Reduce Publication Bias Research Articles

Foreword: Conference Bias

Foreword: Conference Bias

“Hardly worth the effort”? Medical journals’ policies and their editors’ and publishers’ views on trial registration and publication bias: quantitative and qualitative study

Objectives To determine the proportion of medical journals requiring trial registration and to understand their reasons for adopting (or not adopting) such policies and other measures designed to reduce publication...

Meta-analysis of alcohol price and income elasticities - with corrections for publication bias.

BackgroundThis paper contributes to the evidence-base on prices and alcohol use by presenting meta-analytic summaries of price and income elasticities for alcohol beverages. The analysis improves on previous meta-analyses by correcting for outliers and publication bias.MethodsAdjusting for outliers is important to avoid assigning too much weight to studies with very small standard errors or large effect sizes. Trimmed samples are used for this purpose. Correcting for publication bias is important to avoid giving too much weight to studies that reflect selection by investigators or others involved with publication processes. Cumulative meta-analysis is proposed as a method to avoid or reduce publication bias, resulting in more robust estimates. The literature search obtained 182 primary studies for aggregate alcohol consumption, which exceeds the database used in previous reviews and meta-analyses.ResultsFor individual beverages, corrected price elasticities are smaller (less elastic) by 28-29 percent compared with consensus averages frequently used for alcohol beverages. The average price and income elasticities are: beer, -0.30 and 0.50; wine, -0.45 and 1.00; and spirits, -0.55 and 1.00. For total alcohol, the price elasticity is -0.50 and the income elasticity is 0.60.ConclusionsThese new results imply that attempts to reduce alcohol consumption through price or tax increases will be less effective or more costly than previously claimed.

‘Focus on feet’ – the effects of systemic lupus erythematosus: a narrative review of the literature

The manifestations of systemic lupus erythematosus (SLE) vary between individuals, from the severe and life-threatening renal and central nervous system involvement, to the involvement of skin, musculoskeletal and vascular system, and the complications of infection influencing the quality of life. However, as specific manifestations affecting the lower limb are perceived as receiving little focus, the purpose of this narrative literature review is to identify the specific factors associated with SLE that may have implications for lower limb and foot morbidity. A structured search of databases was conducted. The inclusion was restricted to publications in the English language, those that specifically investigate the feet as affected with SLE. No restriction on year of publication was imposed to reduce publication bias and to capture as many publication in relation to feet. Eleven papers fulfilled the inclusion criteria. There were seven additional papers that made observations related to the articular or vascular complications of the feet. This narrative review provides some information on how SLE affects the lower limb and foot in relation to the musculoskeletal and vascular systems. However, there is a lack of literature that specifically focuses on all the manifestations of SLE and the complications associated with its management. There are indications that SLE affects lower limb and foot morbidity but the scale of these problems is unclear and this is partly because of the absence of research and the lack of a 'gold standard' framework for the assessment of the lower limb and foot. In addition to clinical foot health assessment, ultrasonography may be a useful alternative to plain film radiography or magnetic resonance imaging (MRI) in capturing the extent of articular and extra-articular manifestations. Further, the Ankle Brachial Pressure Index (ABPI) may be useful in identifying those with atherosclerosis and ischaemia. There are indications that SLE affects lower limb and foot morbidity but the scale of these problems and effective management of them is unclear. Therefore, further research is warranted in order to better understand the impact of SLE on the foot and lower limb and its impact on quality of life.

A two-step manuscript submission process can reduce publication bias

Much of what is researched is never published. This would not be of great concern if the selection of what we read would occur irrespective of study outcomes. Unfortunately, the reverse is the case: “positive” studies have a much larger chance of acceptance after editorial and peer review than “negative” ones. Several solutions to this problem of publication bias have been discussed or implemented, but none seem to be very effective.In this article, the approach of implementing an editorial and peer-review procedure that is blinded to study outcomes is discussed. This would require a two-step submission procedure of manuscripts: first a version including just the introduction and methods and in some cases followed by a second submission including results and discussion. The pros and cons of such an approach are discussed.

Registration of Clinical Trials: Is it Really Needed?

Background and Aims:Withholding findings of clinical trials for publication or presentation to the regulatory authorities is a major concern. We aimed to address the importance of clinical trial registration and whether it is needed or not.Discussion:For ethical conduct of clinical trial, registration is an important but debatable issue due to proprietary interest of the pharmaceutical industry. Over the years, investigating agencies uncovered several instances of misconduct during the clinical trial. The International committee of medical journal editors requires registration of trial methodology, but does not require registration of trial results; however, the U.S. Food and Drug Administration Amendments does require researchers to register results.Conclusion:Prospective registration of clinical trial is mandatory for more transparent research and sustaining the validity of evidence based practice and availability of reliable data. Clinical trials registration has the potential to contribute substantially to improve clinical trial transparency and reducing publication bias and selective reporting.

Meta-Analysis of Alcohol Price and Income Elasticities – With Corrections for Publication Bias

Background: This paper contributes to the evidence-base on prices and alcohol use by presenting meta-analytic summaries of price and income elasticities for alcohol beverages. The analysis improves on previous meta-analyses by correcting for outliers and publication bias. Methods: Adjusting for outliers is important to avoid assigning too much weight to studies with very small standard errors or large effect sizes. Trimmed samples are used for this purpose. Correcting for publication bias is important to avoid giving too much weight to studies that reflect selection by investigators or others involved with publication processes. Cumulative meta-analysis is proposed as a method to avoid or reduce publication bias, resulting in more robust estimates. The literature search obtained 182 primary studies for aggregate alcohol consumption, which exceeds the database used in previous reviews and meta-analyses. Results: For individual beverages, corrected price elasticities are smaller (less elastic) by 28-29 percent compared with consensus averages frequently used for alcohol beverages. The average price and income elasticities are: beer, -0.30 and 0.50; wine, -0.45 and 1.00; and spirits, -0.55 and 1.00. For total alcohol, the price elasticity is -0.50 and the income elasticity is 0.60. Conclusions: These new results imply that attempts to reduce alcohol consumption through price or tax increases will be less effective or more costly than previously claimed.

Can We Depend on Investigators to Identify and Register Randomized Controlled Trials?

PurposeTo reduce publication bias, systematic reviewers are advised to search conference abstracts to identify randomized controlled trials (RCTs) conducted in humans and not published in full. We assessed the information provided by authors to aid identification of RCTs for reviews.MethodsWe handsearched the Association for Research in Vision and Ophthalmology (ARVO) meeting abstracts for 2004 to 2009 to identify reports of RCTs. We compared our classification with that of authors (requested by ARVO 2004–2006), and authors’ report of trial registration (required by ARVO 2007–2009).ResultsAuthors identified their study as a clinical trial for 169/191 (88%; 95% CI, 84–93) RCTs we identified for 2004, 174/212 (82%; 95% CI, 77–87) for 2005 and 162/215 (75%; 95% CI, 70–81) for 2006. Authors provided registration information for 107/172 (62%; 95% CI, 55–69) RCTs for 2007, 103/153 (67%; 95% CI, 60–75) for 2008, and 126/171 (74%; 95% CI, 67–80) for 2009. Most RCT authors providing a trial register name specified ClinicalTrials.gov (276/312; 88%; 95% CI, 85–92) and provided a valid ClinicalTrials.gov registration number (261/276; 95%; 95% CI, 92–97). Based on information provided by authors, trial registration information would be accessible for 48% (83/172) (95% CI, 41–56) of all ARVO abstracts describing RCTs in 2007, 63% (96/153) (95% CI, 55–70) in 2008, and 70% in 2009 (118/171) (95% CI, 62–76).ConclusionsAuthors of abstracts describing RCTs frequently did not classify them as clinical trials nor comply with reporting trial registration information, as required by the conference organizers. Systematic reviewers cannot rely on authors to identify relevant unpublished trials or report trial registration, if present.

Publication bias in psychological science: Comment on Ferguson and Brannick (2012).

It is well documented that studies reporting statistically significant results are more likely to be published than are studies reporting nonsignificant results--a phenomenon called publication bias. Publication bias in meta-analytic reviews should be identified and reduced when possible. Ferguson and Brannick (2012) argued that the inclusion of unpublished articles is ineffective and possibly counterproductive as a means of reducing publication bias in meta-analyses. We show how idiosyncratic choices on the part of Ferguson and Brannick led to an erroneous conclusion. We demonstrate that their key finding--that publication bias was more likely when unpublished studies were included--may be an artifact of the way they assessed publication bias. We also point out how the lack of transparency about key choices and the absence of information about critical features of Ferguson and Brannick's sample and procedures might have obscured readers' ability to assess the validity of their claims. Furthermore, we demonstrate that many of the claims they made are without empirical support, even though they could have tested these claims empirically, and that these claims may be misleading. With their claim that addressing publication bias introduces subjectivity and bias into meta-analysis, they ignored a large body of evidence showing that including unpublished studies that meet the inclusion criteria of a meta-analysis decreases (rather than increases) publication bias. Rather than exclude unpublished studies, we recommend that meta-analysts code study characteristics related to methodological quality (e.g., experimental vs. nonexperimental design) and test whether these factors influence the meta-analytic results.

Establishing a minimum dataset for prospective registration of systematic reviews: an international consultation.

BackgroundIn response to growing recognition of the value of prospective registration of systematic review protocols, we planned to develop a web-based open access international register. In order for the register to fulfil its aims of reducing unplanned duplication, reducing publication bias, and providing greater transparency, it was important to ensure the appropriate data were collected. We therefore undertook a consultation process with experts in the field to identify a minimum dataset for registration.Methods and FindingsA two-round electronic modified Delphi survey design was used. The international panel surveyed included experts from areas relevant to systematic review including commissioners, clinical and academic researchers, methodologists, statisticians, information specialists, journal editors and users of systematic reviews. Direct invitations to participate were sent out to 315 people in the first round and 322 in the second round. Responses to an open invitation to participate were collected separately. There were 194 (143 invited and 51 open) respondents with a 100% completion rate in the first round and 209 (169 invited and 40 open) respondents with a 91% completion rate in the second round. In the second round, 113 (54%) of the participants reported having previously taken part in the first round. Participants were asked to indicate whether a series of potential items should be designated as optional or required registration items, or should not be included in the register. After the second round, a 70% or greater agreement was reached on the designation of 30 of 36 items.ConclusionsThe results of the Delphi exercise have established a dataset of 22 required items for the prospective registration of systematic reviews, and 18 optional items. The dataset captures the key attributes of review design as well as the administrative details necessary for registration.

Thai Clinical Trials Registry

The Thai Clinical Trials Registry (TCTR) was established in 2009 by a group of university academics. The Thailand Center of Excellence for Life Sciences has supported the registry financially, while the basic infrastructure including the administration, staff and computer servers has been provided by the Clinical Research Collaboration Network and the Medical Research Foundation. In December 2010, the Ministry of Public Health of Thailand endorsed the registry. In addition to the major purposes of reducing publication bias, promoting research transparency, and reducing redundancy in clinical research, TCTR aims to create a collective database of the clinical researches in Thailand, in order to help construct a pool database for local researchers.

Publication Bias and Its Implications for Evidence‐Based Clinical Decision Making

In this review, we define and discuss several aspects of publication bias: why it occurs; its importance to dental practitioners, dental educators, and dental students; its potential to affect treatment decisions; and how it can be detected. In addition, we briefly discuss attempts to reduce publication bias. Ideally, clinical decision making should be based on the totality of evidence and not on a sample biased by the selective publication of studies that show significant results. Dentistry increasingly depends on evidence-based decision making for treatment planning and therapy. As a result we, as a profession, need to fully appreciate the potential for publication bias to hinder advancements in oral health care by decreasing the availability of scientific evidence and threatening the validity of evidence-based practice.

Publication bias in randomized controlled trials (RCTs) of colorectal cancer presented at ASCO Annual Meetings.

6116 Background: Full publication of RCTs presented as abstracts in scientific meetings may reduce publication bias, facilitate systematic reviews, and expedite implementation of therapeutic interv...

Register systematic reviews

Straus and Moher call for “a registry of protocols for systematic reviews and of completed reviews.” [1][1] We agree that such a registry would, among other things, help reduce publication bias, promote transparency and enhance collaboration. Following the lead of early registers of published

Outcomes of Drug Trials and Association with Funding Source

Web-based clinical trial registries such as ClinicalTrials.gov have been developed to increase transparency and reduce publication bias. In this study, U.S. and Canadian researchers examined more than 500 drug trials listed in that registry to investigate whether funding sources affected outcomes. …

Ergebnisregister für klinische Studien – ein Meilenstein auf dem Weg zur Transparenz klinischer Forschung?

Publication bias, i.e., the publication of trial results depending on the nature and direction of results, is a significant problem in healthcare, as it leads to a biased view of the treatment options available. Furthermore, publication bias hampers the adequate planning and conduct of future clinical trials. One proposal to reduce publication bias is the registration of trials and trial results. Whereas the registration of trials at inception is largely accepted and partly established, the registration of trial results is still being intensively discussed. Open issues particularly refer to legal obligations in the registration of trial results as well as to the nature and extent of their presentation. Whilst in the United States a comprehensive legal regulation on results registration has already been implemented, compulsory registration in Europe is still at a preliminary stage. The present paper describes the status quo of results registries, discusses registration requirements, and outlines the need to develop methods for the handling of results registries.

Quality and publication success of abstracts of randomized clinical trials in inflammatory bowel disease presented at Digestive Disease Week†

The incorporation of abstracts from scientific meetings into systematic reviews and practice guidelines may reduce publication bias and delays in implementing therapeutic interventions. All abstracts of Phase III randomized controlled trials in inflammatory bowel disease accepted at Digestive Disease Week (1998-2003) were identified. MedLine, PubMed (1997-current), EMBASE, and Google Scholar were searched for subsequent full publications. Characteristics of methodology and outcomes of the abstracts and articles were analyzed. The 5-year cumulative publication rate of the 82 eligible abstracts was 78%. Abstracts that presented negative results were less likely to be published than those with positive findings, particularly after the first 2 years (hazard ratio 6.45; 95% confidence interval [CI]: 2.22-18.7) with 5-year cumulative publication rates of (50% versus 91%, respectively, P < 0.001). The median time to publication was longer for negative than positive abstracts (58 versus 26 months, P < 0.001). Abstracts selected for oral presentation were more likely to be published than poster presentations (89% versus 69%; P = 0.03). A change in primary outcome results was observed in 28% (n = 18) of abstracts compared to that in the final publication, and 6% (n = 4) had a statistically significant change resulting in a change of study conclusions. Our findings suggest that the use of abstract data would enable detection and mitigation of publication bias. Improving the uniformity and quality of abstract reporting of randomized clinical trials at scientific meetings may facilitate their incorporation in practice guidelines and systematic reviews.

Antioxidant Supplementation and Cancer Prevention—Reply

In Reply: I agree with the comments from Drs Bosland and McCormick regarding the importance of null results from preclinical animal models and support their suggestion for reducing publication bias by increasing journal space devoted to well-conducted null studies.

Medical editors and trial reporting: A betrayal of patient care

Medical editors and trial reporting: A betrayal of patient care

Reducing publication bias of prospective clinical trials through trial registration

Publication bias is the selective publishing of favorable or statistically significant results. This practice, over time, distorts the medical literature by depicting inordinately optimistic outcomes for treatments and interventions. Sources of publication bias include preferential publishing by journals and preferential submission by researchers. Mandatory trial registration, as instituted by the International Committe of Medical Journal Editors (ICMJE), should reduce publication bias by improving the ability to identify all trials pertaining to a specific intervention. Contraception endorses the views of the ICMJE and will now require registration of all prospective trials.