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Background To our knowledge, no publication providing overarching guidance on the conduct of systematic reviews of observational studies of etiology exists. Methods and findings Conducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology (COSMOS-E) provides guidance on all steps in systematic reviews of observational studies of etiology, from shaping the research question, defining exposure and outcomes, to assessing the risk of bias and statistical analysis. The writing group included researchers experienced in meta-analyses and observational studies of etiology. Standard peer-review was performed. While the structure of systematic reviews of observational studies on etiology may be similar to that for systematic reviews of randomised controlled trials, there are specific tasks within each component that differ. Examples include assessment for confounding, selection bias, and information bias. In systematic reviews of observational studies of etiology, combining studies in meta-analysis may lead to more precise estimates, but such greater precision does not automatically remedy potential bias. Thorough exploration of sources of heterogeneity is key when assessing the validity of estimates and causality. Conclusion As many reviews of observational studies on etiology are being performed, this document may provide researchers with guidance on how to conduct and analyse such reviews., Author(s): Olaf M. Dekkers 1,2,3,*, Jan P. Vandenbroucke 1,3,4, Myriam Cevallos 5, Andrew G. Renehan 6, Douglas G. Altman 7, Matthias Egger 5,8 Introduction Systematic reviews aim to appraise and [...]

Background The use of core outcome sets (COS) ensures that researchers measure and report those outcomes that are most likely to be relevant to users of their research. Several hundred COS projects have been systematically identified to date, but there has been no formal quality assessment of these studies. The Core Outcome Set-STAndards for Development (COS-STAD) project aimed to identify minimum standards for the design of a COS study agreed upon by an international group, while other specific guidance exists for the final reporting of COS development studies (Core Outcome Set-STAndards for Reporting [COS-STAR]). Methods and findings An international group of experienced COS developers, methodologists, journal editors, potential users of COS (clinical trialists, systematic reviewers, and clinical guideline developers), and patient representatives produced the COS-STAD recommendations to help improve the quality of COS development and support the assessment of whether a COS had been developed using a reasonable approach. An open survey of experts generated an initial list of items, which was refined by a 2-round Delphi survey involving nearly 250 participants representing key stakeholder groups. Participants assigned importance ratings for each item using a 1-9 scale. Consensus that an item should be included in the set of minimum standards was defined as at least 70% of the voting participants from each stakeholder group providing a score between 7 and 9. The Delphi survey was followed by a consensus discussion with the study management group representing multiple stakeholder groups. COS-STAD contains 11 minimum standards that are the minimum design recommendations for all COS development projects. The recommendations focus on 3 key domains: the scope, the stakeholders, and the consensus process. Conclusions The COS-STAD project has established 11 minimum standards to be followed by COS developers when planning their projects and by users when deciding whether a COS has been developed using reasonable methods., Author(s): Jamie J. Kirkham 1, Katherine Davis 1, Douglas G. Altman 2, Jane M. Blazeby 3, Mike Clarke 4, Sean Tunis 5, Paula R. Williamson 1,* Introduction The selection of [...]

The study attempts to investigate the nature and frequency of distortion of interpretation of trial results or to distract the reader from statistically nonsignificant results for primary outcomes in published reports of randomized controlled trials (RCTs) with statistically nonsignificant results for primary outcomes. The results indicate that in the case of such RCTs, the reporting and interpretation of findings was found to be very often inconsistent with the results.

A study was conducted to compare the primary outcomes of registered trials with those reported in published trials and to determine whether primary outcome reporting bias favored significant outcomes. Results indicated that selective outcome reporting was prevalent in comparison of primary outcomes of registered randomized controlled trials (RCTs).

Microarray technology measures the mRNA levels of tens of thousands of genes in tissue samples simultaneously in a high-throughput and costeffective manner. Since its introduction over a decade ago [1], [...]

Introduction Scientific publications are one of the most important outputs of any research, as they are the primary means of sharing the findings with the broader research community. The quality [...]

Background Clear, transparent, and sufficiently detailed abstracts of conferences and journal articles related to randomized controlled trials (RCTs) are important, because readers often base their assessment of a trial solely on information in the abstract. Here, we extend the CONSORT (Consolidated Standards of Reporting Trials) Statement to develop a minimum list of essential items, which authors should consider when reporting the results of a RCT in any journal or conference abstract. Methods and Findings We generated a list of items from existing quality assessment tools and empirical evidence. A three-round, modified-Delphi process was used to select items. In all, 109 participants were invited to participate in an electronic survey; the response rate was 61%. Survey results were presented at a meeting of the CONSORT Group in Montebello, Canada, January 2007, involving 26 participants, including clinical trialists, statisticians, epidemiologists, and biomedical editors. Checklist items were discussed for eligibility into the final checklist. The checklist was then revised to ensure that it reflected discussions held during and subsequent to the meeting. CONSORT for Abstracts recommends that abstracts relating to RCTs have a structured format. Items should include details of trial objectives; trial design (e.g., method of allocation, blinding/ masking); trial participants (i.e., description, numbers randomized, and number analyzed); interventions intended for each randomized group and their impact on primary efficacy outcomes and harms; trial conclusions; trial registration name and number; and source of funding. We recommend the checklist be used in conjunction with this explanatory document, which includes examples of good reporting, rationale, and evidence, when available, for the inclusion of each item. Conclusions CONSORT for Abstracts aims to improve reporting of abstracts of RCTs published in journal articles and conference proceedings. It will help authors of abstracts of these trials provide the detail and clarity needed by readers wishing to assess a trial's validity and the applicability of its results., Introduction Well-written abstracts of conferences and journal articles reporting randomized controlled trials (RCTs) are important, because readers will often base their initial assessment of a trial on the information reported [...]

Abstract Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalizability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control and cross- sectional studies. We convened a two-day workshop, in September 2004, with methodologists, researchers and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the web sites of PLoS Medicine, Annals of Internal Medicine and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies. Resume Les recherches menees dans le domaine biomedical sont pour une grande part de nature observationnelle. Les rapports de ces etudes sont souvent inadequats, ce qui empeche l'evaluation des points forts et des defauts de l'etude et sa generalisation. L'Initiative STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) a elabore des recommandations sur ce que doit etre le contenu d'un rapport complet et precis d'etude observationnelle. Nous avons defini le champ d'application de ces recommandations comme couvrant les trois principaux types d'etude, a savoir les etudes de cohorte, cas-temoins et transversales. En septembre 2004, dans le cadre d'un atelier de deux jours, nous avons invite des methodologistes, des chercheurs et des editeurs de revue a elaborer une liste de points a considerer. Cette liste a ensuite ete revisee dans le cadre de plusieurs reunions du groupe coordinateur et de discussions par courrier electronique avec le groupe plus large des contributeurs a l'Initiative STROBE, en tenant compte de resultats empiriques et de considerations methodologiques. L'atelier et le processus iteratif ulterieur de consultation et de revision ont debouche sur une liste de controle en 22 points (la declaration STROBE) concernant le titre, le resume, l'introduction, la methodologie et les parties Resultats et Discussion des articles. Dix-huit points s'appliquent collectivement aux trois types d'etude et quatre specifiquement aux etudes de cohortes, cas-temoins ou transversales. Un document intitule Explanation and Elaboration est publie separement et accessible gratuitement sur les sites Internet PloS Medicine, Annals of lnternal Medicine et Epidemiology. Nous esperons que la declaration STROBE contribuera a l'amelioration de la qualite des rapports d'etude observationnelle. Une traduction en francais de ce resume figure a la fin de l'article. Resumen Gran parte de la investigacion biomedica es de tipo observacional, pero la informacion difundida sobre esas investigaciones es a menudo insuficiente, Io que dificulta la evaluacion de sus puntos fuertes y debiles y de su generalizabilidad de las conclusiones. En el marco de la iniciativa de Fortalecimiento de la Notificacion de los Estudios Observacionales en Epidemiologia (STROBE), se formularon recomendaciones sobre lo que deberia contener una notificacion precisa de un estudio observacional. Decidimos limitar el alcance de las recomendaciones a tres grandes modalidades de estudio: estudios de cohortes, estudios de casos y controles, y estudios transversales. En septiembre de 2004 organizamos un taller de dos dias con metodologos, investigadores y editores de revistas para elaborar una lista de verificacion de distintos puntos. Esta lista fue revisada posteriormente en varias reuniones del grupo de coordinacion y en discusiones mantenidas por e-mail con los principales participantes en STROBE, teniendo en cuenta la evidencia empirica y diversas consideraciones metodologicas. El taller y el posterior proceso iterativo de consulta y revision desembocaron en una lista de verificacion de 22 puntos (la declaracion STROBE) que guardan relacion con el titulo, el resumen, la introduccion y las secciones de metodos, resultados y discusion de los articulos. Dieciocho puntos son comunes a las tres modalidades de estudio, y cuatro se refieren especificamente a los estudios de cohortes, de casos y controles o transversales. Se ha publicado separadamente un documento de Explicacion y elaboracion al que puede accederse libremente en los sitios web de PLoS Medicine, Annals of Internal Medicine y Epidemiology. Esperamos que la declaracion STROBE contribuya a mejorar la calidad de la notificacion de los estudios observacionales. Al final del articulo se facilita una traduccion al espanol. [TEXT NOT REPRODUCIBLE IN ASCII.], Introduction Many questions in medical research are investigated in observational studies. (1) Much of the research into the cause of diseases relies on cohort, case-control or cross-sectional studies. Observational studies [...]

ABSTRACT Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and [...]

ABSTRACT Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening [...]

ABSTRACT Background Systematic reviews (SRs) have become increasingly popular to a wide range of stakeholders. We set out to capture a representative cross-sectional sample of published SRs and examine them [...]

ABSTRACT Background Ghost authorship, the failure to name, as an author, an individual who has made substantial contributions to an article, may result in lack of accountability. The prevalence and [...]

Background Core outcome sets (COS) can enhance the relevance of research by ensuring that outcomes of importance to health service users and other people making choices about health care in a particular topic area are measured routinely. Over 200 COS to date have been developed, but the clarity of these reports is suboptimal. COS studies will not achieve their goal if reports of COS are not complete and transparent. Methods and Findings In recognition of these issues, an international group that included experienced COS developers, methodologists, journal editors, potential users of COS (clinical trialists, systematic reviewers, and clinical guideline developers), and patient representatives developed the Core Outcome Set-STAndards for Reporting (COS-STAR) Statement as a reporting guideline for COS studies. The developmental process consisted of an initial reporting item generation stage and a two-round Delphi survey involving nearly 200 participants representing key stakeholder groups, followed by a consensus meeting. The COS-STAR Statement consists of a checklist of 18 items considered essential for transparent and complete reporting in all COS studies. The checklist items focus on the introduction, methods, results, and discussion section of a manuscript describing the development of a particular COS. A limitation of the COS-STAR Statement is that it was developed without representative views of low- and middle-income countries. COS have equal relevance to studies conducted in these areas, and, subsequently, this guideline may need to evolve over time to encompass any additional challenges from developing COS in these areas. Conclusions With many ongoing COS studies underway, the COS-STAR Statement should be a helpful resource to improve the reporting of COS studies for the benefit of all COS users., Author(s): Jamie J. Kirkham 1, Sarah Gorst 1, Douglas G. Altman 2, Jane M. Blazeby 3, Mike Clarke 4, Declan Devane 5, Elizabeth Gargon 1, David Moher 6, Jochen Schmitt [...]

An adapted Consolidated Standards of Reporting Trials (CONSORT) checklist for reporting noninferiority and equivalence trials is presented and illustrative examples and explanations for those items amended from the original CONSORT checklist are provided. The intent is to improve reporting of noninferiority and equivalence trials, enabling readers to assess the validity of their results and conclusions.

An attempt is made to examine the extent and nature of outcome reporting bias in a cohort of randomized trials. The conclusion states that the reporting of trial outcomes is biased and inconsistent with protocols.

Most medical researchers who do a factorial clinical trial are performing them appropriately and only use them for treatments that do not interact. This was the conclusion of researchers who analyzed 33 reports of 29 factorial trials. A factorial clinical trial is one that evaluates more than one treatment.

Some authors of scientific papers do not allow a person who specializes in statistics to review their paper, according to a survey of 704 authors. Even when they do, they may not include the name of the statistician in the list of authors and contributors., Context: Investigation of the nature and frequency of statistician involvement in medical research and its relation to the final editorial decision. Methods: Authors of original research articles who submitted to BMJ and Annals of Internal Medicine from May through August 2001 were sent a short questionnaire at the time of manuscript submission. Authors were asked if they received assistance from a person with statistical expertise, the nature of any such contribution, and reasons why, if no statistical input was received. Results: The response rate was 75% (704/943); methodological input was reported for 514(73%) of these papers. In 435 papers (85%), such input was provided by biostatisticians or epidemiologists and, if deemed significant, was typically associated with authorship. A total of 33 of 122 methodologists (27%) whose main contribution started at the analysis stage received neither acknowledgment nor authorship. Research without methodological assistance was more likely to be rejected without review (71% vs 57%; [chi square]=10.6; P=.001) and possibly less likely to be accepted for publication (7% vs 11%; [chi square]=2.37; P=.12). Conclusions: Statistical input to medical research is widely recommended but inconsistently obtained. Individuals providing such expertise are often not involved until the analysis of data and many go unrecognized by either authorship or acknowledgment.

Background Systematic reviews (SRs) can help decision makers interpret the deluge of published biomedical literature. However, a SR may be of limited use if the methods used to conduct the SR are flawed, and reporting of the SR is incomplete. To our knowledge, since 2004 there has been no cross-sectional study of the prevalence, focus, and completeness of reporting of SRs across different specialties. Therefore, the aim of our study was to investigate the epidemiological and reporting characteristics of a more recent cross-section of SRs. Methods and Findings We searched MEDLINE to identify potentially eligible SRs indexed during the month of February 2014. Citations were screened using prespecified eligibility criteria. Epidemiological and reporting characteristics of a random sample of 300 SRs were extracted by one reviewer, with a 10% sample extracted in duplicate. We compared characteristics of Cochrane versus non-Cochrane reviews, and the 2014 sample of SRs versus a 2004 sample of SRs. We identified 682 SRs, suggesting that more than 8,000 SRs are being indexed in MEDLINE annually, corresponding to a 3-fold increase over the last decade. The majority of SRs addressed a therapeutic question and were conducted by authors based in China, the UK, or the US; they included a median of 15 studies involving 2,072 participants. Meta-analysis was performed in 63% of SRs, mostly using standard pairwise methods. Study risk of bias/quality assessment was performed in 70% of SRs but was rarely incorporated into the analysis (16%). Few SRs (7%) searched sources of unpublished data, and the risk of publication bias was considered in less than half of SRs. Reporting quality was highly variable; at least a third of SRs did not report use of a SR protocol, eligibility criteria relating to publication status, years of coverage of the search, a full Boolean search logic for at least one database, methods for data extraction, methods for study risk of bias assessment, a primary outcome, an abstract conclusion that incorporated study limitations, or the funding source of the SR. Cochrane SRs, which accounted for 15% of the sample, had more complete reporting than all other types of SRs. Reporting has generally improved since 2004, but remains suboptimal for many characteristics. Conclusions An increasing number of SRs are being published, and many are poorly conducted and reported. Strategies are needed to help reduce this avoidable waste in research., Author(s): Matthew J. Page 1,2, Larissa Shamseer 3,4, Douglas G. Altman 5, Jennifer Tetzlaff 3, Margaret Sampson 6, Andrea C. Tricco 7,8, Ferrán Catalá-López 3,9, Lun Li 10, Emma K. [...]