scholarly journals Network meta-analyses in reproductive medicine: challenges and opportunities

2020 ◽  
Vol 35 (8) ◽  
pp. 1723-1731
Author(s):  
Rui Wang ◽  
Anna Lene Seidler ◽  
Lisa Askie ◽  
Robert J Norman ◽  
Siladitya Bhattacharya ◽  
...  
Keyword(s):  
Reproductive Medicine ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Indirect Evidence ◽  
Future Research ◽  
Challenges And Opportunities ◽  
Recent Addition ◽  
Simultaneous Comparisons ◽  
Multiple Treatments ◽  
Meta Analyses

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.

scholarly journals Improving the transparency of meta-analyses with interactive web applications

2020 ◽  
pp. bmjebm-2019-111308
Author(s):  
Thomas P Ahern ◽  
Richard F MacLehose ◽  
Laura Haines ◽  
Deirdre P Cronin-Fenton ◽  
Per Damkier ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Web Applications ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Cancer Recurrence ◽  
Quality Criteria ◽  
Future Research ◽  
Summary Estimate ◽  
Specific Association ◽  
Meta Analyses

Increased transparency in study design and analysis is one proposed solution to the perceived reproducibility crisis facing science. Systematic review and meta-analysis—through which individual studies on a specific association are ascertained, assessed for quality and quantitatively combined—is a critical process for building consensus in medical research. However, the conventional publication model creates static evidence summaries that force the quality assessment criteria and analytical choices of a small number of authors onto all stakeholders, some of whom will have different views on the quality assessment and key features of the analysis. This leads to discordant inferences from meta-analysis results and delayed arrival at consensus. We propose a shift to interactive meta-analysis, through which stakeholders can take control of the evidence synthesis using their own quality criteria and preferred analytic approach—including the option to incorporate prior information on the association in question—to reveal how their summary estimate differs from that reported by the original analysts. We demonstrate this concept using a web-based meta-analysis of the association between genetic variation in a key tamoxifen-metabolising enzyme and breast cancer recurrence in tamoxifen-treated women. We argue that interactive meta-analyses would speed consensus-building to the degree that they reveal invariance of inferences to different study selection and analysis criteria. On the other hand, when inferences are found to differ substantially as a function of these choices, the disparities highlight where future research resources should be invested to resolve lingering sources of disagreement.

A Stepwise Approach to Systematic Reviews and Meta-analyses of Endovascular Interventions

2020 ◽  
Vol 27 (5) ◽  
pp. 805-817
Author(s):  
George A. Antoniou ◽  
Giuseppe Biondi-Zoccai ◽  
Francesco Versaci ◽  
Stavros A. Antoniou
Keyword(s):  
Systematic Reviews ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Evidence Base ◽  
Future Research ◽  
Specific Topic ◽  
Stepwise Approach ◽  
Endovascular Interventions ◽  
Statistical Precision ◽  
Meta Analyses

The accrual of clinical studies poses important challenges to researchers and practitioners, especially in the field of endovascular therapy, where patient, lesion, technique, and device subtleties abound. Systematic reviews and meta-analyses may prove particularly fruitful in such settings by increasing statistical precision and bolstering external validity if the evidence base on a specific topic is consistent or by highlighting important discrepancies in the opposite scenario. However, mastering the correct approach to systematic review and meta-analysis is challenging for careful readers or for those interested in conducting such an evidence synthesis exercise. The present article highlights a stepwise approach to systematic reviews and meta-analyses, focusing on endovascular interventions, which will prove useful to anyone reading or wishing to synthesize the evidence base on endovascular topics to optimize decision making or shape future research efforts.

Challenges and Opportunities for Neuroimaging in Young Patients with Traumatic Brain Injury: a Coordinated Effort towards Advancing Discovery from the ENIGMA Pediatric Moderate/Severe TBI Group

2019 ◽  
Author(s):  
Emily L. Dennis ◽  
Karen Caeyenberghs ◽  
Robert F. Asarnow ◽  
Talin Babikian ◽  
Brenda Bartnik-Olson ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Meta Analysis ◽  
Young Patients ◽  
Future Research ◽  
Childhood And Adolescence ◽  
Developmental Issues ◽  
Challenges And Opportunities ◽  
Severe Tbi ◽  
Advance Research

Traumatic brain injury (TBI) is a major cause of death and disability in children in both developed and developing nations. Children and adolescents suffer from TBI at a higher rate than the general population; however, research in this population lags behind research in adults. This may be due, in part, to the smaller number of investigators engaged in research with this population and may also be related to changes in safety laws and clinical practice that have altered length of hospital stays, treatment, and access to this population. Specific developmental issues also warrant attention in studies of children, and the ever-changing context of childhood and adolescence may require larger sample sizes than are commonly available to adequately address remaining questions related to TBI. The ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Pediatric Moderate-Severe TBI (msTBI) group aims to advance research in this area through global collaborative meta-analysis. In this paper we discuss important challenges in pediatric TBI research and opportunities that we believe the ENIGMA Pediatric msTBI group can provide to address them. We conclude with recommendations for future research in this field of study.

scholarly journals Deriving percentage study weights in multi-parameter meta-analysis models: with application to meta-regression, network meta-analysis and one-stage individual participant data models

2017 ◽  
Vol 27 (10) ◽  
pp. 2885-2905 ◽  
Author(s):  
Richard D Riley ◽  
Joie Ensor ◽  
Dan Jackson ◽  
Danielle L Burke
Keyword(s):  
Meta Analysis ◽  
Information Matrix ◽  
Indirect Evidence ◽  
Parameter Estimates ◽  
Individual Participant Data ◽  
One Stage ◽  
Individual Participant ◽  
Meta Regression ◽  
Multiple Treatments ◽  
Analysis Models

Many meta-analysis models contain multiple parameters, for example due to multiple outcomes, multiple treatments or multiple regression coefficients. In particular, meta-regression models may contain multiple study-level covariates, and one-stage individual participant data meta-analysis models may contain multiple patient-level covariates and interactions. Here, we propose how to derive percentage study weights for such situations, in order to reveal the (otherwise hidden) contribution of each study toward the parameter estimates of interest. We assume that studies are independent, and utilise a decomposition of Fisher’s information matrix to decompose the total variance matrix of parameter estimates into study-specific contributions, from which percentage weights are derived. This approach generalises how percentage weights are calculated in a traditional, single parameter meta-analysis model. Application is made to one- and two-stage individual participant data meta-analyses, meta-regression and network (multivariate) meta-analysis of multiple treatments. These reveal percentage study weights toward clinically important estimates, such as summary treatment effects and treatment-covariate interactions, and are especially useful when some studies are potential outliers or at high risk of bias. We also derive percentage study weights toward methodologically interesting measures, such as the magnitude of ecological bias (difference between within-study and across-study associations) and the amount of inconsistency (difference between direct and indirect evidence in a network meta-analysis).

The Student Risk Screening Scale: A Reliability and Validity Generalization Meta-Analysis

2017 ◽  
Vol 26 (3) ◽  
pp. 143-155 ◽  
Author(s):  
Stephen P. Kilgus ◽  
Katie Eklund ◽  
Daniel M. Maggin ◽  
Crystal N. Taylor ◽  
Amanda N. Allen
Keyword(s):  
Internal Consistency ◽  
Externalizing Behavior ◽  
Meta Analysis ◽  
Reliability And Validity ◽  
Future Research ◽  
Risk Screening ◽  
Validity Generalization ◽  
Meta Analyses ◽  
Student Risk ◽  
Screening Scale

The purpose of this study was to conduct reliability and validity generalization meta-analyses of evidence regarding the Student Risk Screening Scale (SRSS), a universal screener for externalizing behavior problems. A systematic review of the literature resulted in the identification of 17 studies inclusive of evidence regarding SRSS score (a) internal consistency reliability (i.e., alpha coefficients), and/or (b) criterion-related validity (e.g., correlations between the SRSS and various outcomes). Multilevel meta-analyses indicated that across studies, SRSS scores were associated with adequate internal consistency (α = .83). Analyses further suggested the SRSS was a valid indicator of both social and behavioral outcomes ( r = .52) and academic outcomes ( r = .42). Follow-up analyses suggested that in accordance with theory-driven expectations, the SRSS was a stronger indicator of externalizing problems and broad behavior outcomes relative to alternative outcomes (e.g., internalizing problems). Limitations and directions for future research are discussed, including recommendations for the collection of additional SRSS diagnostic accuracy evidence.

scholarly journals Planning a future randomized clinical trial based on a network of relevant past trials

2018 ◽  
Author(s):  
Georgia Salanti ◽  
Adriani Nikolakopoulou ◽  
Alex J Sutton ◽  
Stephan Reichenbach ◽  
Sven Trelle ◽  
...  
Keyword(s):  
Trial Design ◽  
Randomized Clinical Trials ◽  
Guideline Development ◽  
Meta Analysis ◽  
Indirect Evidence ◽  
Public Health Decision ◽  
Relapsing Remitting ◽  
Health Decision ◽  
Meta Analyses ◽  
Relapsing Remitting Multiple Sclerosis

ABSTRACTBackground: The important role of network meta-analysis of randomized clinical trials in health technology assessment and guideline development is increasingly recognized. This approach has the potential to obtain conclusive results earlier than with new standalone trials or conventional, pairwise meta-analyses.Methods: Network meta-analyses can also be used to plan future trials. We introduce a four-steps framework to plan a new trial that aims to identify the optimal new design that will update the existing evidence to best serve timely clinical and public health decision making. The new trial designed within this framework does not need to include all competing interventions and comparisons of interest and can contribute direct and indirect evidence to the updated network meta-analysis. We present the method by virtually planning a new trial to compare biologics in rheumatoid arthritis and a new trial to compare two drugs for relapsing-remitting multiple sclerosis.Results: A trial design based on updating the evidence from a network meta-analysis of relevant previous trials may require a considerably smaller sample size to reach the same conclusion compared with a trial designed and analyzed in isolation. Challenges in the approach include the complexity of the methodology and the need for a coherent network meta-analysis of previous trials with little heterogeneity.Conclusions: When used judiciously, conditional trial design could significantly reduce waste in clinical research.

scholarly journals Comparing Bayesian Posterior Passing with Meta-analysis

2020 ◽  
Author(s):  
Joshua Pritsker
Keyword(s):  
Publication Bias ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Future Research ◽  
Meta Analyses

Brand, von der Post, Ounsley, and Morgan (2019) introduced Bayesian posterior passing as an alternative to traditional meta-analyses. In this commentary I relate their procedure to traditional meta-analysis, showing that posterior passing is equivalent to fixed effects meta-analysis. To overcome the limitations of simple posterior passing, I introduce improved posterior passing methods to account for heterogeneity and publication bias. Additionally, practical limitations of posterior passing and the role that it can play in future research are discussed.

scholarly journals Obsessive healthy eating and orthorexic eating tendencies in sport and exercise contexts: A systematic review and meta-analysis

2021 ◽  
Author(s):  
Jana Strahler ◽  
Hanna Wachten ◽  
Anett Mueller-Alcazar
Keyword(s):  
Systematic Review ◽  
Gender Differences ◽  
Healthy Eating ◽  
Meta Analysis ◽  
Group Analysis ◽  
Future Research ◽  
Exercise Behaviors ◽  
Sport And Exercise ◽  
Underlying Mechanisms ◽  
Meta Analyses

AbstractBackgroundOrthorexia Nervosa (ON) and exercise addiction (ExAdd) are two phenomena believed to overlap. We conducted a meta-analysis exploring the link between ON and (addictive) exercise behaviors.MethodsA systematic review of major databases and gray literature was carried out for studies reporting on ON and (addictive) exercise behaviors. Random effects meta-analyses were undertaken calculating correlations between ON and (addictive) exercise behaviors. A sub-group analysis investigated gender differences.ResultsTwenty-five studies with 10,134 participants (mean age = 25.21; 56.4% female) were included. Analyses showed a small overall correlation between ON and exercise (21 studies, r = 0.12, 95% CI |0.06–0.18|) and a medium overall correlation between ON and ExAdd (7 studies, r = 0.29, 95% CI |0.13–0.45|). Gender differences were negligible.ConclusionsOrthorexic eating correlated slightly and moderately with exercise and ExAdd, respectively, expressing some unique and shared variance of these behaviors. While this does not suggest ON and addictive exercising to be independent, it does not indicate substantial comorbidity. Future research should focus on clinical relevance, underlying mechanisms, vulnerability, and risk factors.

Internet Use and Psychological Well-Being

2012 ◽  
pp. 302-314 ◽  
Author(s):  
Chiungjung Huang
Keyword(s):  
Social Networking ◽  
Social Networking Sites ◽  
Internet Use ◽  
Meta Analysis ◽  
Well Being ◽  
Social Networking Site ◽  
Future Research ◽  
Psychological Well Being ◽  
Site Use ◽  
Meta Analyses

The direction of the correlation between Internet use and psychological well-being is debatable. The displacement hypothesis indicates the correlation is negative, as Internet use for communication replaces face-to face-interaction. Conversely, the augmentation hypothesis suggests that the correlation is positive because Internet use for communication complements existing social interaction. While previous empirical findings about the relationship between Internet use and psychological well-being have been diverse, two previous meta-analyses and the present meta-analysis about the use of social networking sites and psychological well-being supported neither position, and found no relationship between Internet use and psychological well-being. Investigation of causal predominance between Internet use and psychological well-being, increased attention to measurement problems of social networking site use and older adults, and consideration of effects of indicators and moderators should be addressed in future research.

scholarly journals The Impact of Green Space on Violent Crime in Urban Environments: An Evidence Synthesis

2019 ◽  
Vol 16 (24) ◽  
pp. 5119 ◽  
Author(s):  
Mardelle Shepley ◽  
Naomi Sachs ◽  
Hessam Sadatsafavi ◽  
Christine Fournier ◽  
Kati Peditto
Keyword(s):  
Violent Crime ◽  
Quantitative Methods ◽  
Green Space ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Urban Environments ◽  
Tree Cover ◽  
Future Research ◽  
Community Perception ◽  
The Impact

Can the presence of green space in urban environments reduce the frequency of violent crime? To ascertain the evidence on this topic, we conducted an in-depth literature review using the PRISMA checklist. The search parameters included US articles written in English and published since 2000. More than 30,000 potential paper titles were identified and ultimately, 45 papers were selected for inclusion. Green spaces typically comprised tree cover, parks and ground cover. Criminal behaviors typically included murder, assault, and theft. The majority of the research reviewed involved quantitative methods (e.g., comparison of green space area to crime data). We extracted multiple mechanisms from the literature that may account for the impact of green space on crime including social interaction and recreation, community perception, biophilic stress reduction, climate modulation, and spaces expressing territorial definition. Recommendations are made for future research, such as meta-analysis of existing data and the development of grounded theory through qualitative data-gathering methods. By providing evidence that access to nature has a mitigating impact on violence in urban settings, city governments and communities are empowered to support these interventions.

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