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.

Declaración PRISMA: una propuesta para mejorar la publicación de revisiones sistemáticas y metaanálisis

Abstract: En el ano 1999, despues de 3 anos de trabajo, se publico la declaracion QUOROM, cuyo objetivo era establecer unas normas para mejorar la calidad de la presentacion de los metaanalisis de ensayos clinicos aleatorizados. Se publico un comentario de este documento en un monografico sobre listas de comprobacion para autores, revisores y editores de revistas medicas en Medicina Clinica. En resumen, la declaracion Quality Of Reporting Of Metaanalysis (QUOROM) incluye una lista de comprobacion estructurada con 18 items que los autores de un metaanalisis, y tambien los editores de revistas, deberian considerar a la hora de publicar su trabajo en forma de articulo en una revista medica. Ademas, incluye un diagrama de flujo que describe todo el proceso, desde la identificacion inicial de los estudios potencialmente relevantes hasta la seleccion definitiva de estos. La finalidad de QUOROM era animar a los autores a que proporcionaran toda aquella informacion que resulta esencial para interpretar y utilizar adecuadamente los resultados de un metaanalisis. Numerosos estudios realizados con posterioridad a la publicacion de QUOROM han mostrado que la calidad de los metaanalisis publicados en revistas medicas todavia es deficiente. A pesar de esto, y a diferencia de otras iniciativas similares como CONSORT (dirigida a ensayos clinicos), la declaracion QUOROM no parece

The effect of English-language restriction on systematic review-based meta-analyses: a systematic review of empirical studies.

Abstract: Objectives: The English language is generally perceived to be the universal language of science. However, the exclusive reliance on English-language studies may not represent all of the evidence. Excluding languages other than English (LOE) may introduce a language bias and lead to erroneous conclusions.Study Design and Setting: We conducted a comprehensive literature search using bibliographic databases and grey literature sources. Studies were eligible for inclusion if they measured the effect of excluding randomized controlled trials (RCTs) reported in LOE from systematic review-based meta-analyses (SR/MA) for one or more outcomes.Results: None of the included studies found major differences between summary treatment effects in English-language restricted meta-analyses and LOE-inclusive meta-analyses. Findings differed about the methodological and reporting quality of trials reported in LOE. The precision of pooled estimates improved with the inclusion of LOE trials.Conclusions: Overall, we found no evidence of a systematic bias from the use of language restrictions in systematic review-based meta-analyses in conventional medicine. Further research is needed to determine the impact of language restriction on systematic reviews in particular fields of medicine.

Clinical Practice Guideline Tympanostomy Tubes in Children

Abstract: ObjectiveInsertion of tympanostomy tubes is the most common ambulatory surgery performed on children in the United States. Tympanostomy tubes are most often inserted because of persistent middle ea...

Publication bias in clinical trials due to statistical significance or direction of trial results.

Abstract: Background The tendency for authors to submit, and of journals to accept, manuscripts for publication based on the direction or strength of the study findings has been termed publication bias. Objectives To assess the extent to which publication of a cohort of clinical trials is influenced by the statistical significance, perceived importance, or direction of their results. Search methods We searched the Cochrane Methodology Register (The Cochrane Library [Online] Issue 2, 2007), MEDLINE (1950 to March Week 2 2007), EMBASE (1980 to Week 11 2007) and Ovid MEDLINE In-Process & Other Non-Indexed Citations (March 21 2007). We also searched the Science Citation Index (April 2007), checked reference lists of relevant articles and contacted researchers to identify additional studies. Selection criteria Studies containing analyses of the association between publication and the statistical significance or direction of the results (trial findings), for a cohort of registered clinical trials. Data collection and analysis Two authors independently extracted data. We classified findings as either positive (defined as results classified by the investigators as statistically significant (P < 0.05), or perceived as striking or important, or showing a positive direction of effect) or negative (findings that were not statistically significant (P ≥ 0.05), or perceived as unimportant, or showing a negative or null direction in effect). We extracted information on other potential risk factors for failure to publish, when these data were available. Main results Five studies were included. Trials with positive findings were more likely to be published than trials with negative or null findings (odds ratio 3.90; 95% confidence interval 2.68 to 5.68). This corresponds to a risk ratio of 1.78 (95% CI 1.58 to 1.95), assuming that 41% of negative trials are published (the median among the included studies, range = 11% to 85%). In absolute terms, this means that if 41% of negative trials are published, we would expect that 73% of positive trials would be published. Two studies assessed time to publication and showed that trials with positive findings tended to be published after four to five years compared to those with negative findings, which were published after six to eight years. Three studies found no statistically significant association between sample size and publication. One study found no significant association between either funding mechanism, investigator rank, or sex and publication. Authors' conclusions Trials with positive findings are published more often, and more quickly, than trials with negative findings.

Sex and Gender Equity in Research: rationale for the SAGER guidelines and recommended use

Abstract: Sex and gender differences are often overlooked in research design, study implementation and scientific reporting, as well as in general science communication. This oversight limits the generalizability of research findings and their applicability to clinical practice, in particular for women but also for men. This article describes the rationale for an international set of guidelines to encourage a more systematic approach to the reporting of sex and gender in research across disciplines. A panel of 13 experts representing nine countries developed the guidelines through a series of teleconferences, conference presentations and a 2-day workshop. An internet survey of 716 journal editors, scientists and other members of the international publishing community was conducted as well as a literature search on sex and gender policies in scientific publishing. The Sex and Gender Equity in Research (SAGER) guidelines are a comprehensive procedure for reporting of sex and gender information in study design, data analyses, results and interpretation of findings. The SAGER guidelines are designed primarily to guide authors in preparing their manuscripts, but they are also useful for editors, as gatekeepers of science, to integrate assessment of sex and gender into all manuscripts as an integral part of the editorial process.