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At least 19 recordsLinked to original sources
PubMed1992

Review articles and publication bias.

Publication bias occurs if the results from studies which have not been published are different from the published ones. From a Bayesian viewpoint, it also concerns non-publication of studies with similar results as the published ones because the strength of the evidence will be influenced. Publication bias complicates the interpretation of reviews and meta-analyses. If favourable results are published more often there will be an overestimation of the effects of a treatment. There have been several attempts to assess the magnitude of publication bias. Unpublished trials could be identified by means of a survey among researchers, and the results could subsequently be compared with the outcomes of published trials. Also, the results from published trials could be compared with trials from a registry. Furthermore, the results from registered but unpublished trials could be compared with those of registered and subsequently published trials. Studies addressing publication bias have shown that it is a serious problem which complicates the interpretation of reviews. In assessments of publication bias other factors must be taken into account. These include the mode of publication: refereed journals, other journals, books, etc. Differences could also be related to the quality of trials. Finally, the source of funding may influence both the results and subsequent publication. Publication bias can only be avoided by registration of all trials before data collection is started; several of such registries have already been installed. Perhaps, if more of such registries exist, reviewers could only use registered trials for their main conclusions. All other information could then be considered sensitive to publication bias.

Meta-Analysis as Topic↗
PubMed1990

Minimizing the three stages of publication bias.

Publication bias can be considered to have three stages: (1) Prepublication bias occurs in the performance of research, caused by ignorance, sloth, greed, or the double standard applied to clinical trials but not to clinical practice. (2) Publication bias refers to basing acceptance or rejection of a manuscript on whether it supports the treatment tested. Potentially biased reviewers are of equal concern. (3) Postpublication bias occurs in publishing interpretations, reviews, and meta-analyses of published clinical trials. Bias can be minimized by (1) insisting on high-quality research and thorough literature reviews, (2) eliminating the double standard concerning peer review and informed consent applied to clinical research and practice, (3) publishing legitimate trials regardless of their results, (4) requiring peer reviewers to acknowledge conflicts of interest, (5) replacing ordinary review articles with meta-analyses, and (6) requiring the authors of reviews to acknowledge possible conflicts of interest.

Clinical Trials as Topic↗
PubMed2002

Effect of publication bias on retrieval bias.

Publication bias is the main etiologic factor in retrieval bias. The authors measured the influence a positive study outcome had on housestaff's selecting the study for presentation.

Clinical Trials as Topic↗
PubMedDate not supplied

The role of electronic journals in reducing publication bias.

Publication bias poses a threat to the validity of medical research. It is unlikely that conventional paper journals can solve the problem of selective publication of studies with striking results because of their space limitation and need to be newsworthy. Peer-reviewed electronic journals without limitation of space might provide a solution to this paradox. To maintain the integrity of medical publication, editorial policy needs to be changed to accept clinical trials for publication, based only on the methodological criteria and not on the impact of their findings.

Clinical Trials as Topic↗
PubMed1994

Publication bias and public health policy on environmental tobacco smoke.

OBJECTIVE: To examine the tobacco industry's claim that publication bias against negative studies invalidates the risk assessment of environmental tobacco smoke (ETS) conducted by the US Environmental Protection Agency and other reviews of the health effects of ETS. DESIGN: Determination of the number of published original research articles that tested the hypothesis that ETS exposure is associated with adverse health effects and that reported statistically significant ("positive") or nonsignificant ("negative") results; the number of articles that concluded that ETS is a health risk; and unpublished studies on the effects of ETS on health. PARTICIPANTS: Articles identified by a computerized search of the medical literature supplemented with material obtained from the tobacco industry and hand searching. Articles were classified as peer-reviewed journal articles or articles from sponsored symposia. MAIN OUTCOME MEASURE: The statistical significance of results reported in the article and whether or not the article concluded that ETS exposure is a health risk. RESULTS: More symposium articles than journal articles were reviews (46% vs 6%; P = .0001). More original journal articles than original symposium articles reported the use of statistical tests (96% vs 54%; P = .0001). Of articles with statistical analyses, similar proportions of journal articles and symposium articles reported statistically significant results (57% vs 47%; P = .329). The conclusions of 80% of the original journal articles were positive, compared with 51% of the original symposium articles (P = .006). CONCLUSIONS: There is no publication bias against statistically nonsignificant results on ETS in the peer-reviewed literature. The high proportion of articles in symposia that reach the conclusion that ETS is not harmful primarily results from the inclusion of review articles.

Health Policy↗
PubMed2004

Capture-recapture is a potentially useful method for assessing publication bias.

OBJECTIVES: Publication bias is a problem in systematic reviews of randomized controlled trials. The aim of this study was to assess the influence of publication bias in a systematic review of the effectiveness of Progressive Resistance Training (PRT) in older people. STUDY DESIGN AND SETTING: The relevant studies were ascertained from three sources: electronic databases, experts, and handsearching. Capture-recapture, visual inspection of funnel plots, two statistical tests, and two methods that make adjustments for publication bias, were employed to check the robustness of the conclusions of the systematic review. RESULTS: The methods employed gave broadly consistent results. Capture-recapture estimated that 3 (95% CI ) relevant studies were missed, while Trim and Fill suggested 16 studies had been missed. Both Egger's test for bias and a funnel plot regression approach suggested that publication bias was present. A selection model approach suggested that the funnel plot asymmetry observed may not be entirely due to publication bias. CONCLUSION: Capture-recapture is a potentially useful method for assessing publication bias. Further research in the form of simulation studies is required, using a variety of scenarios to investigate the extent to which each method approximates the truth.

Aged↗
PubMed2002

Abstracts of randomized controlled trials presented at the society for pediatric research meeting: an example of publication bias.

BACKGROUND: Publication bias toward studies that favor new therapies has been known to occur for the past 40 years, yet its implications are not well studied in child health. The increased interest in meta-analyses has highlighted the need to identify the totality of evidence when addressing treatment questions. OBJECTIVES: To measure the percentage of randomized controlled trials (RCTs) presented at a major pediatric scientific meeting that were subsequently published as full-length articles, to investigate factors associated with publication, and to describe the variables that change from abstract to manuscript form. DESIGN: The scientific proceedings from the Society for Pediatric Research were hand searched for RCTs (1992-1995). Subsequent publication was ascertained through a search of various electronic databases. Quality of abstracts and manuscripts was measured, and data were extracted using a structured form. RESULTS: A total of 264 (59.1%) of 447 abstracts were subsequently published. Almost 64% of RCTs that were subsequently published favored new therapy compared with 43.5% of studies that were never published (P<.001). Mean effect size for published vs unpublished RCTs was 0.74 vs 0.05 (P<.001). Median sample size was larger in published (n = 45) vs unpublished (n = 34) RCTs (P =.02). Quality was significantly lower for abstracts vs published RCTs (P<.001). For 5% of abstracts that were subsequently published, the conclusion regarding treatment efficacy changed. CONCLUSIONS: Publication bias is a serious threat to assessing the effectiveness of interventions in child health, as little more than half of RCTs presented at a major scientific meeting are subsequently published. There is a need to institute an international registry of RCTs in children so that the totality of evidence can be accessed when assessing treatment effectiveness.

Child↗
PubMed1997

Publication bias: evidence of delayed publication in a cohort study of clinical research projects.

OBJECTIVES: To determine the extent to which publication is influenced by study outcome. DESIGN: A cohort of studies submitted to a hospital ethics committee over 10 years were examined retrospectively by reviewing the protocols and by questionnaire. The primary method of analysis was Cox's proportional hazards model. SETTING: University hospital, Sydney, Australia. STUDIES: 748 eligible studies submitted to Royal Prince Alfred Hospital Ethics Committee between 1979 and 1988. MAIN OUTCOME MEASURES: Time to publication. RESULTS: Response to the questionnaire was received for 520 (70%) of the eligible studies. Of the 218 studies analysed with tests of significance, those with positive results (P < 0.05) were much more likely to be published than those with negative results (P > or = 0.10) (hazard ratio 2.32 (95% confidence interval 1.47 to 3.66), P = 0.0003), with a significantly shorter time to publication (median 4.8 v 8.0 years). This finding was even stronger for the group of 130 clinical trials (hazard ratio 3.13 (1.76 to 5.58). P = 0.0001), with median times to publication of 4.7 and 8.0 years respectively. These results were not materially changed after adjusting for other significant predictors of publication. Studies with indefinite conclusions (0.05 < or = P < 0.10) tended to have an even lower publication rate and longer time to publication than studies with negative results (hazard ratio 0.39 (0.13 to 1.12), P = 0.08). For the 103 studies in which outcome was rated qualitatively, there was no clear cut evidence of publication bias, although the number of studies in this group was not large. CONCLUSIONS: This study confirms the evidence of publication bias found in other studies and identifies delay in publication as an additional important factor. The study results support the need for prospective registration of trials to avoid publication bias and also support restricting the selection of trials to those started before a common date in undertaking systematic reviews.

Biomedical Research↗
PubMed2006

A new 'publication bias': the mode of publication.

The editor of a medical journal may influence the opinion of his readers by a 'publication bias'. This can be through the choice of an editorial at the front of the journal, tutoring the article, the choice of an author from the Editorial Board and the organization of a press conference accompanying the publication. The publicity from which certain studies benefited in recent years has had a negative effect on doctors' prescriptions and comprehension of the published studies.

Biomedical Research↗
PubMed2003

Publication bias in neurosurgery: lessons from series of unruptured aneurysms.

BACKGROUND: Bias favouring publication of research with "positive" results over studies with "negative" results is widely suspected. The present investigation addressed this problem in the field of neurosurgery through a review of recent literature concerning outcome of surgery for unruptured intracranial aneurysms. METHODS AND FINDINGS: A Medline search was performed seeking case series of surgical treatment for unruptured intracranial aneurysms that analyzed 50 or more patients. Ten type I studies (retrospective studies from a single institution; 1457 patients) met these entry criteria. In general, type I studies reported excellent surgical outcome, with mean combined mortality and morbidity of 7.8% (95% confidence interval (CI), 6.4% to 9.2%). We found 4 multicenter or community-based studies (type II studies; 5401 patients). Mean combined mortality and morbidity in the type II studies was 20.3% (95% CI, 19.2% to 21.4%), much higher than in type I studies. Relative risk was 2.6 (95% CI, 2.2 to 3.1) for patients in type II studies compared with those in type I studies. Two meta-analyses (type III studies) described combined mortality and morbidity of 5.0% and 12.7%, essentially corresponding to results of type I studies. INTERPRETATION: Publication bias is present in the neurosurgical literature. Studies with an excellent surgical outcome are more likely to be published than those with an average outcome. Conclusions of literature reviews or meta-analyses based on published work therefore may be misleading. The solution to the problem would be community-based prospective registration of all patients who underwent surgery, providing a sampling frame free from publication bias.

Humans↗
PubMed2005

In an empirical evaluation of the funnel plot, researchers could not visually identify publication bias.

BACKGROUND AND OBJECTIVE: Publication bias and related biases can lead to overly optimistic conclusions in systematic reviews. The funnel plot, which is frequently used to detect such biases, has not yet been subjected to empirical evaluation as a visual tool. We sought to determine whether researchers can correctly identify publication bias from visual inspection of funnel plots in typical-size systematic reviews. METHODS: A questionnaire with funnel plots containing 10 studies each (the median number in medical meta-analyses) was completed by 41 medical researchers, including clinical research fellows in a meta-analysis class, faculty in clinical care research, and experienced systematic reviewers. RESULTS: On average, participants correctly identified 52.5% (95% CI 50.6-54.4%) of the plots as being affected or unaffected by publication bias. The weighted mean percent correct, which adjusted for the fact that asymmetric plots are more likely to occur in the presence of publication bias, was also low (48.3 to 62.8%, depending on the presence or absence of publication bias and heterogeneous study effects). CONCLUSION: Researchers who assess for publication bias using the funnel plot may be misled by its shape. Authors and readers of systematic reviews need to be aware of the limitations of the funnel plot.

Humans↗
PubMed2004

Publication bias in situ.

BACKGROUND: Publication bias, as typically defined, refers to the decreased likelihood of studies' results being published when they are near the null, not statistically significant, or otherwise "less interesting." But choices about how to analyze the data and which results to report create a publication bias within the published results, a bias I label "publication bias in situ" (PBIS). DISCUSSION: PBIS may create much greater bias in the literature than traditionally defined publication bias (the failure to publish any result from a study). The causes of PBIS are well known, consisting of various decisions about reporting that are influenced by the data. But its impact is not generally appreciated, and very little attention is devoted to it. What attention there is consists largely of rules for statistical analysis that are impractical and do not actually reduce the bias in reported estimates. PBIS cannot be reduced by statistical tools because it is not fundamentally a problem of statistics, but rather of non-statistical choices and plain language interpretations. PBIS should be recognized as a phenomenon worthy of study - it is extremely common and probably has a huge impact on results reported in the literature - and there should be greater systematic efforts to identify and reduce it. The paper presents examples, including results of a recent HIV vaccine trial, that show how easily PBIS can have a large impact on reported results, as well as how there can be no simple answer to it. SUMMARY: PBIS is a major problem, worthy of substantially more attention than it receives. There are ways to reduce the bias, but they are very seldom employed because they are largely unrecognized.

AIDS Vaccines↗