANCTR-References) searched on 04/08/2006, MEDLINE, Lilacs References of all identified studies were inspected for additional studies First authors of each included study, manufacturers of valerian products, and experts in the field were contacted for information regarding unpublished trials Selection criteria Randomised controlled trials (RCTs) and quasi-randomised trials of valerian extract of any dose, regime, or method of administration, for people with any primary diagnosis of general anxiety disorder, anxiety neurosis, chronic anxiety status, or any other disorder in which anxiety is the primary symptom (panic disorder, obsessive compulsive disorder, social phobia, agoraphobia, other types of phobia, postraumatic stress disorder) Effectiveness was measured using clinical outcome measures and other scales for anxiety symptoms Data collection and analysis Two review authors independently applied inclusion criteria, extracted and entered data, and performed the trial quality assessments Where disagreements occurred, the third review author was consulted Methodological quality of included trials was assessed using Cochrane Handbook criteria For dichotomous outcomes, relative risk (RR) was calculated, and for continuous outcomes, the weighted mean difference (WMD) was calculated, with their respective 95% confidence intervals Main results One RCT involving 36 patients with generalised anxiety disorder was eligible for inclusion This was a 4 week pilot study of valerian, diazepam and placebo There were no significant differences between the valerian and placebo groups in HAM-A total scores, or in somatic and psychic factor scores Similarly, there were no significant differences in HAM-A scores between the valerian and diazepam groups, although based on STAI-Trait scores, significantly greater symptom improvement was indicated in the diazepam group There were no significant differences between the three groups in the number of patients reporting side effects or in dropout rates Authors' conclusions Since only one small study is currently available, there is insufficient evidence to draw any conclusions about the efficacy or safety of valerian compared with placebo or diazepam for anxiety disorders RCTs involving larger samples and comparing valerian with placebo or other interventions used to treat of anxiety disorders, such as antidepressants, are needed

The ORION statement: guidelines for transparent reporting of outbreak reports and intervention studies of nosocomial infection.

Abstract: The quality of research in hospital epidemiology (infection control) must be improved to be robust enough to influence policy and practice. In order to raise the standards of research and publication, a CONSORT equivalent for these largely quasi-experimental studies has been prepared by the authors of two relevant systematic reviews, following consultation with learned societies, editors of journals and researchers. It consists of a 22 item checklist, and a summary table. The emphasis is on transparency to improve the quality of reporting and on the use of appropriate statistical techniques. The statement has been endorsed by a number of professional special interest groups and societies. Like CONSORT, ORION should be considered a 'work in progress', which requires ongoing dialogue for successful promotion and dissemination. The statement is therefore offered for further public discussion. Journals and research councils are strongly recommended to incorporate it into their submission and reviewing processes. Feedback to the authors is encouraged and the statement will be revised in 2 years.