scholarly journals Introduction to network meta-analysis for evidence synthesis

Medwave ◽  
2021 ◽  
Vol 21 (06) ◽  
pp. e8315-e8315
Author(s):  
Catalina Gracia González-Xuriguera ◽  
Laura Vergara-Merino ◽  
Luis Garegnani ◽  
Luis Ortiz-Muñoz ◽  
Nicolás Meza

This article belongs to a collaborative methodological series of narrative reviews about biostatistics and clinical epidemiology. The goal is to present basics concepts concerning the systematics reviews of multiple treatments comparisons with network meta-analysis. For clinical ques-tions with several therapeutic alternatives to be compared, the central question is how to classify or rank their effectiveness (benefit and harm) to choose the best option. The network meta-analysis aims to answer questions related to the effectiveness and safety of comparing multiple treatments by the simultaneous analysis of results raised from direct and indirect comparisons. The network geometry is the general graphical representation of the network meta-analysis and allows to understand and assess the strength of comparisons. The network meta-analysis should check several assumptions to be valid, especially the transitivity assumption, which allows assuming that there are no systematic differences among the included comparisons, except their compared interventions. Thus, it is possible to know the relative therapeutic effectiveness of each pair of interventions included in the network meta-analysis and their ranking in terms of categorization. It has been proposed to use a modified Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach considering the distinctive features of network meta-analysis to assess the certainty of the evidence for each comparison and the ranking of interventions.

2021 ◽  
Vol 7 (8) ◽  
pp. 637
Author(s):  
Shamala Gopal Rajadurai ◽  
Mari Kannan Maharajan ◽  
Sajesh K. Veettil ◽  
Divya Gopinath

The objective of this study was to assess the comparative efficacy and safety of different antifungal agents used for the treatment of oropharyngeal candidiasis (OPC) in adult patients with HIV. A systematic search was performed on the four major databases (Medline, Embase, CENTRAL and Scopus) to identify randomized controlled trials (RCTs) that evaluated the efficacy of antifungal agents in HIV patients with OPC. A network meta-analysis was performed from the data extracted from the selected studies. The agents were ranked according using surface under the cumulative ranking (SUCRA). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to determine the quality of evidence. A total of 15 trials were included in the quantitative analysis involving the data from a total of 2883 participants. Fluconazole was ranked as the most effective antifungal agent to achieve clinical cure (SUCRA = 0.87) in OPC followed by posaconazole and itraconazole. Posaconazole was ranked the most efficacious agent in achieving mycological cure (SUCRA = 0.81), followed by fluconazole. While nystatin was ranked the safest, the effect estimates of none of the other systemic antifungal agents were significantly higher than fluconazole. Based on the available evidence, fluconazole can be considered as the most effective drug in the treatment of OPC among HIV-infected adults and has a favorable safety profile, followed by posaconazole.


Medwave ◽  
2021 ◽  
Vol 21 (03) ◽  
pp. e8046-e8046
Author(s):  
Gonzalo A Bravo-Soto ◽  
Rocío Brañes ◽  
José Peña ◽  
Bruno Nervi

INTRODUCTION Gallbladder cancer is the most common malignancy of the biliary tract. Given the lack of therapeutic alternatives for advanced stage patients studies have suggested that palliative chemotherapy could benefit these patients. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis, and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified two systematic reviews including two studies overall, of which one was a randomized trial. We concluded that palliative chemotherapy may increase survival in advanced gallbladder cancer patients. However, palliative chemotherapy probably increases adverse effects. In addition, it is essential to carry out a new systematic review, since methodological errors were identified in the analysis and there is new evidence that has not been included in the previous reviews


2020 ◽  
Vol 35 (8) ◽  
pp. 1723-1731
Author(s):  
Rui Wang ◽  
Anna Lene Seidler ◽  
Lisa Askie ◽  
Robert J Norman ◽  
Siladitya Bhattacharya ◽  
...  

Abstract Network meta-analysis allows researchers to synthesise both direct and indirect evidence, thus enabling simultaneous comparisons of multiple treatments. A relatively recent addition to evidence synthesis in reproductive medicine, this approach has become increasingly popular. Yet, the underlying assumptions of network meta-analyses, which drive the validity of their findings, have been frequently ignored. In this article, we discuss the strengths and limitations of network meta-analyses. In addition, we present an overview of published network meta-analyses in reproductive medicine, summarize their challenges and provide insights into future research opportunities.


2019 ◽  
Vol 10 (5) ◽  
pp. 739-754 ◽  
Author(s):  
Lukas Schwingshackl ◽  
Guido Schwarzer ◽  
Gerta Rücker ◽  
Joerg J Meerpohl

ABSTRACTTraditional pairwise meta-analysis (PMA) is a very useful method that pools evidence from one study design type if appropriate; its widespread use in nutrition research is an important phenomenon. Recently, a promising method for more advanced evidence-synthesis, called network meta-analysis (NMA), was introduced. NMA is an extension of PMA that enables simultaneous comparison of multiple interventions. NMA combines direct evidence (i.e., trials comparing 2 interventions directly) and indirect evidence (i.e., from a connected route via ≥1 comparators, e.g. placebo) in a network of studies. NMAs have the potential to advance knowledge in the field of nutrition as they provide insights that cannot be obtained by individual 2-arm randomized controlled trials or PMA. Thus, in this perspective paper, we aim to summarize the current (methodologic) status of published NMAs in nutrition research and emphasize advances and strengths in comparison with traditional PMA through specific examples, and highlight potential pitfalls and limitations. NMA is an emerging methodology in the field of nutrition research. A PubMed search identified only 23 nutrition research-related NMAs published since the inception of journals up to January 8, 2019 (61% of them published since 2017), compared with >5000 published PMAs. Moreover, we aim to highlight the scientific concepts and standards through the use of the following NMA example: “Which type of oils/solid fats offers the greatest impact on blood lipids?” In this regard, we discuss intervention definitions, transitivity/similarity, statistical methods, description and visualization of results, inconsistency, ranking, dissemination bias, assessing the certainty of evidence by Grading of Recommendations Assessment, Development and Evaluation, and reporting guidelines. We expect that rigorously conducted NMAs based on high-quality systematic reviews will become the new evidence synthesis benchmark in nutrition research. However, caution is warranted because abuse and misinterpretations of PMA and NMA findings could hamper the scientific field and possibly decision-making regarding public policy.


Medwave ◽  
2021 ◽  
Vol 21 (03) ◽  
pp. e8164-e8164
Author(s):  
Bastián Schuller-Martínez ◽  
Nicolás Meza ◽  
Javier Pérez-Bracchiglione ◽  
Juan Víctor Ariel Franco ◽  
Cristóbal Loezar ◽  
...  

The significant increase in scientific evidence production has led to the creation of methods to facilitate evidence review and synthesis. This has turned, this has resulted in the emergence of different designs depending on the review’s objective. Evidence gap maps constitute a novel approach for literature review. They are thematic collections of a broad field of evidence, using a systematic search strategy that identifies gaps in knowledge and engages, early on, the target audience to design a friendly graphic product. Evidence maps are a tool to be considered in the roster of options available for research funders in that they are particularly useful for evidence-based decision-making and evidence-based policy development. The most commonly used formats to display the findings of evidence gap search designs are the bubble plot and the intervention-outcome framework. This article corresponds to the sixth of a series of narrative reviews on general topics of biostatistics and clinical epidemiology. The purpose of this review is to describe the principal features of evidence gap maps, highlighting their main objectives and utility, exploring the most commonly used mapping formats, and comparing this approach with other evidence synthesis designs.


Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1119 ◽  
Author(s):  
Jorge Pérez-Gómez ◽  
Santos Villafaina ◽  
José Carmelo Adsuar ◽  
Eugenio Merellano-Navarro ◽  
Daniel Collado-Mateo

The purpose of this study was to systematically review the scientific literature about the effects of supplementation with Ashwagandha (Withania somnifera) on maximum oxygen consumption (VO2max), as well as to provide directions for clinical practice. A systematic search was conducted in three electronic databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA). The inclusion criteria were: (a) VO2max data, with means ± standard deviation before and after the supplement intervention, (b) the study was randomized controlled trial (RCT), (c) the article was written in English. The quality of evidence was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A meta-analysis was performed to determine effect sizes. Five studies were selected in the systematic review (162 participants) and four were included in the meta-analysis (142 participants). Results showed a significant enhancement in VO2max in healthy adults and athletes (p = 0.04). The mean difference was 3.00 (95% CI from 0.18 to 5.82) with high heterogeneity. In conclusion, Ashwagandha supplementation might improve the VO2max in athlete and non-athlete people. However, further research is need to confirm this hypothesis since the number of studies is limited and the heterogeneity was high.


2021 ◽  
Author(s):  
Shi-chen Liu ◽  
Xiao-guang Li ◽  
Yu-li Xi ◽  
Wei Zhao

Abstract BackgroundMalocclusion is a common oral disorder. Childhood is a critical period for the development of malocclusion. This protocol will explore the clinical efficacy and safety of bracketless invisible orthosis (BIO) in the treatment of children with malocclusion.MethodsThis study will search MEDLINE, PUBMED, Cochrane Library, Web of Science, WANGFANG, VIP, CNKI, and CBM from inception to the present. We will not apply any limitations to the language and publication status. All potential randomized controlled trials (RCTs) on the efficacy of BIO for the treatment of children with malocclusion will be considered for inclusion. Two authors will independently carry out study identification, data extraction, and study quality assessment in each study. Any disagreement will be resolved through discussion with a third author. When a number of included studies are sufficient, we will conduct meta-analysis, as well as subgroup analysis and sensitivity analysis. The certainty of evidence will be appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Outcome of interest will be presented in summary of findings tables, and statistical analysis will be performed utilizing RevMan 5.4 software. DiscussionThis systematic study will summarize all available studies to investigate the clinical efficacy of BIO in treating children with malocclusion. Findings of this study will highlight efficacy and safety of BIO for the treatment of children with malocclusion for both clinical practice and future strategies. Study registrationOSF (https://osf.io/avpmx).


2020 ◽  
Vol 99 (5) ◽  
pp. 514-522 ◽  
Author(s):  
C.C. Martins ◽  
R.T. Firmino ◽  
J.J. Riva ◽  
L. Ge ◽  
A. Carrasco-Labra ◽  
...  

The goal of this systematic review and network meta-analysis was to compare the relative effects of toothpaste formulations for dentin hypersensitivity (DH), tested in randomized controlled trials (RCTs). We searched 7 databases to February 2019. Paired reviewers independently screened studies, extracted data, and performed risk of bias assessment. The outcome of interest was painful response measured through tactile, cold, and air stimuli. We conducted a random-effects Bayesian network meta-analysis using standardized mean difference (SMD) and their credible intervals (CIs) as the measure of effect for each pain stimuli. We assessed certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We included 125 RCTs (12,541 patients). For tactile stimulus, the following active ingredients showed large beneficial effects compared to fluoride with moderate certainty of evidence (SMD; 95% CI): potassium + stannous fluoride (SnF2) (3.05; 1.69–4.41), calcium sodium phosphosilicate (CSP) (2.14; 0.75–3.53), SnF2 (2.02; 1.06–2.99), potassium + hydroxyapatite (2.47; 0.3–4.64), strontium (1.43; 0.46–2.41), and potassium (1.23; 0.48–1.98). For cold stimulus, CSP showed large beneficial effects compared to fluoride (3.93; 0.34–7.53) with moderate certainty; for air stimulus, arginine (2.22; 1.45–2.99), potassium + hydroxyapatite (2.44; 0.33–4.55), potassium + SnF2 (2.28; 0.87–3.69), CSP (1.98; 0.99–2.98), and SnF2 (1.9; 1.03–2.77) showed large beneficial effects compared to fluoride with moderate to high certainty. Most toothpaste formulations showed evidence of superiority against placebo or fluorides (amine fluoride, sodium monofluorophosphate, or sodium fluoride). CSP was most beneficial for all 3 stimuli with high to moderate certainty. SnF2 alone and potassium combined with SnF2 or hydroxyapatite were beneficial for tactile and air stimulus with high to moderate certainty. Arginine was beneficial for air stimulus, and strontium and potassium were beneficial for tactile stimulus, with moderate certainty.


Medwave ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. e8184-e8184
Author(s):  
Gabriela Antúnez ◽  
Tomás Merino

INTRODUCTION Brain metastases are a common problem in oncology patients, especially in lung cancer. The usual treatment for cerebral oligometastases is whole brain radiation therapy. Given the persistent poor prognosis of this disease, other therapeutic alternatives such as stereotactic radiosurgery have been considered. However, there is no clarity regarding the effectiveness of its addition. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified 17 systematic reviews including seven studies overall, of which four were randomized trials. All trials assessed patients with brain oligometastases, but none of them included exclusively lung cancer population. We concluded that it is not possible to clearly establish whether radiosurgery decreases neurological functionality, cognitive impairment, mortality or serious adverse effects, as the certainty of the existing evidence has been assessed as very low.


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