Positive Results Bias and Impact Factor in Retina Clinical Trials 2016-2019

Retina ◽  
2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Ankur Parikh ◽  
Jonathan Markle ◽  
Michael Venincasa ◽  
Ajay E. Kuriyan ◽  
Mrinali Gupta ◽  
...  
2021 ◽  
Vol 28 ◽  
Author(s):  
Douglas Henrique Pereira Damasceno ◽  
Arthur Aguiar Amaral ◽  
Cecília Andrade Silva ◽  
Ana Cristina Simões e Silva

Background: The COVID-19 pandemic demanded a global effort towards quickly developing safe and effective vaccines against SARS-CoV-2. Objective: This review aimed to discuss the main vaccines available, their mechanisms of action, results of clinical trials and epidemiological behavior. The implications of viral variants were also debated. Methods: A non-systematic literature review was performed between February and March 2021 by searching the Pubmed, Scopus, and SciELO databases, using different combinations of the following terms: "vaccines", "clinical trials" , "SARS-CoV-2", "Coronavirus", "COVID-19", "mechanisms of action". Data regarding clinical trials of SARS-CoV-2 vaccines and epidemiological information were also searched. Results: The mechanisms of action included vector-virus, mRNA and inactivated virus vaccines. The vaccines showed positive results in phases 2/3 clinical trials. The efficacy of the mRNA 1273 and of mRNA BNT 162b2 vaccines were 94.1% and 95%, respectively. The effectiveness of the ChAdOx1 nCoV-19 vaccine varied according to the scheme, with an overall value of 70.4%. The Gam-COVID-Vac vaccine had an efficacy of 91.6%. Regarding the Ad26.COV2.S vaccine, 99% or more of seroconversion was observed in all subgroups 29 days after vaccination. The CoronaVac vaccine induced an immune response in 92% of the volunteers receiving 3ug and in 98% with 6ug, in comparison to 3% in the placebo group. Conclusion: Global efforts have resulted in vaccines available in record time, with good safety and immunogenicity profile. However, only long-term studies can provide more information on duration of immunity and the need for additional doses.


2019 ◽  
Vol 16 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Svetlana G. Makarova ◽  
Leyla S. Namazova-Baranova ◽  
Oksana A. Ereshko ◽  
Dmitry S. Yasakov ◽  
Pavel E. Sadchikov

Intestinal microbiota is the factor that identifies considerably the human health. The impact of the microbial factor on a child begins long before his birth. Children have certain features in forming of immune response and intestinal microbiocenosis even before birth. Decline in diversity of intestinal microbiota is common in children with allergic disease even during first months of life, before allergic pathology development. Capabilities for microbiota development adjustment are sufficiently restricted. However it is clinically proven that early (within the first hours of life) breastfeeding attachment, breastfeeding itself within at least first 6 months of life, the use of prebiotics in milk formulas as well as the use of probiotics can give positive results on allergy management. In this review we present results of recent metaanalyses and consensus papers of international medical communities about use of probiotics and prebiotics in prevention and treatment of allergic diseases. Despite great scientific and practical interest to this topic, authors of metaanalyses bring our attention to the lack of evidence-based clinical trials.


Cartilage ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 339-345 ◽  
Author(s):  
Florian Frehner ◽  
Jan P. Benthien

Objective This study is a literature review from 2010 to 2014 concerning the quality of evidence in clinical trials about microfracture in attempt to repair articular cartilage. We have decided to focus on microfracturing, since this seems to be the best documented technique. Interest in evaluation of publication quality has risen in orthopaedic sports medicine recently. Therefore, we think it is necessary to evaluate recent clinical trials being rated for their evidence-based medicine (EBM) quality. We also compared the mean impact factor of the journals publishing the different studies as an indicator of the study’s citation and evaluated for a change over the studied time frame. Design To measure the EBM level, we applied the modified Coleman Methodology Score (CMS) introduced by Jakobsen. The impact factor, which is a measurement of the yearly average number of citations of articles recently published in that journal, was evaluated according to self-reported values on the corresponding journal’s website. Results We found that the mean CMS has not changed between 2010 and 2014. The mean impact factor has also not changed between 2010 and 2014. The CMS variance was high, pointing to different qualities in the evaluated studies. There is no evidence that microfracturing is superior compared to other cartilage repair procedures. Conclusion Microfracture cannot be seen as an evidence based procedure. Further research needs to be done and a standardization of the operating method is desirable. There need to be more substantial studies on microfracturing alone without additional therapies.


Author(s):  
Colin Baigent ◽  
Richard Peto ◽  
Richard Gray ◽  
Natalie Staplin ◽  
Sarah Parish ◽  
...  

Clinical trials generally need to be able to detect or to refute realistically moderate (but still worthwhile) differences between treatments in long-term disease outcome. Large-scale randomized evidence should be able to detect such effects, but medium-sized trials or medium-sized meta-analyses can, and often do, yield false-negative or exaggeratedly positive results. Hundreds of thousands of premature deaths each year could be avoided by seeking appropriately large-scale randomized evidence about various widely practicable treatments for the common causes of death, and by disseminating this evidence appropriately. This chapter takes a look at the use of large-scale randomized evidence—produced from trials and meta-analysis of trials—and how this data should be handled in order to produce accurate result.


2020 ◽  
Vol 49 (6) ◽  
pp. 708-712
Author(s):  
John A. Kellum

<b><i>Introduction:</i></b> Reports of consensus conferences are usually valued less than reports of clinical trials even when rigorous methodology is used. However, limited data are available comparing the impact of these 2 methods of shaping clinical practice. <b><i>Objective:</i></b> Compare the publication impact of consensus conferences and clinical trials. <b><i>Methods:</i></b> Consensus publications from the Acute Disease Quality Initiative (ADQI) from 2002 through 2017 were identified and classified by subject matter. Randomized trials were identified in the same publication year and subject in journals, starting with the highest impact factor. Both publication types were matched, and total citations were determined for each using Google Scholar. A secondary analysis compared total costs for each publication type. <b><i>Results and Conclusions:</i></b> Seventeen ADQI consensus conference reports and 17 randomized trials were identified. ADQI reports received a similar number of citations per paper (median, interquartile range) compared to randomized trials (132, 54–228; vs. 159, 60–340, <i>p</i> = ns). Similarly, 10 (58.8%) ADQI reports and 10 randomized trials were cited &#x3e;100 times. On average, ADQI reports appeared in journals with lower impact factors compared to clinical trials (5.4 ± 4.6 vs. 25.4 ± 27.1; <i>p</i> &#x3c; 0.01). The median cost per citation (USD 2017) for ADQI reports was USD 606.01 compared to almost twice this figure, USD 1,182.59, for clinical trials on the same topics (<i>p</i> = 0.09). Despite being published in lower impact factor journals, consensus reports on topics in critical care nephrology, received similar citations to randomized controlled trials published the same year.


2020 ◽  
Vol 17 (2) ◽  
pp. 112-125 ◽  
Author(s):  
Kelly Ceyzériat ◽  
Thomas Zilli ◽  
Philippe Millet ◽  
Giovanni B. Frisoni ◽  
Valentina Garibotto ◽  
...  

Alzheimer’s Disease (AD) is the most common neurodegenerative disease and cause of dementia. Characterized by amyloid plaques and neurofibrillary tangles of hyperphosphorylated Tau, AD pathology has been intensively studied during the last century. After a long series of failed trials of drugs targeting amyloid or Tau deposits, currently, hope lies in the positive results of one Phase III trial, highly debated, and on other ongoing trials. In parallel, some approaches target neuroinflammation, another central feature of AD. Therapeutic strategies are initially evaluated on animal models, in which the various drugs have shown effects on the target (decreasing amyloid, Tau and neuroinflammation) and sometimes on cognitive impairment. However, it is important to keep in mind that rodent models have a less complex brain than humans and that the pathology is generally not fully represented. Although they are indispensable tools in the drug discovery process, results obtained from animal models must be viewed with caution. In this review, we focus on the current status of disease-modifying therapies targeting amyloid, Tau and neuroinflammation with particular attention on the discrepancy between positive preclinical results on animal models and failures in clinical trials.


2014 ◽  
Vol 40 (8) ◽  
pp. 858-861 ◽  
Author(s):  
Michael Mimouni ◽  
Mark Krauthammer ◽  
Assaf Gershoni ◽  
Francis Mimouni ◽  
Ronit Nesher

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