Publication bias against negative results from clinical trials: Three of the seven deadly sins
Available from: Philip E Mosley
- "We do not believe it is premature to speculate in this manner prior to the publication of these results in the peerreviewed literature, although clearly this places limitations on the precision of any conclusions that can be drawn. Publication bias against negative results from clinical trials often delays or even prevents full publication from occurring (Johnson and Dickersin, 2007). We also sought to document the adverse events associated with DBS for depression, with a focus on psychiatric issues. "
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ABSTRACT: Deep brain stimulation is an experimental intervention for treatment-resistant depression. Open trials have shown a sustained response to chronic stimulation in many subjects. However, two recent randomised, double-blind, placebo-controlled trials failed to replicate these results. This article is a conceptual paper examining potential explanations for these discrepant findings.
We conducted a systematic review of the published studies obtained from PubMed and PsycINFO. Studies were selected if they directly examined the impact of deep brain stimulation on depressive symptoms. We excluded case reports and papers re-describing the same cohort of patients. We compared them with data from the placebo-controlled trials, available from Clinicaltrials.gov and abstracts of the American Society for Stereotactic and Functional Neurosurgery. We supplemented our investigation by reviewing additional publications by the major groups undertaking deep brain stimulation for mood disorders.
We selected 10 open studies reporting on eight cohorts of patients using four different operative targets. All published studies reported positive results. This was not replicated in data available from the randomised, placebo-controlled trials. Many studies reported suicide or suicide attempts in the postoperative period.
We consider the placebo effect, the pattern of network activation, surgical candidacy and design of a blinded trial including the length of a crossover period. We suggest a greater focus on selecting patients with melancholia. We anticipate that methodological refinements may facilitate further investigation of this technology for intractable depression. We conclude by noting the psychiatric adverse events that have been reported in the literature to date, as these will also influence the design of future trials of deep brain stimulation for depression.
© The Royal Australian and New Zealand College of Psychiatrists 2015.
- "6) Publication bias. There is also evidence showing the impact of publication bias in the literature reporting mtDNA association studies; that is, there is a bias towards reporting significant positive results, despite these findings not necessarily being based on the best study design (Johnson and Dickersin, 2007). A recent review focusing on breast cancer demonstrated that positive findings are more frequently reported in higher-profile journals than are negative findings (Salas et al., 2014), irrespective of their study design. "
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ABSTRACT: We have set out a short guide to help prevent false positive and negative results in mitochondrial DNA (mtDNA) case-control association studies. Currently the mtDNA association literature is replete with conflicting reports. Associating mtDNA variation with common disease is a complex task, which requires a detailed understanding of the nuances of mitochondrial genetics. We present some of the reasons for the conflicting associations with possible solutions. We feel that this is important, as the continued publication of association studies that fall short of current design criteria will impact negatively on the field.
Available from: Ping Wang
- "In a review article, von Elm et al  concluded that the main reason for this was lack of time, however, some researchers responded that negative results were the major cause of nonpublication. The selective publication of “statistically significant” results is well documented, and it has been observed that a study was more likely to be published if the results were positive , . "
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ABSTRACT: After the publication of the CONSORT 2010 statement, few studies have been conducted to assess the reporting quality of randomized clinical trials (RCTs) on treatment of diabetes mellitus with Traditional Chinese Medicine (TCM) published in Chinese journals.
To investigate the current situation of the reporting quality of RCTs in leading medical journals in China with the CONSORT 2010 statement as criteria.
The China National Knowledge Infrastructure (CNKI) electronic database was searched for RCTs on the treatment of diabetes mellitus with TCM published in the Journal of Traditional Chinese Medicine, Chinese Journal of Integrated Traditional & Western Medicine, and the China Journal of Chinese Materia Medica from January to December 2011. We excluded trials reported as "animal studies", "in vitro studies", "case studies", or "systematic reviews". The CONSORT checklist was applied by two independent raters to evaluate the reporting quality of all eligible trials after discussing and comprehending the items thoroughly. Each item in the checklist was graded as either "yes" or "no" depending on whether it had been reported by the authors.
We identified 27 RCTs. According to the 37 items in the CONSORT checklist, the average reporting percentage was 45.0%, in which the average reporting percentage for the "title and abstract", the "introduction", the "methods", the "results", the "discussion" and the "other information" was 33.3%, 88.9%, 36.4%, 54.4%, 71.6% and 14.8%, respectively. In the Journal of Traditional Chinese Medicine, Chinese Journal of Integrated Traditional & Western Medicine, and the China Journal of Chinese Materia Medica the average reporting percentage was 42.2%, 56.8%, and 46.0%, respectively.
The reporting quality of RCTs in these three journals was insufficient to allow readers to assess the validity of the trials. We recommend that editors require authors to use the CONSORT statement when reporting their trial results as a condition of publication.
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