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.

Head-mounted peripheral vision display systems and methods

Abstract: A head-mounted peripheral vision display and associated methods display information to a user without distraction. A plurality of light display elements are positioned within an area of peripheral vision of at least one eye of the user such that the information is imparted to the user without a need for repositioning or refocusing of the eye. The information may be determined from data received from one or more sensors and an illumination pattern is determined based upon the performance information. The light display elements are controlled to display the illumination pattern to the user.

Drugs versus placebo for dysthymia

Abstract: OBJECTIVES: Dysthymia is a depressive disorder of chronic nature but of less severity than major depression, which depressive symptoms are more or less continuous for at least two years. The aim of this review was to conduct a systematic review of all RCTs comparing drugs and placebo for dysthymia. SEARCH STRATEGY: Electronic searches of Cochrane Library, EMBASE, MEDLINE, PsycLIT, Biological Abstracts and LILACS; reference searching; personal communication; conference abstracts; unpublished trials from the pharmaceutical industry; book chapters on the treatment of depression. SELECTION CRITERIA: The inclusion criteria for all randomised controlled trials were that they should focus on the use of drugs versus placebo for dysthymic patients. Exclusion criteria were: non randomised, mixed major depression/ dysthymia (trials not providing separate data) and depression secondary to other disorders (e.g. substance abuse). DATA COLLECTION AND ANALYSIS: The reviewers extracted the data independently. In order to achieve an intention-to-treat analysis, when trials failed to report it was assumed that people who died or dropped out had no improvement. Authors of relevant trials were contacted for additional and missing data. Absence of treatment response as defined by authors was the main measure of outcome used. Relative Risks (RR) and 95% confidence intervals (CI) of dichotomous data were calculated with the Random Effects Model. Where possible, number needed to treat (NNT) and number needed to harm (NNH) were estimated, taking the reciprocal of the absolute risk reduction. MAIN RESULTS: Currently the review includes 15 trials. Similar results were obtained in terms of efficacy for different groups of drugs, such as tricyclic (TCA), selective serotonin reuptake inhibitors (SSRI), monoamine oxidase inhibitors (MAOI) and other drugs (sulpiride, amineptine, and ritanserin). The pooled RR for absence of treatment response was 0. 68 (95% CI 0.59-0.78) for TCA and the NNT was 4.3 (95% CI 3.2-6.5). SSRIs showed similar RR for this outcome: 0.64 (95% CI 0.55-0.74), the NNT being 4.7 (95% CI 3.5-6.9). Concerning MAOIs, the RR was 0. 59 (95% CI 0.48-0.71) and the NNT was 2.9 (95% CI 2.2-4.3). Other drugs (amisulpride, amineptine and ritanserin) showed similar results in terms of absence of treatment response. Using more stringent criteria for improvement - full remission - the results were unchanged. Patients treated on TCA were more likely to report adverse events, compared with placebo. REVIEWER'S CONCLUSIONS: Drugs are effective in the treatment of dysthymia with no differences between and within class of drugs. Tricyclic antidepressants are more likely to cause adverse events and dropouts. As dysthymia is a chronic condition, there remains little information on quality of life and medium or long-term outcome.

Analysis of the systematic reviews process in reports of network meta-analyses: methodological systematic review

Abstract: Objective To examine whether network meta-analyses, increasingly used to assess comparative effectiveness of healthcare interventions, follow the key methodological recommendations for reporting and conduct of systematic reviews. Design Methodological systematic review of reports of network meta-analyses. Data sources Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Medline, and Embase, searched from inception to 12 July 2012. Review methods All network meta-analyses comparing clinical efficacy of three or more interventions based on randomised controlled trials, excluding meta-analyses with an open loop network of three interventions. We assessed the reporting of general characteristics and key methodological components of the systematic review process using two composite outcomes. For some components, if reporting was adequate, we assessed their conduct quality. Results Of 121 network meta-analyses covering a wide range of medical areas, 100 (83%) assessed pharmacological interventions and 11 (9%) non-pharmacological interventions; 56 (46%) were published in journals with a high impact factor. The electronic search strategy for each database was not reported in 88 (73%) network meta-analyses; for 36 (30%), the primary outcome was not clearly identified. Overall, 61 (50%) network meta-analyses did not report any information regarding the assessment of risk of bias of individual studies, and 103 (85%) did not report any methods to assess the likelihood of publication bias. Overall, 87 (72%) network meta-analyses did not report the literature search, searched only one database, did not search other sources, or did not report an assessment of risk of bias of individual studies. These methodological components did not differ by publication in a general or specialty journal or by public or private funding. Conclusions Essential methodological components of the systematic review process—conducting a literature search and assessing risk of bias of individual studies—are frequently lacking in reports of network meta-analyses, even when published in journals with high impact factors.