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PloS One 2023Previously, we reviewed 1052 randomized-controlled trial abstracts presented at the American Society of Anesthesiologists annual meetings from 2001-2004. We found...
The relationship between study findings and publication outcome in anesthesia research following implementation of mandatory trial registration: A systematic review of publication bias.
Previously, we reviewed 1052 randomized-controlled trial abstracts presented at the American Society of Anesthesiologists annual meetings from 2001-2004. We found significant positive publication bias in the period examined, with the odds ratio for abstracts with positive results proceeding to journal publication over those with null results being 2.01 [95% confidence interval: 1.52, 2.66; P < 0.001]. Mandatory trial registration was introduced in 2005 as a required standard for publication. We sought to examine whether mandatory trial registration has decreased publication bias in the anesthesia and perioperative medicine literature. We reviewed all abstracts from the 2010-2016 American Society of Anesthesiologists meetings that reported on randomized-controlled trials in humans. We scored the result of each abstract as positive or null according to a priori definitions. We systematically searched for any subsequent publication of the studies and calculated the odds ratio for journal publication, comparing positive vs null studies. We compared the odds ratio from the 2010-2016 abstracts (post-mandatory trial registration) with the odds ratio from the 2001-2004 abstracts (pre-mandatory trial registration) as a ratio of odds ratios. We defined a 33% decrease in the odds ratio as significant, corresponding to a new odds ratio of 1.33. We reviewed 9789 abstracts; 1049 met inclusion criteria as randomized-controlled trials, with 542 (51.7%) of the abstracts going on to publication. The odds ratio for abstracts with positive results proceeding to journal publication was 1.28 [95% CI: 0.97, 1.67; P = 0.076]. With adjustment for sample size and abstract quality, the difference in publication rate between positive and null abstracts was statistically significant (odds ratio 1.34; 95% CI: 1.02, 1.76; P = 0.037). The ratio of odds ratios, comparing the odds ratio from the 2010-2016 abstracts (post-mandatory trial registration) to the odds ratio from the 2001-2004 abstracts (pre-mandatory trial registration), was 0.63 (95% CI: 0.43, 0.93); P = 0.021). We present the first study in the anesthesia and perioperative medicine literature that examines and compares publication bias over two discrete periods of time, prior to and after the implementation of mandatory trial registration. Our results suggest that the amount of publication bias has decreased markedly following implementation of mandatory trial registration. However, some positive publication bias in the anesthesia and perioperative medicine literature remains.
Topics: Humans; Publication Bias; Anesthesiology; Anesthesia; Sample Size; Odds Ratio
PubMed: 37235595
DOI: 10.1371/journal.pone.0282839 -
Medicine Dec 2023Metformin is an old drug used for the treatment of type 2 diabetes mellitus and can play a variety of roles by regulating the gut microbiota. The number of research...
BACKGROUND
Metformin is an old drug used for the treatment of type 2 diabetes mellitus and can play a variety of roles by regulating the gut microbiota. The number of research articles on metformin in the gut microbiota has increased annually; however, no bibliometric tools have been used to analyze the research status and hot trends in this field. This study presents a bibliometric analysis of publications on metformin and gut microbiota.
METHODS
We searched the Web of Science core collection database on June 8, 2023, for papers related to metformin and gut microbiota from 2012 to 2022. We used Microsoft Excel 2021, VOSviewer1.6.19, CiteSpace 6.2.4, and R software package "bibliometrix" 4.0.0 to analyze the countries, institutions, authors, journals, citations, and keywords of the included publications.
RESULTS
We included 517 papers, and the trend in publications increased over the last 11 years. The 517 articles were from 57 countries, including 991 institutions and 3316 authors, and were published in 259 journals. China led all countries (233 papers) and the most influential institution was the Chinese Academy of Sciences (16 papers). PLOS ONE (19 papers) was the most popular journal, and Nature (1598 citations) was the most cited journal. Li and Kim were the 2 most published authors (six papers each), and Cani (272 co-citations) was the most co-cited author. "Metabolites," "aging," and "intestinal barrier" were emerging topics in this field.
CONCLUSIONS
This bibliometric study comprehensively summarizes the research trends and progress of metformin and gut microbiota, and provides new research topics and trends for studying the effects of metformin on gut microbiota in different diseases.
Topics: Humans; Metformin; Gastrointestinal Microbiome; Diabetes Mellitus, Type 2; Academies and Institutes; Bibliometrics
PubMed: 38115325
DOI: 10.1097/MD.0000000000036478 -
The Cochrane Database of Systematic... Nov 2011In order to minimise publication bias, authors of systematic reviews often spend considerable time trying to obtain unpublished data. These include data from studies... (Review)
Review
BACKGROUND
In order to minimise publication bias, authors of systematic reviews often spend considerable time trying to obtain unpublished data. These include data from studies conducted but not published (unpublished data), as either an abstract or full-text paper, as well as missing data (data available to original researchers but not reported) in published abstracts or full-text publications. The effectiveness of different methods used to obtain unpublished or missing data has not been systematically evaluated.
OBJECTIVES
To assess the effects of different methods for obtaining unpublished studies (data) and missing data from studies to be included in systematic reviews.
SEARCH METHODS
We identified primary studies comparing different methods of obtaining unpublished studies (data) or missing data by searching the Cochrane Methodology Register (Issue 1, 2010), MEDLINE and EMBASE (1980 to 28 April 2010). We also checked references in relevant reports and contacted researchers who were known or who were thought likely to have carried out relevant studies. We used the Science Citation Index and PubMed 'related articles' feature to identify any additional studies identified by other sources (19 June 2009).
SELECTION CRITERIA
Primary studies comparing different methods of obtaining unpublished studies (data) or missing data in the healthcare setting.
DATA COLLECTION AND ANALYSIS
The primary outcome measure was the proportion of unpublished studies (data) or missing data obtained, as defined and reported by the authors of the included studies. Two authors independently assessed the search results, extracted data and assessed risk of bias using a standardised data extraction form. We resolved any disagreements by discussion.
MAIN RESULTS
Six studies met the inclusion criteria; two were randomised studies and four were observational comparative studies evaluating different methods for obtaining missing data.Methods to obtain missing dataFive studies, two randomised studies and three observational comparative studies, assessed methods for obtaining missing data (i.e. data available to the original researchers but not reported in the published study).Two studies found that correspondence with study authors by e-mail resulted in the greatest response rate with the fewest attempts and shortest time to respond. The difference between the effect of a single request for missing information (by e-mail or surface mail) versus a multistage approach (pre-notification, request for missing information and active follow-up) was not significant for response rate and completeness of information retrieved (one study). Requests for clarification of methods (one study) resulted in a greater response than requests for missing data. A well-known signatory had no significant effect on the likelihood of authors responding to a request for unpublished information (one study). One study assessed the number of attempts made to obtain missing data and found that the number of items requested did not influence the probability of response. In addition, multiple attempts using the same methods did not increase the likelihood of response. METHODS TO OBTAIN UNPUBLISHED STUDIES: One observational comparative study assessed methods to obtain unpublished studies (i.e. data for studies that have never been published). Identifying unpublished studies ahead of time and then asking the drug industry to provide further specific detail proved to be more fruitful than sending of a non-specific request.
AUTHORS' CONCLUSIONS
Those carrying out systematic reviews should continue to contact authors for missing data, recognising that this might not always be successful, particularly for older studies. Contacting authors by e-mail results in the greatest response rate with the fewest number of attempts and the shortest time to respond.
Topics: Access to Information; Documentation; Electronic Mail; Publishing; Randomized Controlled Trials as Topic
PubMed: 22071866
DOI: 10.1002/14651858.MR000027.pub2 -
Journal of Clinical Epidemiology Jul 2015To determine the effectiveness of interventions designed to prevent or reduce publication and related biases. (Review)
Review
OBJECTIVES
To determine the effectiveness of interventions designed to prevent or reduce publication and related biases.
STUDY DESIGN AND SETTING
We searched multiple databases and performed manual searches using terms related to publication bias and known interventions against publication bias. We dually reviewed citations and assessed risk of bias. We synthesized results by intervention and outcomes measured and graded the quality of the evidence (QoE).
RESULTS
We located 38 eligible studies. The use of prospective trial registries (PTR) has increased since 2005 (seven studies, moderate QoE); however, positive outcome-reporting bias is prevalent (14 studies, low QoE), and information in nonmandatory fields is vague (10 studies, low QoE). Disclosure of financial conflict of interest (CoI) is inadequate (five studies, low QoE). Blinding peer reviewers may reduce geographical bias (two studies, very low QoE), and open-access publishing does not discriminate against authors from low-income countries (two studies, very low QoE).
CONCLUSION
The use of PTR and CoI disclosures is increasing; however, the adequacy of their use requires improvement. The effect of open-access publication and blinding of peer reviewers on publication bias is unclear, as is the effect of other interventions such as electronic publication and authors' rights to publish their results.
Topics: Access to Information; Conflict of Interest; Cost-Benefit Analysis; Disclosure; Peer Review; Practice Guidelines as Topic; Program Evaluation; Prospective Studies; Publication Bias; Randomized Controlled Trials as Topic; Registries
PubMed: 25835490
DOI: 10.1016/j.jclinepi.2015.01.008 -
Systematic Reviews Dec 2023The living systematic review (LSR) approach is based on ongoing surveillance of the literature and continual updating. Most currently available guidance documents...
BACKGROUND AND OBJECTIVE
The living systematic review (LSR) approach is based on ongoing surveillance of the literature and continual updating. Most currently available guidance documents address the conduct, reporting, publishing, and appraisal of systematic reviews (SRs), but are not suitable for LSRs per se and miss additional LSR-specific considerations. In this scoping review, we aim to systematically collate methodological guidance literature on how to conduct, report, publish, and appraise the quality of LSRs and identify current gaps in guidance.
METHODS
A standard scoping review methodology was used. We searched MEDLINE (Ovid), EMBASE (Ovid), and The Cochrane Library on August 28, 2021. As for searching gray literature, we looked for existing guidelines and handbooks on LSRs from organizations that conduct evidence syntheses. The screening was conducted by two authors independently in Rayyan, and data extraction was done in duplicate using a pilot-tested data extraction form in Excel. Data was extracted according to four pre-defined categories for (i) conducting, (ii) reporting, (iii) publishing, and (iv) appraising LSRs. We mapped the findings by visualizing overview tables created in Microsoft Word.
RESULTS
Of the 21 included papers, methodological guidance was found in 17 papers for conducting, in six papers for reporting, in 15 papers for publishing, and in two papers for appraising LSRs. Some of the identified key items for (i) conducting LSRs were identifying the rationale, screening tools, or re-revaluating inclusion criteria. Identified items of (ii) the original PRISMA checklist included reporting the registration and protocol, title, or synthesis methods. For (iii) publishing, there was guidance available on publication type and frequency or update trigger, and for (iv) appraising, guidance on the appropriate use of bias assessment or reporting funding of included studies was found. Our search revealed major evidence gaps, particularly for guidance on certain PRISMA items such as reporting results, discussion, support and funding, and availability of data and material of a LSR.
CONCLUSION
Important evidence gaps were identified for guidance on how to report in LSRs and appraise their quality. Our findings were applied to inform and prepare a PRISMA 2020 extension for LSR.
Topics: Humans; Publishing; Bias; Checklist; Research Report; MEDLINE
PubMed: 38098023
DOI: 10.1186/s13643-023-02396-x -
Health Technology Assessment... Feb 2010To identify and appraise empirical studies on publication and related biases published since 1998; to assess methods to deal with publication and related biases; and to... (Review)
Review
OBJECTIVES
To identify and appraise empirical studies on publication and related biases published since 1998; to assess methods to deal with publication and related biases; and to examine, in a random sample of published systematic reviews, measures taken to prevent, reduce and detect dissemination bias.
DATA SOURCES
The main literature search, in August 2008, covered the Cochrane Methodology Register Database, MEDLINE, EMBASE, AMED and CINAHL. In May 2009, PubMed, PsycINFO and OpenSIGLE were also searched. Reference lists of retrieved studies were also examined.
REVIEW METHODS
In Part I, studies were classified as evidence or method studies and data were extracted according to types of dissemination bias or methods for dealing with it. Evidence from empirical studies was summarised narratively. In Part II, 300 systematic reviews were randomly selected from MEDLINE and the methods used to deal with publication and related biases were assessed.
RESULTS
Studies with significant or positive results were more likely to be published than those with non-significant or negative results, thereby confirming findings from a previous HTA report. There was convincing evidence that outcome reporting bias exists and has an impact on the pooled summary in systematic reviews. Studies with significant results tended to be published earlier than studies with non-significant results, and empirical evidence suggests that published studies tended to report a greater treatment effect than those from the grey literature. Exclusion of non-English-language studies appeared to result in a high risk of bias in some areas of research such as complementary and alternative medicine. In a few cases, publication and related biases had a potentially detrimental impact on patients or resource use. Publication bias can be prevented before a literature review (e.g. by prospective registration of trials), or detected during a literature review (e.g. by locating unpublished studies, funnel plot and related tests, sensitivity analysis modelling), or its impact can be minimised after a literature review (e.g. by confirmatory large-scale trials, updating the systematic review). The interpretation of funnel plot and related statistical tests, often used to assess publication bias, was often too simplistic and likely misleading. More sophisticated modelling methods have not been widely used. Compared with systematic reviews published in 1996, recent reviews of health-care interventions were more likely to locate and include non-English-language studies and grey literature or unpublished studies, and to test for publication bias.
CONCLUSIONS
Dissemination of research findings is likely to be a biased process, although the actual impact of such bias depends on specific circumstances. The prospective registration of clinical trials and the endorsement of reporting guidelines may reduce research dissemination bias in clinical research. In systematic reviews, measures can be taken to minimise the impact of dissemination bias by systematically searching for and including relevant studies that are difficult to access. Statistical methods can be useful for sensitivity analyses. Further research is needed to develop methods for qualitatively assessing the risk of publication bias in systematic reviews, and to evaluate the effect of prospective registration of studies, open access policy and improved publication guidelines.
Topics: Bias; Biomedical Research; Evidence-Based Medicine; Humans; Information Dissemination; Publication Bias; Review Literature as Topic
PubMed: 20181324
DOI: 10.3310/hta14080 -
Frontiers in Immunology 2023Autophagy in osteoarthritis (OA) has become an active area of research with substantial value and potential. Nevertheless, few bibliometric studies have systematically...
BACKGROUND
Autophagy in osteoarthritis (OA) has become an active area of research with substantial value and potential. Nevertheless, few bibliometric studies have systematically analyzed the available research in the field. The main goal of this study was to map the available literature on the role of autophagy in OA and identify global research hotspots and trends.
METHODS
The Web of Science Core Collection and Scopus databases were interrogated for studies of autophagy in OA published between 2004 and 2022. Microsoft Excel, VOSviewer and CiteSpace software were used to analyze and visualize the number of publications and associated citations, and reveal global research hotspots and trends in the autophagy in OA field.
RESULTS
732 outputs published by 329 institutions from 55 countries/regions were included in this study. From 2004 to 2022, the number of publications increased. China produced the most publications (n=456), prior to the USA (n=115), South Korea (n=33), and Japan (n=27). Scripps Research Institute (n=26) was the most productive institution. Martin Lotz (n=30) was the highest output author, while Caramés B (n=302) was the highest output author. was the most prolific and most co-cited journal. Currently, the autophagy in OA research hotspots include chondrocyte, transforming growth factor beta 1 (TGF-β1), inflammatory response, stress, and mitophagy. The emerging research trends in this field are AMPK, macrophage, senescence, apoptosis, tougu xiaotong capsule (TXC), green tea extract, rapamycin, and dexamethasone. Novel drugs targeting specific molecule such as TGF-β and AMPK have shown therapeutic potential but are still in the preclinical stage of development.
CONCLUSIONS
Research on the role of autophagy in OA is flourishing. Martin Lotz, Beatriz Caramés, and have made outstanding contributions to the field. Prior studies of OA autophagy mainly focused on mechanisms underlying OA and autophagy, including AMPK, macrophages, TGF-β1, inflammatory response, stress, and mitophagy. Emerging research trends, however, are centered around the relationship between autophagy, apoptosis, and senescence, as well as drug candidates such as TXC and green tea extract. The development of new targeted drugs that enhance or restore autophagic activity is a promising strategy for the treatment of OA.
Topics: Transforming Growth Factor beta1; AMP-Activated Protein Kinases; Autophagy; Antioxidants; Bibliometrics; Biological Products; Tea
PubMed: 36969240
DOI: 10.3389/fimmu.2023.1063018 -
Systematic Reviews Aug 2017Producing high-quality, relevant systematic reviews and keeping them up to date is challenging. Cochrane is a leading provider of systematic reviews in health. For... (Review)
Review
BACKGROUND
Producing high-quality, relevant systematic reviews and keeping them up to date is challenging. Cochrane is a leading provider of systematic reviews in health. For Cochrane to continue to contribute to improvements in heath, Cochrane Reviews must be rigorous, reliable and up to date. We aimed to explore existing models of Cochrane Review production and emerging opportunities to improve the efficiency and sustainability of these processes.
METHODS
To inform discussions about how to best achieve this, we conducted 26 interviews and an online survey with 106 respondents.
RESULTS
Respondents highlighted the importance and challenge of creating reliable, timely systematic reviews. They described the challenges and opportunities presented by current production models, and they shared what they are doing to improve review production. They particularly highlighted significant challenges with increasing complexity of review methods; difficulty keeping authors on board and on track; and the length of time required to complete the process. Strong themes emerged about the roles of authors and Review Groups, the central actors in the review production process. The results suggest that improvements to Cochrane's systematic review production models could come from improving clarity of roles and expectations, ensuring continuity and consistency of input, enabling active management of the review process, centralising some review production steps; breaking reviews into smaller "chunks", and improving approaches to building capacity of and sharing information between authors and Review Groups. Respondents noted the important role new technologies have to play in enabling these improvements.
CONCLUSIONS
The findings of this study will inform the development of new Cochrane Review production models and may provide valuable data for other systematic review producers as they consider how best to produce rigorous, reliable, up-to-date reviews.
Topics: Databases, Bibliographic; Editorial Policies; Humans; Information Storage and Retrieval; Quality Control; Review Literature as Topic
PubMed: 28760162
DOI: 10.1186/s13643-017-0542-3 -
The Journal of Hand Surgery Mar 2010Kienböck's disease is considered rare and currently affects fewer than 200,000 people in the United States. Given the inherent challenges associated with researching... (Review)
Review
PURPOSE
Kienböck's disease is considered rare and currently affects fewer than 200,000 people in the United States. Given the inherent challenges associated with researching rare diseases, the intense effort in hand surgery to treat this uncommon disorder may be influenced by publication bias in which positive outcomes are preferentially published. The specific aim of this project was to conduct a systematic review of the literature with the hypothesis that publication bias is present for the treatment of Kienböck's disease.
METHODS
We conducted a systematic review of all available abstracts associated with published manuscripts (English and non-English) and abstracts accepted to the 1992 to 2004 American Society for Surgery of the Hand (ASSH) annual meetings. Data collection included various study characteristics, direction of outcome (positive, neutral/negative), complication rates, mean follow-up time, time to publication, and length of patient enrollment.
RESULTS
Our study included 175 (124 English, 51 non-English) published manuscripts and 14 abstracts from the 1992 to 2004 annual ASSH meetings. Abstracts from published manuscripts were associated with a 53% positive outcome rate, which is lower than the 74% positive outcome rate found among other surgically treated disorders. Over the past 40 years, studies have become more positive (36% to 68%, p=.007) and are more likely to incorporate statistical analysis testing (0% to 55%, p<.001). Of the 14 abstracts accepted to ASSH, 11 were published in peer-reviewed journals. Ten of the 14 accepted abstracts were considered positive, and there was no significant difference in publication rate between studies with positive (n = 10) and negative (n = 4) outcomes (p>.999).
CONCLUSIONS
The acceptance rate for negative outcomes studies regarding Kienböck's disease is higher than for other surgical disorders. This may indicate a relative decrease in positive outcome bias among published Kienböck's disease studies compared with other surgical disorders. However, the increasing positive outcome rate for published Kienböck's disease studies over time may suggest a trend of increasing publication bias among journals toward Kienböck's disease studies.
Topics: Abstracting and Indexing; Bibliometrics; Humans; Osteonecrosis; Periodicals as Topic; Publication Bias; Publishing
PubMed: 20193856
DOI: 10.1016/j.jhsa.2009.12.003 -
PloS One 2014Systematic reviews of preclinical studies, in vivo animal experiments in particular, can influence clinical research and thus even clinical care. Dissemination bias,... (Review)
Review
BACKGROUND
Systematic reviews of preclinical studies, in vivo animal experiments in particular, can influence clinical research and thus even clinical care. Dissemination bias, selective dissemination of positive or significant results, is one of the major threats to validity in systematic reviews also in the realm of animal studies. We conducted a systematic review to determine the number of published systematic reviews of animal studies until present, to investigate their methodological features especially with respect to assessment of dissemination bias, and to investigate the citation of preclinical systematic reviews on clinical research.
METHODS
Eligible studies for this systematic review constitute systematic reviews that summarize in vivo animal experiments whose results could be interpreted as applicable to clinical care. We systematically searched Ovid Medline, Embase, ToxNet, and ScienceDirect from 1st January 2009 to 9th January 2013 for eligible systematic reviews without language restrictions. Furthermore we included articles from two previous systematic reviews by Peters et al. and Korevaar et al.
RESULTS
The literature search and screening process resulted in 512 included full text articles. We found an increasing number of published preclinical systematic reviews over time. The methodological quality of preclinical systematic reviews was low. The majority of preclinical systematic reviews did not assess methodological quality of the included studies (71%), nor did they assess heterogeneity (81%) or dissemination bias (87%). Statistics quantifying the importance of clinical research citing systematic reviews of animal studies showed that clinical studies referred to the preclinical research mainly to justify their study or a future study (76%).
DISCUSSION
Preclinical systematic reviews may have an influence on clinical research but their methodological quality frequently remains low. Therefore, systematic reviews of animal research should be critically appraised before translating them to a clinical context.
Topics: Animals; Drug Evaluation, Preclinical; Meta-Analysis as Topic; Publication Bias; Review Literature as Topic
PubMed: 25541734
DOI: 10.1371/journal.pone.0116016